Milanković, Milutin (1879 - 1958)		Modern Era Contributors to Meteorology (post World War I)

Below are checklists of Modern Era Contributors to Meteorology on postal items (stamps, souvenir sheets, aerogrammes, postal cards, etc.) and numismatic items (banknotes and coins). Catalog numbers, years of issue, and notes on the items featured are given when available. If readers know of additional information or images, please contact the authors using the e-mail addresses at the bottom of this page.

The Contributors on this page are listed in alphabetical order above, and are presented in chronological order below.

Bjerknes, Vilhelm (1862 - 1951)

Vilhelm Bjerknes was a Norwegian meteorologist. Early in his scientific career, beginning in 1890, he worked as assistant to Heinrich Hertz, and contributed to Hertz' work on electromagnetic resonance. This work eventually led to the development of radio.

Bjerknes is an important figure in 20th century meteorology: he introduced many of the common techniques and ideas used by modern meteorologists and weather forecasters. He was one of the originators of the Bergen classical school of thought in meteorology (also referred to at times as the Norwegian school). In the Bergen model, fronts are considered to be the sloping boundaries between cold and warm airmasses. They therefore have a three-dimensional structure, which was a new idea at the time.

Bjerknes was also a professor of meteorology, and published papers and books on dynamic meteorology and hydrodynamics. For example, in the paper On the Dynamic Principle of Circulatory Movements in the Atmosphere (Monthly Weather Review, October 1900), Bjerknes applied fundamental theorems in fluid motion by Helmholtz, Kelvin and Silberstein, along with others of his own discovery, to atmospheric circulation. This was one of the first papers to study dynamic meteorology in its modern framework.

In 1917, Bjerknes founded the Geophysical Institute of Bergen, with the goal of improving the country's meteorological forecast service. He established a large network of observing stations, mostly in southern Norway, that followed what was known as the "indirect" reporting method, in which detailed cloud observations were made in an attempt to compensate for the lack of upper-level sounding information (Bjerknes knew that information from upper levels was as important as information from the surface, but the modern radiosonde network had not yet been established). Starting in 1918, Bjerknes made analyses of his synoptic (i.e. large scale) weather maps, in which he integrated the available observations over large areas into complete meteorological patterns that included smaller scale features such as cold and warm fronts and their associated circulations. From his analyses, Bjerknes built a model of the cycle of the birth, development and decay of mid-latitude low pressure systems and their associated fronts. This was useful because the model could then be applied to observed patterns in order to forecast the evolution of the weather. This work was the foundation of what came to be known as the Bergen School of Meteorology. This idea still lies at the heart of the modern practice of weather forecasting.

While at the Institute, Bjerknes wrote his book On the Dynamics of the Circular Vortex with Applications to the Atmosphere and to Atmospheric Vortex and Wave Motion. It was published in 1921.

Eckener, Hugo (1868 - 1954)

Hugo Eckener was the commander of the German airship Graf Zeppelin.

In 1926 Fridtjof Nansen founded the International Association for Exploring the Arctic by Means of Airship (commonly known as "Aeroarctic"). According to its statement of purpose, Aeroarctic would support "the scientific investigation and permanent control of the Arctic by means of explorations (voyages) and by the disembarking and support of wireless stations". To this end, in 1928 Nansen discussed with Eckener the idea that Aeroarctic might sponsor the Graf Zeppelin in an Arctic mission. Through Eckener's knowledge of airships and Nansen's knowledge of weather, the two agreed that such a voyage would be feasible. Nansen wrote that "it may be understood that the object of the expedition with the Graf Zeppelin … is not merely to fly across the North Polar region and to take a few accidental observations, but it is an important link in a great scientific programme, and will give results of importance to science". He expected that such a scientific program would provide information useful in weather forecasting, agriculture, shipping, trade and air traffic, but unfortunately died before it could take place.

The Aeroarctic/Graf Zeppelin Arctic expedition took place in 1931 with Eckener in command. The trip was a success on all fronts. A large amount of information was gathered related to meteorology, terrestrial magnetism and oceanography. Weather records were kept throughout the trip and meteorological isobaric maps were constructed three times per day. Molchanov sounding balloons were successfully launched from the airship near Franz Josef Land, Severnaya Zemlya and Vaigach Island. These balloons carried small radio transmitters that relayed measurements of temperature, pressure and humidity back to the airship.

Eckener would later write of the voyage that "my expectations, in so far as they were surpassed, were realized when I saw that, respecting the Arctic in summer, no anxieties need be felt regarding meteorological disturbances. Temperatures in the upper air regions are such that fears that an ice cap can be formed on the ship can be avoided by proper navigation".

Bonnel, Ferdinand (1869 - 1945)

Ferdinand Bonnel, born in France near the border with Belgium, was a Jesuit priest and educator who worked in Sri Lanka. He founded St. Michael's College, which became known for its programs in meteorology and astronomy. Bonnel was the College director for more than 40 years.

Wilson, Charles Thomson Rees (1869 - 1959)

Charles Wilson was a Scottish physicist best remembered for his cloud chamber and for his work in atmospheric electricity.

After his studies at Cambridge University, Wilson spent a short time as a volunteer at the Ben Nevis Observatory in 1894. Ben Nevis is the highest point in Scotland, and the observatory was at the summit. Wilson found the glories (philatelic examples 1 and 2) and coronas (philatelic examples 1 and 2) in the clouds and mists of the mountain particularly beautiful and was inspired to study them. The thunderstorms he experienced there may have been the seeds of his later interest in atmospheric electricity.

The Cloud Chamber

Wilson worked from 1895 to 1900 as a researcher at the Cavendish Laboratory at Cambridge University. His starting point was the work of John Aitken (1839 - 1919), a Scottish atmospheric physicist who cooled a sample of air in an expansion chamber to cause condensation and showed that the resulting water droplets formed on small atmospheric particles such as dust. Such particles are now known as cloud condensation nuclei (CCN). Wilson developed an updated expansion chamber that came to be called the "cloud chamber" and used it to show that water droplets would also form in pure air (with no dust) if it was cooled enough to attain a very high humidity. He noticed that such droplets reacted to an electric field and hypothesized that the nuclei on which they had formed must therefore be ions (charged particles). Wilson then passed X-rays (discovered late in 1895) through the cloud chamber and found a resulting large increase in the number of cloud droplets. This experiment confirmed his hypothesis, since other researchers had established that the passage of X-rays through air makes it electrically conductive, and furthermore that air conductivity was due to the presence of ions.

Wilson demonstrated the cloud chamber to some other interested scientists in the late 1890s, including Kelvin, who had previously made some measurements of the atmospheric electrical field.

Wilson had some hopes of using his cloud chamber results as a basis for linking the behaviour of ions with the formation of clouds in the real atmosphere. In this he was unsuccessful. Such a link may not even be possible, since the conditions in the cloud chamber differ greatly from those in the real atmosphere.

In 1911, Wilson was the first to observe and photograph the tracks of alpha- and beta-particles and electrons in the cloud chamber. He described them as "little wisps and threads of clouds". The cloud chamber later provided other discoveries in the field of nuclear physics. As a result, Wilson, together with Arthur Compton, received the 1927 Nobel Prize for Physics. Wilson was cited for the invention of the cloud chamber, which the Nobel committee described as being at the heart of "his method of making the paths of electrically charged particles visible by the condensation of vapour".

Atmospheric Electricity

Wilson's interest in atmospheric electricity grew in the late 1890s. Then in 1900 he was asked by the Meteorological Council of the Royal Society to do some scientific work on the subject. To start, he made observations of the atmospheric electric field in 1900 and 1901 in Peebles, Scotland, where he used captive balloons and kites to measure the electric field strength at various heights, and also made improvements to the Kelvin electrograph technique. Within a few years he had constructed an instrument to measure the atmospheric electric potential gradient and the vertical flow of current in fair weather. Those measurements allowed him to calculate the electrical conductivity of the air. Of this work Wilson would reminisce, in an article published posthumously in 1960:

"I remember the satisfaction I had when my work led to the fulfilment of my dream of isolating a portion of the Earth's surface and measuring the charge upon it and the current flowing into it from the atmosphere".

His instrument, later called the "Wilson apparatus" by the Meteorological Office, became a standard for measurements of atmospheric electricity. Instruments with the same basic design were used at the Kew Observatory until 1979. Interestingly, data from the Wilson apparatus has also been used to reconstruct historic air pollution data in England.

Since atmospheric conductivity is almost exclusively due to the presence of ions, Wilson's measurements of electrical conductivity allowed him to calculate the concentration of those ions. He was also able to examine them in the cloud chamber. He published papers describing the cloud chamber and its uses in 1911 and 1912. In subsequent years he continued to make observations of atmospheric electricity and worked on droplet charging, thunderstorm electrification and the development of a capillary electrometer. In 1913 he was appointed Observer in Meteorological Physics at the Cambridge Solar Physics Observatory, where he carried out in particular work on thunderstorm electricity. In 1918 he was appointed Reader in Electrical Meteorology at the Cavendish Laboratory, and he was the Jacksonian Professor at Cambridge from 1925 until his retirement in 1935.

In the years after WWI, Wilson turned to the question of why the Earth's surface should retain an overall negative charge despite the observed electrical gradient (positive charge in the atmosphere, negative at the surface) which at first glance should neutralize the surface negative charge. It was known that there were electrical discharges associated with thunderstorms, and this led to the suggestion that lightning might be the replenishing agent of the surface negative charge. Wilson's cloud chamber experiments suggested another mechanism: they showed that if the CCN on which cloud droplets formed were negatively charged, more vapour would condense onto them than if they were positively charged. He therefore suggested that raindrops descending to the ground in thunderstorm areas (or possibly in other areas of unsettled weather with rain) were negatively charged, so that lightning and raindrops together could act to continuously replenish the observed surface negative charge in the presence of the overall atmospheric positive charge. To complete the picture, it was necessary to postulate that a vertical charge separation occurs in thunderstorms: negative at the base and positive at the top. The high level positive charge could migrate upward to a conducting layer (the ionosphere) which then would transfer it to all the remaining areas without thunderstorms, thus maintaining the observed electrical structure of the atmosphere and the surface. This theory has come to be known as the global atmospheric electrical circuit, and current flowing in the circuit is referred to as the Wilson current. Even today all the details have not been worked out, but the general theory is well-accepted. Wilson published these ideas in various papers including those of 1921, 1929 and 1956.

References (some scientific papers by Wilson)

• Wilson, C.T.R., 1899: On the condensation nuclei produced in gases by the action of Rontgen rays, uranium rays, ultraviolet light and other agents, Phil. Trans. Roy. Soc. Lond. A, 192, 403-453.
• Wilson, C.T.R., 1906: On the measurement of the earth-air current and on the origin of atmospheric electricity, Proc. Camb. Philos. Soc., 13, 363-382.
• Wilson, C.T.R., 1911: On a method of making visible the paths of ionising particles through a gas, Proc. Roy. Soc. Lond. A, 85, 285-288.
• Wilson, C.T.R., 1912: On an expansion apparatus for making visible the tracks of ionising particles in gases and some results obtained by its use, Proc. Roy. Soc. Lond. A, 87, 277-292.
• Wilson, C.T.R., 1921: Investigations on lightning discharges and on the electric field of thunderstorms, Phil. Trans. Roy. Soc. Lond. A, 221, 73-115.
• Wilson, C.T.R., 1927: On the cloud method of making visible ions and the tracks of ionising particles, Nobel lecture, 12 December, 1927.
• Wilson, C.T.R., 1929: Some thundercloud problems, J. Franklin Inst., 208, 1-12.
• Wilson, C.T.R., 1956: A theory of thunderstorm electricity, Proc. Roy. Soc. Lond. A, 236, 297-317.
• Wilson, C.T.R., 1960: Reminiscences of my early years, Notes Rec. Roy. Soc. Lond., 14(2), 163-173.

Aston, Francis W. (1877 - 1945)

Francis Aston was a British chemist who invented the mass spectrometer. Modern measurements of atmospheric CO₂ concentration have been done by gas chromatograph and laser absorption techniques, but can also be done using mass spectrometers (Bender, M.L., Sowers, T., Barnola, J.-M., Chappellaz, J. Geophys. Res. Lett., 1994; 21: 189).

Aston's research was interrupted by WWI. During the war years he studied the effects of atmospheric conditions on the fabrics and dopes used in airplanes, as part of the war effort.

He won the Nobel Prize for chemistry in 1922.

Gökmen, Fatin (1877 - 1955)

Fatin Gökmen was a Turkish mathematician and astronomer. From 1904 to 1910, he was professor of Astronomy and Mathematics at the University of Istanbul.

The Imperial Meteorological Observatory had been established in 1868 but was destroyed in the uprising of March 1909. The new government formed after the uprising appointed Gökmen director of the Imperial Observatory and charged him with finding a location for a new building. He established the new Observatory, named Kandilli, in 1911. A class 1 meteorological observing station was set up there, and from 1 July 1911 continuous weather observations were made and recorded there. Also from that time, daily weather forecasts for Istanbul were prepared at the Observatory. Magnetic observations were introduced by Gökmen in 1927. The modern Observatory has maintained its meteorological function, but other geophysical and astronomical areas of study have been added to its responsibilities over the years, including, most recently, the study of earthquakes.

Terada, Torahiko (1878 - 1935)

Torahiko Terada was a Japanese meteorologist and university professor. He established the Earth Sciences Department at Tokyo University, where he taught meteorology. One of his students was Sakuhei Fujiwara, who became well-known for his research on what came to be called the "Fujiwara effect" in tropical cyclones.

du Toit, Alexander Logie (1878 - 1948)

Alexander Du Toit was a South African geologist who was one of the strongest early supporters of Wegener's theory of continental drift. Du Toit's arguments were mostly geological, but he also was intrigued by the observations that some fossils from tropical plants had been found in Antarctica, and glacial deposits had been found in Africa. Like Wegener, du Toit realized that historical climate change could be explained if the continents had drifted from one climatic zone to another, and furthermore that a rearrangement of the Earth's continents and oceans could act to change climate patterns.

In his 1937 work Our Wandering Continents: A Hypothesis of Continental Drifting, du Toit expressed these climate-related ideas: he stated that different continents could show "in their fossil remains common or allied forms of terrestrial life, possessed during certain epochs of climates that may have ranged from glacial to torrid or pluvial to arid, though contrary to meteorological principles when their existing geographic positions are considered".

Simpson, Sir George Clarke (1878 - 1965)

Simpson was an English meteorologist. He studied atmospheric electricity in Lapland in 1902 and was appointed meteorological lecturer at Manchester University in 1905. He became the Imperial Meteorologist for the Indian Meteorological Service in 1906, where his responsibilities included inspecting meteorological observing stations in India and Burma. In 1910 he joined Robert Scott's second Antarctic expedition (the British Antarctic Expedition) as expedition meteorologist. He served aboard the ship Terra Nova as it made its way to Antarctica. In Antarctica, he was responsible for one of the continent's first weather observing stations, at the Cape Evans base camp. A knoll just behind the Cape Evans hut, 66 feet above sea level, was named Wind Vane Hill. A run-of-the-wind anemometer and a Stevenson screen were set up on the knoll. Electric wires connected the anemometer cups to a recorder in the hut. The cup rotations were electrically counted; with every four miles of wind a signal sent to the hut caused a pen on a chronograph to register a step. The screen was visited (generally by Simpson) at 0800 each morning, in all weather, and the thermometers (maximum, minimum and present) were read. This BAT stamp shows Simpson standing in front of the screen and recording those temperatures. Furthermore, Simpson made the first Antarctic upper-air measurements using instrumented balloons. This document describes in some detail those measurements. This stamp shows expedition members, including Simpson, launching a weather balloon. Simpson also studied the local meteorological effects of the area. For example, he established that Minna Bluff acts to divide the airflow into two separate currents, which results in the cold and foggy "windless bight" area on the south coast of Ross Island.

Simpson returned to the Indian Meteorological Service early in 1912. There he compiled his notes about Antarctic meteorology. In 1919 he published the first volume of the expedition's meteorological records, entitled British Antarctic Expedition 1910-1913. Meteorology. Two other volumes followed.

Simpson was drafted into WWI military service and served in 1916 as meteorological advisor to the British Expeditionary Force in Mesopotamia. In 1920 he became the Director of the British Meteorological Office in London, where he conducted research into atmospheric electricity, ionization, lightning, radioactivity and solar radiation. In 1926 he established a wind force scale known as the Simpson scale, a modification of the Beaufort wind force scale.

Simpson retired from the Meteorological Office in 1938 but was recalled into active service in 1939 because of WWII. He was appointed head of the Kew Observatory, where he continued to study the electrical structure of thunderstorms until 1947. He served as president of the British Meteorological Society from 1940 to 1942.

Milanković, Milutin (1879 - 1958)

Milutin Milanković was a Serbian engineeer and mathematician who was intrigued by the ice ages and the climatic changes that must have caused the advance and retreat of the glaciers. His general ideas about this question followed those of the Scot James Croll, who in 1864 had published a paper in the Philosophical Magazine that hypothesized that variations in the Earth's orbit might have caused the ice ages.

In the WWI years Milanković studied the interactions between solar radiation and the temperature of the Earth. His results were published in Paris in 1920 in a monograph entitled Théorie mathématique des phénomènes thermiques produits par la radiation solaire (Mathematical theory of thermal phenomena caused by solar radiation). In it, he presented a curve describing the solar insolation at the Earth's surface. Köppen and Wegener used it in their 1924 work Klimate der geologischen Vorzeit (Climates of the Geological Past). In 1927 they invited Milanković to collaborate with them on their Handbuch der Klimatologie (Handbook on Climatology). He wrote the introduction to the Handbook: Mathematische Klimalehre und astronomische Theorie der Klimaschwankungen (Mathematical science of climate and astronomical theory of the variations of the climate). The ideas contained therein would form the basis of a theory that he formulated in the 1930s. That theory, which came to be known by the name of "Milanković cycles", presents a relationship between long-term cycles in the Earth's climate and changes in its orbital eccentricity, axial tilt and precession. The precession changes slightly in an approximate 26,000 year cycle. The Earth's orbit about the sun changes in 100,000 year and 400,000 year cycles. The tilt of the Earth's axis changes in a cycle of about 41,000 years. Milanković derived the mathematical formulas that describe these cycles and showed how they can interact so that at some times there is more sunlight striking the Earth, and at others there is less. When there is less, snow and ice can accumulate and glaciers can advance, forming an Ice Age. When there is more, there is warming and the ice retreats. Milanković presented the complete theory in his 1941 work Kanon der Erdbestrahlung und seine Anwendung auf das Eiszeitenproblem (A Study of Insolation reaching the Earth and its Application to the Problem of the Ice Ages).

The theory of Milanković cycles remained controversial, but a paper published in the journal Science in 1976 ("Variations in the Earth's orbit: pacemaker of the Ice Ages" by Hayes, Imbrie and Shackleton) confirmed the basic ideas. In it, measurements from deep ocean sediment cores along with new understanding of celestial mechanics were used to show that variations in solar insolation were the main cause of the advance and retreat of ice sheets in the Quaternary period.

Wegener, Alfred (1880 - 1930)

Alfred Wegener was a German geophysicist, Arctic explorer and meteorologist who advanced the theory of continental drift.

Wegener received a doctorate in astronomy in 1904, but found that he was more interested in geophysics, meteorology and climatology. At that time the telegraph, Atlantic cable and wireless were beginning to supply the data necessary for analysis and forecasting of storms. In 1905 he went to work at the Royal Prussian Aeronautical Observatory near Berlin, where he studied the atmosphere with kites and balloons. He was then invited to join a 1906 Danish expedition to Greenland's northeast coast. This was a dream come true for Wegener. In Greenland from 1906 to 1908 Wegener became the first person to use kites and tethered balloons to study the polar atmosphere. From 1909, he lectured on meteorology and astronomy at the University of Marberg. In 1911 he collected his meteorology lectures into a book, Thermodynamik der Atmosphäre (The Thermodynamics of the Atmosphere), which became a standard text in Germany.

Wegener also worked in the area of cloud and precipitation physics. As early as 1784, Benjamin Franklin had speculated that rainfall at the ground began as some form of snow in the clouds. Wegener considered that water can exist in the atmosphere in supercooled liquid form (at a temperature below 0°C), and also that the saturation vapour pressure over liquid water is greater than that over ice. He concluded that as a result, cloud ice crystals would necessarily grow at the expense of supercooled liquid cloud droplets. The resulting large ice crystals would be Franklin's 'snow', which could melt to form raindrops as it fell. These ideas were contained in Thermodynamik der Atmosphäre. Wegener never got the chance to document this process in real clouds, but Tor Bergeron and Walter Findeisen proved the theory in the 1930s. The process, often now known as the Bergeron-Findeisen process, is more correctly referred to as the Wegener-Bergeron-Findeisen process.

Wegener went back to Greenland in 1912-13 and crossed the Greenland ice cap with Danish explorer J.P. Koch and two others in a trip from Dove Bay on the east coast to Upernavik on the west coast. The data that he gathered during this journey made him one of the world's leading experts on polar meteorology and glaciology. According to fellow meteorologist and Greenland explorer Dr. Johannes Georgi, "Wegener was the first to trace storm tracks over the Greenland ice cap". He continued to work at Marburg until 1919, when he was appointed head of the Departement of theoretical meteorology at the German Hydrographic Office (The Deutsche Seewarte) in Hamburg. In 1924 he was appointed professor of Meteorology and Geophysics at the Institute of Physics, University of Graz. In addition to his continuing interest in continental drift and polar meteorology, he also conducted investigations concerning processes in the upper atmosphere and the aurora borealis. Furthermore, he also studied optical effects in the frigid air above the Greenland ice cap, where spectacular optical phenomena can occur in the presence of ice crystals. In a 1926 article, Wegener explained the formation process of two rare arcs that can appear opposite the sun in the presence of ice crystals. The arcs were then named in his honour.

In addition to his meteorological work, Wegener originated a revolution in geophysics: the idea of continental drift. This theory accounted for geological and fossil evidence that ancient climates had been vastly different from modern ones. Wegener thought that actual motion of continents might explain this climatic puzzle, so he and the climatologist Wladimir Köppen (who was also his father-in-law) plotted ancient deserts, jungles and ice sheets on paleogeographic maps based on the theory. The result was a plausible picture of past climates. Evidence of an ice age from some 280 million years ago, for example, scattered over almost all the Earth in modern times, clustered neatly around the South Pole in Wegener's map. This was because Africa, Antarctica, Australia and India had once comprised a southern hemispheric supercontinent (Gondwanaland). Wegener considered such paleoclimatic validation one of the strongest proofs of his theory. Conversely, continental drift has since become one of the main supporting principles of paleoclimatology. The South African geologist Alexander du Toit, working more or less independently, reached similar conclusions to those of Wegener and so became one of the early supporters of his theory.

Wegener returned to Greenland in the spring of 1930 as the leader of an expedition designed to systematically study the Greenland ice cap and its climate. Ernst Sorge, Johannes Giorgi and Fritz Lowe were part of this team. During this expedition, three research stations were set up: West camp, East camp, and Eismitte (Middle Ice camp, located on the ice cap at some 3000 m elevation). Unfortunately, in November 1930 Wegener and Rasmus Villumsen died while trying to reach West camp from Eismitte. Wegener was only 50. Despite his death, the expedition succeeded in its goal of recording one full year of meteorological observations at the Eismitte station as well as at the West camp station.

Germany's Alfred Wegener Institute for Polar and Marine research, established in 1980, was named in honour of Wegener.

Other selected publications by Wegener:

• Durch die weiße Wüste (The Crossing of the Ice Cap, 1912-13) (1919)
• The Origin of Continents and Oceans (published in German in 1912 and 1915, and translated to other languages in 1922)
• Die Klimate der Geologischen Vorzeit (The Climates of the Geological Past) (with W. Köppen, 1924).

Regener, Erich (1881 - 1955)

Erich Regener was a German physicist and professor of physics at Berlin and Stuttgart. He was also the director of the early Max Planck Institute for Stratospheric Physics in the years between the two World Wars (this Institute is now known as the Institute for Aeronomy). His research with upper air balloons launched from the Institute helped to define the chemical composition of the troposphere and the stratosphere. One particular area of interest for Regener was the influence of ultraviolet (UV) light on the chemical equilibrium between molecular oxygen (O₂) and ozone (O₃). In 1934 he became the first scientist to directly measure the absorption of UV energy in the ozone layer. He was therefore an important precursor in studies of the ozone layer. He also studied cosmic rays in the stratosphere.

Langmuir, Irving (1881 - 1957)

Irving Langmuir was an American physical chemist who spent much of his career with the General Electric (GE) corporation. He was awarded the Nobel prize for chemistry in 1932, but is remembered by meteorologists mostly for his pioneering work in the area of weather modification through cloud seeding.

He invented the Langmuir probe, an instrument designed to measure the properties of ionized gases (known as 'plasma', a term that he coined in 1927) in the upper atmosphere. In 1946, a Langmuir probe and other instruments were carried aloft from White Sands Missile Range by a V2 rocket. Although the V2 failed, the launch marked the first attempt to explore the upper atmosphere through direct measurements by rocket-borne instruments.

Langmuir had a strong interest in meteorology, particularly in the area of cloud microphysics. In the war years, he was involved in research on smoke screens and on aircraft de-icing capabilities. He and his colleague Vincent Schaefer invented the artificial fog smoke screen generator widely used during WWII. This work led him to think about clouds in general, and airborne particulates and ice nucleation in particular. In 1946, Langmuir and Schaefer realized that clouds might be modified by "seeding" them with dry ice pellets. The dry ice supplied to the cloud would form extra ice particles to which cloud water would migrate, resulting in more cloud droplets and potentially more rain. They demonstrated the effect later that year. Their work continued in the post-war years with dry ice and also silver iodide as seeding agents. The hope was that a certain amount of seeding could induce clouds to produce rain, while overseeding could potentially reduce hail and so reduce hail damage to crops. The work was controversial, and considerations of possible financial liability led GE to turn the program over to the military in 1947. The military continued to conduct cloud seeding experiments, some of which were carried out in the area of Socorro, New Mexico, which since 1963 has been home to the Irving Langmuir Laboratory for Atmospheric Research.

von Kármán, Teodor (1881 - 1963)

Teodor Von Kármán was a Hungarian fluid dynamicist and aerodynamicist whose work has some applications to the atmosphere. He emigrated to the US in 1930. In the period 1915 - 1938, von Kármán and Prandtl developed mixing-length hypotheses for the atmosphere, using eddy diffusivities and flux-gradient concepts based on analogies with molecular transfer (Garratt, J. R., 1992. The Atmospheric Boundary Layer, p.3-4. Cambridge University Press, 1992).

The von Kármán constant is used in studies of turbulence in the planetary boundary layer. Von Kármán "cloud streets" can occur in some cases in the low levels of the atmosphere downstream of an island or other low barrier across which a moderate wind is blowing. These atmospheric flow patterns may be visible in the low level cloud formations downstream of the barrier. If there is no obscuring middle or upper-level cloud, satellite imagery can clearly show them. Here is an example.

Von Kármán was the recipient of many awards, including, in 1963, the first US Medal of Science, which he received from John F. Kennedy.

Goddard, Robert H. (1882 - 1945)

Robert Goddard was an American physicist, engineer and rocketry pioneer whose work created the foundations of space flight. He is now considered to be the "father" of modern rocketry.

In 1919 he published his classic work, A Method of Reaching Extreme Altitudes, in which he showed that rockets could be used to explore the upper atmosphere, and that an object that would attain an "escape velocity" of about 11.2 km/sec could actually escape the Earth's gravity completely and head into space. However, he was ridiculed for this idea and so in later work generally avoided speaking of space flight. Instead, he tended to speak of his work in terms of high altitude research.

In 1926 Goddard launched the first liquid fuel rocket. In 1929 he launched the first instrumented rocket, carrying a barometer, a thermometer and a small camera (to record the readings of the instruments). Since that humble beginning, many instrumented rockets have been used for atmospheric research.

In 1963 the Goddard Space Flight Center (GSFC) was formed, honouring Goddard with its name. The Center's Laboratory for Atmospheres had as its mission to study the Earth's atmosphere through the use of satellite remote sensing techniques.

In 1970 the astronomical satellite OAO-B was named "Goddard" to honour his accomplishments. Unfortunately, the launch of OAO-B failed.

A well-known photo of Goddard shows him standing beside the frame that supported his first liquid-propelled rocket in 1926. Many philatelic items reproduce this photo in their designs. A few others have a similar design but with Goddard in a different position beside the frame. We consider all such items depicting Goddard standing beside the frame as "common design" items, and they are highlighted in pale yellow in the table below.

Potocnik, Hermann (1882 - 1929)

Hermann Potocnik was an Austrian astronautics pioneer (through his birthplace was in what is now Croatia). After serving in WWI, he graduated from the electrical engineering faculty of the Vienna Technology University. As part of his work in astronautics, he was the first to establish the scientific basis of the geostationary orbit. Satellites in such an orbit, at 36,000 km above the equator, remain constantly above the same spot on the Earth's surface, since they revolve around the Earth in the same time as the Earth takes to make one rotation on its axis. Many communications and weather satellites take advantage of this type of orbit.

Hess, Victor Franz (1883 - 1964)

Victor Hess was an Austrian physicist who did work in the area of atmospheric electricity.

In balloon flights in 1910, Alfred Gockel estimated the electrical conductivity of the atmosphere as a function of height by measuring the rate of charge leakage from an insulated Wulf electrometer, in ascents to as high as 4500 m. The leakage rate was found to be greater aloft than near the Earth's surface, which meant that the atmospheric ionization was greater aloft than near the surface. This was unexpected because at that time the ionization was thought to be greatest at ground level, due to local radioactivity of the soil. Gockel had no explanation for his observations, but they would turn out to be a precursor of the discovery of cosmic radiation in the atmosphere. In 10 balloon ascents made from 1911 to 1913, Hess repeated the measurements and showed clearly that the ionization reached a minimum at 800 m and then increased steadily up to the highest altitude which he reached. He explained this in terms of a penetrating radiation entering the atmosphere from outside but not from the Sun. This was eventually recognized as the discovery of what came to be called cosmic radiation, for which Hess would share the Nobel Prize in physics in 1936. He also founded a research station at Hafelekar mountain (at 2300 m) near Innsbruck for observing and studying cosmic rays.

Cosmic rays are hypothesized to have some influence on weather and climate. For example, the ionization due to cosmic rays can change the atmospheric electric field. Lightning (and the associated thunder) will occur if the electric field becomes large enough.

In a paper published in 1997, Henrik Svensmark and Eigil Friis-Christensen of the Danish Meteorological Institute in Copenhagen found a correlation between cloudy days and high cosmic ray concentrations. A possible causal mechanism was described by Fangqun Yu (State University of New York at Albany): cosmic ray energy encourages the formation of atmospheric aerosols which act as cloud condensation nuclei which are necessary for cloud droplets to grow, and therefore for clouds to form. This idea is still considered speculative, however.

Cosmic rays are at the basis of carbon-14 (¹⁴C) dating, since their energy acts to form the carbon-14 in the first place. Relative ¹⁴C amounts have been measured in materials for which the age is also known by some other means (e.g. using the rings in tree trunks). This is useful because one can then deduce the amount of ¹⁴C that was present in the atmosphere at that time in the past. This in turn gives a history of the ¹⁴C flux. Other proxy paleontological measurements can give some idea of the global historical weather at that time. The cosmic ray flux and the weather can then be compared, and it turns out that there is a correlation between the flux and the weather: when the weather was generally cold, cosmic ray fluxes were high, and vice-versa. If colder weather can be related to greater cloudiness (due to less solar radiation reaching the Earth's surface), then this framework is consistent with the work mentioned in the previous paragraph.

Another possible use of cosmic rays is in the measurement of soil moisture. A project being conducted by the University of Arizona called COSMOS (COsmic ray Soil Moisture Observing System) will study the low energy neutrons produced when cosmic rays strike the soil. Some of them are absorbed by the soil, while others are reflected back into space. It turns out that the number of neutrons in the air above the soil surface is inversely related to the soil moisture. Soil moisture can have a significant effect on weather, so improved measurement of soil moisture could lead to improved short term and longer term weather forecasts.

Hess's publications relating to the atmosphere include:

1. Elektrische Leitfähigkeit der Atmosphäre und ihre Ursachen (book), 1926 (The Electrical Conductivity of the Atmosphere and Its Causes, 1928);
2. Ionenbilanz der Atmosphäre (The ionization balance of the atmosphere - book), 1933;
3. Luftelektrizität (Electricity of the air - book, with H. Benndorf), 1928; and
4. Lebensdauer der Ionen in der Atmosphäre (Average life of the ions in the atmosphere), 1927-1928;

Piccard, Auguste (1884 - 1962)

Auguste Piccard was a Swiss physicist and aeronaut who explored both the heights of the atmosphere and the depths of the ocean. He and his twin brother Jean were pioneers in the balloon exploration of the stratosphere. Scientific balloon ascents in the 19th and early 20th centuries had been done in an open nacelle, but in the 1920s the Piccards developed pressurized nacelles and new high-altitude balloons. On 27 May 1931, with his colleague Paul Kipfer, Auguste Piccard lifted off from Augsberg, Germany in the balloon FNRS and made the first manned balloon flight into the stratosphere, reaching a record altitude of about 15.8 km. On 18 August 1932, Piccard and Max Cosyns went even higher (approximately 16.2 km). During his flights, Piccard made measurements of cosmic rays in the stratosphere and also recorded stratospheric temperatures. Other aeronauts followed Piccard's lead in exploring the stratosphere by balloon, including Jean Piccard and the Americans Albert Stevens and Orville Anderson.

Following his work with stratospheric balloons, Auguste Piccard turned his interest to the exploration of the ocean depths. As a boy he had dreamed about pressurized gondolas that could be used underwater, and eventually realized that a bathyscaphe could be thought of as an underwater balloon that uses gasoline for lift, since gasoline is lighter than water, just as hydrogen and helium provide the necessary lift for atmospheric balloons because they are lighter than air. It is in this sense that he later wrote in his book Earth, Sea and Sky that "it was the submarine that led me to the stratosphere".

In the latter half of the 1930s and in the 1940s Jean Piccard worked to improve the materials used in high altitude balloons. Polyethylene eventually became the balloon fabric of choice. It was light, not too expensive, and allowed balloons to ascend to around 30 km, where scientific measurements could be made with almost no atmospheric interference. Instruments aboard high altitude balloons have since studied ozone, carbon dioxide, carbon-14, nitrous oxide, nitrogen, dust particles, solar energy, cosmic rays and radiation in the high atmosphere. Eventually James van Allen would launch scientific rockets from high altitude balloons to get atmospheric measurements from even higher levels. All this work was possible in part as a result of the scientific legacy of the Piccard brothers.

¹ This WERABA-76 (exhibitiion) cinderella (vignette) contains reproductions of Switzerland 496, United States 1556, and Russia 4044

Piccard, Jean (1884 - 1963)

Jean Piccard was a Swiss engineer and aeronaut who became a US citizen in 1931. He and his twin brother Auguste were pioneers in the balloon exploration of the stratosphere. Scientific balloon ascents in the 19th and early 20th centuries had been done in an open nacelle, but in the 1920s the Piccards developed pressurized nacelles and new high-altitude balloons. In Germany in May 1931, Auguste Piccard and Paul Kipfer in the balloon FNRS became the first men to rise into the stratosphere. Meanwhile, in the US Jean Piccard was the leader of the team that was working with the Century of Progress stratospheric balloon. It included the Nobel laureates Arthur Compton and Robert Millikan. Lt Commander T.G.W. Settle of the US Navy was the pilot. After an aborted demonstration flight at the Chicago World's Fair in August 1933, the team conducted a successful scientific flight in November of that year. During that flight, which reached an altitude of 18.6 km, various scientific measurements were conducted in the stratosphere. The balloon carried instruments to measure cosmic rays, a polariscope to measure the polarization of light at high altitudes, equipment to take air samples and an infrared camera and spectrograph to study ozone. Nearly a year later, on 23 October 1934, Jean Piccard and his wife Jeannette made what turned out to be the last flight of the Century of Progress. They reached an altitude of 17.5 km.

In the latter half of the 1930s and in the 1940s Jean Piccard worked to improve the materials used in high altitude balloons. Polyethylene eventually became the balloon fabric of choice. It was light, not too expensive, and allowed balloons to ascend to around 30 km, where scientific measurements could be made with almost no atmospheric interference. Instruments aboard high altitude balloons have since studied ozone, carbon dioxide, carbon-14, nitrous oxide, nitrogen, dust particles, solar energy, cosmic rays and radiation in the high atmosphere. Eventually James van Allen would launch scientific rockets from high altitude balloons to get atmospheric measurements from even higher levels. All this work was possible in part as a result of the scientific legacy of the Piccard brothers.

Zubov, Nikolai Nikolaevich (1885 - 1960)

Nikolai Zubov was a Soviet oceanographer who founded the department of oceanography at the Moscow Hydrometeorological Institute in 1932, and was its director from 1932 to 1941. He did original work on ice forecasting in the Arctic Ocean, and studied how the atmospheric pressure pattern influences sea ice movement.

Zubov was in charge of the scientific programme of the ship Sadko expedition, which sailed from Arkhangelsk on 8 July 1935 to explore the western part of the Soviet Antarctic Ocean and the Greenland Sea. Its proposed areas of scientific investigation included meteorology, sea ice, marine biology, physical oceanography and the investigation of seabed sediments. The bulk of the work carried out was oceanographic, but ice observations and meteorological observations were also made, and up to three synoptic weather analyses were made daily.

In total in 85 days the Sadko steamed 12,000 km. A total of 21 meteorological radiosondes were released, and 280 meteorological observations were made (of which 263 were transmitted back to the mainland). The meteorological and ice data collected would be important in forecasting conditions along the Northern Sea Route for shipping in the years following the Sadko expedition.

Priestley, Raymond (1886 - 1974)

Raymond Priestley was a British geologist and Antarctic explorer. After WWI, he held various academic and administrative posts in Australia and England. While he was vice-Chancellor of the University of Melbourne in the 1930s, he became involved with the university's Meteorology Section, and in 1937 arranged that Carnegie Foundation funds be used to bring meteorologist Fritz Loewe to Melbourne to take up the appointment of Reader in charge of the Section. (Loewe had accompanied Alfred Wegener on his last Greenland expeditions. While in Greenland, Loewe and Ernst Sorge made the first seismic measurments that demonstrated that the ice cap was surprisingly thick, even close to its margin). Loewe established the Department of Meteorology at the University of Melbourne in 1939.

Priestley served as head of the Royal Geographic Society from 1961 to 1963.

Stevens, Capt. Albert W. (1886-1949) Anderson, Capt. Orville A. (ca 1890? - ?)

Captains Albert Stevens and Orville Anderson of the US Army Air Corps were military aeronauts who made stratospheric balloon flights soon after the pioneering stratospheric work of Auguste Piccard and Jean Piccard. Scientific observations were an important part of the ascents made by Stevens and Anderson. On 28 July 1934 in the Explorer-I hydrogen balloon they reached 18.3 km, but at that point the balloon exploded, forcing the crew to parachute to safety. On 11 November 1935, in a mission sponsored by the National Geographic Society, they flew the Explorer-II helium balloon to an altitude of 22 km above South Dakota. This was a record that would stand for 21 years. During the flight, measurements were made of the temperature and pressure, the chemical composition of the air, the vertical distribution of the concentration of ozone, and the intensity of cosmic rays. Data on the propagation of radio waves in the high atmosphere were also collected. Stevens and Anderson also brought back the first colour photographs ever taken from the stratosphere. They showed the land below, the curvature of the Earth and the visual division between the troposphere and the stratosphere. Careful measurements of the balloon's altitude were made using photographs of terrain and angular measurements from the ground. The vertical distributions of air pressure and temperature were also carefully recorded. After the flight, those data were used to calculate the balloon's altitude through the use of the meteorological hydrostatic equation (a relationship involving pressure, temperature and height above the ground). The heights thus calculated were then compared with the other, independent measurements of altitude to verify the accuracy of the hydrostatic equation. Stevens and Anderson were awarded the National Geographic Society's Hubbard Gold Medal for their work on this mission.

Vize, V. U. (1886 - 1954)

V. U. Vize was a Russian meteorologist, oceanographer and polar explorer, and a member of the Soviet Academy of Sciences. He participated in many Soviet Arctic expeditions, including the voyage of the icebreaker Sibiryakov in 1932. Under the leadership of Otto Schmidt, that expedition, undertaken as part of the Soviet work for the 2nd IPY (International Polar Year), marked the first time that a ship was able to travel the entire Northeast Passage from west to east in a single season. Vize was also aboard the icebreaker Litke in 1934, which in that year became the first ship to transit the Northeast Passage from east to west in a single season. These voyages were important building blocks in the establishment of the Soviet Northern Sea Route. In particular, from 1933 to 1935 the General Directorate of the Northern Sea Route, under Schmidt, not only improved navigation services and built new Arctic ports, but also increased the number of polar hydrometeorological stations and radio transmitting stations from 16 to 51.

Throughout his career, Vize published works on oceanography, meteorology and the history of Arctic exploration.

Fridman, Alexander Alexandrovich (1888 - 1925)

Alexander Fridman was a Russian meteorologist. In February 1913 he was appointed to a position in the Aerological Observatory in Pavlovsk (a suburb of St. Petersburg), where he studied meteorology and made aerological observations. In 1914 he studied dynamic meteorology under the Norwegian Vilhelm Bjerknes, the leading theoretical meteorologist of the time. After 1914, Fridman took part in several flights in airships to make weather observations. Thereafter he continued to work in various scientific disciplines, including meteorology, aeronautics and mechanics. In July 1925 he made a record-breaking ascent in a balloon to 7400 metres altitude to make meteorological and medical observations.

Byrd, Richard E. (1888 - 1957)

Richard Byrd was an American military aviator and polar explorer. After a flight to the North Pole in 1926 and another across the Atlantic in 1927, he turned his sights to the Antarctic, which he would visit five times during the course of his career. His first Antarctic expedition took place from late 1928 through early 1930. His goals for were:

1. to add to the scientific knowledge of Antarctica, particularly in the areas of meteorology, geography, geology and geomagnetism;
2. to explore the interior plateau; and
3. to fly over the South Pole.

Byrd succeeded in all of these objectives (the South Pole flight took place on 29 November 1929).

Byrd returned to Antarctica in early 1934, again with scientific research as his primary goal. Drawing partly on the scientific experience of researchers who had participated in the Antarctic work of the 2nd IPY (International Polar Year) of 1932-33, Byrd and his team, based at Little America, began a program of survey and mapping flights and geological, biological and meteorological research, including regular weather observations. Byrd himself wanted to make meteorological observations away from the coast, and spent the winter at a camp some 120 miles south of Little America on the Ross Ice Shelf. Known as the Bolling Advance Weather Station, it was a fully-equipped weather observing site, and Byrd's observations were the first ever made in winter at an Antarctic inland station. Byrd was alone at the station starting March 28, and later nearly perished from carbon monoxide poisoning. A rescue team of three arrived at Bolling on 11 August. The four men together then completed the winter observing program and finally abandoned the station on 14 October 1934.

Byrd later wrote a book titled Alone in which he described his sojourn at Bolling. He wrote that his decision to occupy the station alone was in part personal: "beyond the solid worth of weather and auroral observations in the hitherto unoccupied interior of Antarctica and my interest in these studies, I really wanted to go for the experience's sake".

In Alone, Byrd described the observing instruments at his disposal at Bolling, and the observing schedule:

"I was not long in discovering one thing: that, if anything was eventually to regularize the rhythm by which I should live at Advance Base, it would not be the weather so much as the weather instruments themselves. I had eight in continuous operation. One was the register, already described, which kept a continuous record of wind velocities and directions. The electrical circuit, connecting with the weather vane and wind cups on the anemometer pole topside, was powered by nine dry cell batteries; and the brass drum with the recording sheet was turned by a clock-work mechanism which I had to wind daily. The sheet was lined at intervals corresponding to five minutes in time; and between these lines two pens, one representing the speed of the wind and the other its direction, wrote steadily from noon of one day to noon of the next.

Two other instruments were thermographs, which recorded temperature changes. The so-called inside thermograph was a fairly new invention, whose unique virtue was that it could be housed inside the shack. A metal tube filled with alcohol projected through the roof, and the expansions and contractions of the liquid in the tube drove a pen up and down over a rotating sheet set in a clock-faced dial hanging from the wall, just over the emergency radio set. The sheet, marked with twenty-four spokes for the hours and with concentric circles for the degrees of temperature, made one rotation in twenty-four hours; it would record accurately down to 85 degrees below zero. The outside thermograph was a compact little mechanism which served the same function, except that it stood in the instrument shelter topside and the sheets needed changing only once a week.

Besides these instruments, I had a barograph to record atmospheric pressure, which was kept in a leather case in the food tunnel. Plus a hygrometer employing a human hair, for measuring humidity (not very reliable, though, at cold temperatures). Plus a minimum thermometer, which measured the lowest temperature. In it was a tiny pin which was dropped by the contraction of alcohol in the column. Alcohol was used instead of mercury because mercury freezes at -38 degrees whereas, pure grain alcohol will still flow at -179 degrees. This instrument was useful as a check on the thermographs. It was kept in the instrument shelter, a boxlike structure set on four legs, which stood shoulder high, close to the hatch. The sides were overlapping slats spaced an inch apart to allow air to circulate freely and yet keep out drift. If I had had any illusions as to being master in my own house, they were soon dispelled. The instruments were masters, not I; and the fact that I knew none too much about them only intensified my humility. There was scarcely an hour in the living day of which a part was not devoted to them or observations connected with them.

Every morning at 8 o'clock sharp, and again at 8 o'clock in the evening, I had to climb topside and note the minimum temperature reading, after which I would shake the thermometer hard to put the pin back into the fluid. Then, standing five minutes or so at the hatch, I would consult the sky, the horizon, and the Barrier, noting on a piece of scratch paper the percentage of cloudiness, the mistiness or clarity, the amount of drift, the direction and speed of the wind (a visual check on the register), and anything particularly interesting about the weather. All of these data were dutifully entered on Form No.1083, US Weather Bureau.

Every day, between 12 o'clock and 1 o'clock, I changed the recording sheets on the register and the inside thermograph. The pens and the pads supplying them always needed inking, and the thermograph clock had to be wound. Mondays I performed the same service for the outside thermograph and the barograph."

In another part of his book, Byrd describes some of the difficulties he encountered with instrument maintenance in the harsh Antarctic conditions:

"The wind vane has been giving quite a bit of trouble lately. I've had to climb the pole once or twice every day to scrape the contact points. The temperature is holding pretty steadily between 50 degrees and 60 degrees below zero; and I must admit that the job is chillier than I bargained for." … "Just when I was congratulating myself on having mastered the job of weather observer, the outside thermograph began to act up. A devilish contrivance, it occupied the instrument shelter topside, where hoarfrost settled on the trace, the pen, the drum, and even the workings. On the one occasion I brought the instrument into the shack to change the sheet and make an adjustment, the difference in temperature coated the metal with rime and stopped it dead. Thereafter I had no choice but to make the adjustments in the chill of the tunnel, with no protection for my hands except thin silk gloves; even those seemed infernally clumsy when I had to deal with the speed regulator, which must have been invented for the specific purpose of plaguing weather men."

As may be imagined, the winter temperatures at Bolling Advance Weather Station were generally bone-chilling. Byrd recorded that in May, there were 20 days colder than -40°F, 12 days colder than -50°F, three colder than -60°F and two colder than -70°F. However, warm temperatures did occur for brief periods: May 24 in particular was "unbelievably warm", with a maximum temperature of 18°F above zero. This was the result of maritime air making its way inland. July, closer to the middle of the austral winter, was brutal: there were 20 days colder than -60°F and six colder than minus 70°F! However, there was again a short mild period: on 27 July, the temperature reached nearly 0°F. The weather was very changeable: Byrd experienced weather that ran the gamut from calm and clear conditions to howling blizzards with zero visibility.

Wilkins, Sir Hubert (1888 - 1958)

Hubert Wilkins was an Australian polar explorer and adventurer. As a child, he experienced the effects of a severe drought and so became interested in weather and climate. As a young man, he learned to fly, and studied the climate, meteorology and sea ice of the polar regions. He learned how to survive in those regions, and put forth the idea of improving weather forecasting by establishing permanent stations at both Poles. In 1923 he became a fellow of the Royal Geographic Society and the Royal Meteorological Society. Also in the 1920s, he turned his attention more and more to the idea of polar exploration by air, and in April 1928 became the first person (with Carl Eielson as pilot) to fly across the Arctic from the New World to the Old. They flew in a Lockheed Vega monoplane from Point Barrow, Alaska to Spitzbergen. Wilkins closed out the 1920s with two trips to the Antarctic, where he did more aerial exploration.

In 1931 Wilkins tried to navigate a submarine (leased for $1 per year from the US) under the ice pack to the North Pole. He said that "… the expedition is for the purpose of gathering data in connection with a plan for comprehensive meteorology study, including the polar areas and with the hope that once polar meteorological study, including the polar areas and with the hope that once polar meteorological stations are established it will be possible to forecast for several years in advance, the seasonal conditions, and to collect scientific data of academic and economic interest from an area hitherto unapproached by a scientific staff equipped with a complete scientific laboratory and facility for comfortably carrying out their investigation and provided with adequate means of sustenance and means of safe retreat. Millions of dollars are spent each year by various institutions in oceanographic and geophysical research. A submarine will provide means for similar investigations in an economic and safe manner, in areas as yet untouched by scientists". The attempt failed because of multiple mechanical problems. Thereafter in the 1930s, Wilkins collaborated with Lincoln Ellsworth in his (Ellsworth's) aerial exploration of the Antarctic.

In WWII, Wilkins worked for the Quartermaster Corps of the US Army, where he studied clothing, rations and survival techniques for conditions of extreme cold. In the late 1940s, he served as an adviser to the US Weather Bureau.

Throughout his career, Wilkins received many honours including a knighthood, and was recognized by geographical and scientific societies for his work in geography, climatology and meteorology.

Väisälä, Vilho (1889 - 1969)

Väisälä was a Finnish physicist and meteorologist. He began a 36-year career with the Finnish Meteorological Institute in 1912. His first task was to make magnetic measurements in Finland. He then turned to upper-air meteorological measurements which were at the time made with instrumented kites. He was appointed head of the Ilmala kite station in 1916 and director of the aerological department in 1919. Väisälä had a flair for instrumentation and his department developed various upper-air measurement techniques and instruments, culminating in the Väisälä radiosonde (a small package of instruments carried aloft by a weather balloon). It was first flight-tested on 30 December, 1931 and was introduced to the international meteorological community in 1935. It was simple, reliable and moderately-priced. It soon became the standard in Scandinavia, and found broad international acceptance as well. It won a gold medal at the Exposition Internationale des Arts et Techniques dans la Vie Moderne in Paris in 1937.

The Russian meteorologist Pavel Molchanov independently developed radiosonde instrumentation at about the same time as Väisälä, and is credited with the launch of the first radiosonde at the Main Geophysical Observatory in Pavlovsk on 30 January 1930.

In 1936 Väisälä founded a private company to manufacture radiosondes. At first called Mittari Oy, its name was changed to Vaisala in 1955. Väisälä was its director until his death. As the company grew, its product line expanded to include other meteorological instruments. It is today a major provider of meteorological instrumentation, with clients in some 120 countries around the world.

Väisälä was appointed professor of meteorology at the University of Helsinki in 1948.

The Professor Vilho Väisälä Award was established in 1985 by the World Meteorological Organization to honor outstanding research involving meteorological observation methods and instruments.

Dobson, Gordon Miller Bourne (1889 - 1976)

Gordon Dobson was an English physicist and meteorologist. He took a position as University Lecturer in Meteorology at Oxford in 1920. There he studied meteor trails and with F. A. Lindemann deduced that there must exist a region above the tropopause in which the temperature increased substantially with height (this region is the stratosphere). Dobson then concluded that the warming of the stratosphere must be caused by the absorption of solar ultraviolet (UV) radiation by ozone. He proceeded to measure the ozone by observing its absorption in the solar UV spectrum following the technique of Fabry and Buisson. To this end he built his first spectrograph in 1924, and with a year had used it to demonstrate the main features of the seasonal variability of total column ozone and also the correlation between the ozone amount and the meteorological conditions in the upper troposphere and lower stratosphere. He continued this work through the late-1920s with more extensive measurements made by his instrument at locations throughout the world. Further development of his spectrograph led to the instrument that became known as the Dobson spectrophotometer, which became the international standard for ozone measurement. The units used to measure ozone came to be known as "Dobson Units" (DU). Modern measurements of total column ozone are still expressed in Dobson Units.

In 1926 Dobson presented the Halley lecture on "The uppermost regions of the Earth's atmosphere" in which he presented a summary diagram of those regions. A year later he was elected to a new Readership in Meteorology. In the 1930s he developed an interest in atmospheric pollution, and from 1934 to 1950 served as Chairman of the Atmospheric Pollution Committee of the Department of Scientific and Industrial Research, where he directed the development of methods to measure smoke, deposited particulate matter and sulphur dioxide.

In order to understand and forecast atmospheric conditions at levels where condensation trails from aircraft were occurring, Dobson and Alan Brewer studied stratospheric humidity during World War II. To make the necessary measurements, Brewer modified one of Dobson's hygrometers so that it would accurately measure the frost-point (rather than the dew point) when mounted in an airplane. Measurements with that hygrometer revealed that the stratosophere was extremely dry. Brewer hypothesized that the dry air could only have originated in the area of the equatorial tropopause, and postulated a circulation in which air enters the stratosphere in the equatorial area, moves poleward and exits the stratosphere at higher latitudes. Dobson and Brewer published some of these ideas in 1946. Brewer continued to develop the theory and in 1949 published the details of what came to be known as the "Brewer-Dobson circulation" in a seminal paper in the Quarterly Journal of the Royal Meteorological Society. The Brewer-Dobson circulation is generally accepted as the breakthrough in understanding why the stratosphere is so remarkably dry. Its details are still a subject of study to this day, world wide.

Those studies of humidity in turn led Dobson to examine the mechanism by which water drops freeze. He and his students built cloud chambers in which they could study the phenomenon, and showed that drops of pure water would not spontaneously freeze until a temperature of -40°C was reached, while drops that contained various impurities would freeze at warmer temperatures.

Dobson was awarded the Symons Gold Medal of the Royal Meteorological Society in 1938, and was the president of the Society from 1947 to 1949.

In the early 1950s Dobson and Brewer began to study how ozone would fit into the Brewer-Dobson circulation. In 1955 a version of Dobson's ozone-measuring spectrograph was mounted in an airplane, and Brewer operated it during four stratospheric flights at Tromsö, Norway. The measurements showed that there was a sharp transition to higher values of ozone concentration at the tropopause. This work was only part of ongoing ozone studies by both Dobson and Brewer which eventually did show that stratospheric ozone has a latitudinal dependence consistent with the Brewer-Dobson circulation.

In 1956 some 44 Dobson spectrophotometers were in operation throughout the world and many more were built and put into operation for the International Geophysical Year (IGY). Dobson continued his work on ozone until the end of his life. Brewer designed an updated instrument to replace the ageing Dobson spectrophotometer in the early 1970s. The new Brewer ozone spectrophotometer became the worldwide standard instrument for measuring total column ozone, but it still uses the basic principles of Dobson's instrument.

Here is a complete list of Dobson's scientific papers.

Armstrong, Edwin H. (1890 - 1954)

Edwin Armstrong was an American electrical engineer and inventor. Radio in the early 1920s operated on the AM (amplitude modulation) principle, in which the sound patterns were defined by varying (modulating) the amplitude (which is related to the power) of the carrier wave, at a fixed frequency. However, electrical storms and other atmospheric phenomena were known to distort the AM patterns and create interference and static. Armstrong wanted to eliminate these problems, and reasoned in the late 1920s that the carrier wave frequency should be modulated, with its amplitude remaining constant. He introduced this new FM (frequeny modulation) system in 1933, and tests showed that it provided clear reception even in the presence of violent thunderstorms.

Kezhen, Zhu (Coching Chu) (1890 - 1974)

Zhu Kezhen was a meteorologist and geographer who is considered to be the founder of modern meteorology in China. After studies in the USA (Ph.D. in meteorology from Harvard), he taught meteorology at schools in Wuhan, Nanjing, Shanghai and Tianjin. He was the chairman of the Department of Meteorology at Nanjing University from 1920 to 1929. In 1929 he became the director of the Chinese Meteorological Research Institute of the Central Academy. During his career he served as president of the Chinese Meteorological Society and the Chinese Geographical Society as well as several other scientific bodies. In 1934 Kezhen invited Chang Wang Tu to return to China from England to take up the post of researcher at the Institute of Meteorology at the Central Academy. Tu would later become the director of the Chinese Meteorological Bureau.

Kezhen specialized in climatology, and introduced the science of phenology (the study of periodic natural cycles related to climate, such as the migration of birds) to China, and established a Chinese phenological observing network in 1934. He was the author of a detailed study of the Chinese climate over the last 5000 years (A Study of Climate Changes in China over the Past Five Millenia) based on a temperature index that he created. Kezhen considered that the study of historical climate changes could be useful in forecasts of future climate changes. He published some 300 scientific papers in his areas of interest, which included the study of typhoons and monsoons. In addition to the climate study mentioned abouve, his major meteorological publications include Phenology; An Outline of Meteorology in China; The Interrelationship between Meteorology and Agriculture; A Few New Facts in the Centre of a Typhoon; A New Classification of Typhoons in the Far East; The Place of Origin and Recurvature of Typhoons; Movements of Air Currents in China; The Southeast Monsoon and Rainfall in China; Relations of Climate to Men and Other Lives; On the Characteristics of China's Climate and the Relations between those Characteristics and Food Production; China's Subtropical Zone; and A Preliminary Study of Climate Types of East Asia.

Another of Kezhen's interests was the history of science, and particularly the ancient scientific legacy of China.

Schmidt, Otto Yulievich (1891 - 1956)

Otto Schmidt was a Russian geophysicist, mathematician, polar explorer and member of the Russian Academy of Sciences. He was the head of several Arctic expeditions. The earliest of these was the Georgy Sedov expedition of 1929-1930, which established the first scientific research station, including a weather observatory, in Franz Josef Land (it was located on Tikhaya Bay on Hooker Island, and began operations in 1929. From 1930 to 1932 Schmidt was Director of the Arctic Institute (the precursor of the Arctic and Antarctic Research Institute (AARI) which would later be headed by A. F. Treshnikov). In 1932, as part of the Soviet contribution to the 2nd IPY (International Polar Year), Schmidt led an expedition aboard the icebreaker Sibiryakov. It sailed the whole Northeast Passage, from west (Archangelsk) to east (Bering Strait) in a single summer season. This was the first time the trip had ever been made without wintering en route. After this success, the General Directorate of the Northern Sea Route was established, with the goal of preparing the route for safe marine navigation. Schmidt was appointed as its Chief. Under his guidance, more trial runs were conducted in 1933 and 1934, and the route was officially opened and commercial exploitation began in 1935. This was possible partly because of improved infrastructure: from 1933 to 1935, Schmidt and the Directorate not only improved navigation services and built new Arctic ports, but also increased the number of polar hydrometeorological stations and radio transmitting stations from 16 to 51.

In the winter of 1933-1934, Schmidt led the disastrous expedition in which the icebreaker Chelyuskin was lost in the Chukchi Sea, crushed by the ice (E. T. Krenkel was also part of this expedition). In 1935 Schmidt headed the interagency Office of Ice Forecasting which combined oceanographic and meteorological information to produce ice forecasts for the Northern Sea Route. In that year he also became a member of the Academy of Sciences.

In 1937 Schmidt organized an airborne expedition that established a research station on the Arctic Ocean ice. It started at a point only about 20 km from the North Pole, and was known as the NP-1 (North Pole-1) drifting ice station. The four crewmembers of the station were Papanin, Fedorov, Krenkel and Shirshov. NP-1 provided regular weather observations which were sent by wireless back to the USSR. It was the first ever research station on the Arctic ice and during its lifetime drifted to a point off the northeastern Greenland coast. NP-1 opened a new stage in the history of Arctic research, in which more systematic scientific studies were possible than. The Soviet Union and Russia have operated a total of 37 such NP stations, generally with a scientific component that included meteorology.

Two hydrometeorological observatories have been named after Schmidt. One, in his home town of Mogilev (now in Belarus), is the Otto Schmidt Mogilev Regional Hydrometeorological Observatory. The other is the Cape Schmidt Hydrometeorological Observatory in eastern Siberia, on the Arctic coast to the south of Wrangell Island. The Institute of Earth Physics in Moscow was also named after Schmidt.

Appleton, Edward Victor (1892 - 1965)

Edward Appleton was an English physicist who studied the physics of the upper atmosphere.

Marconi's transatlantic wireless transmissions in 1910 had shown that there must exist an upper atmospheric layer from which radio waves are reflected back down to the surface. Gauss had hypothesized some 100 years earlier that such a layer must exist. Appleton in 1924 used a BBC radio transmitter to beam radio signals of varying wavelengths into the upper atmosphere. His analysis of the received signals allowed him to calculate that the height of the reflecting layer was about 100 km. The layer was named the 'ionosphere' by Watson-Watt in 1926. Appleton's technique is now known as 'frequency modulation radar', a precursor of modern forms of radar. The ionosphere was therefore the first 'object' detected by radiolocation. Watson-Watt would build on this work to develop the first workable radar system in the 1930s. This system allowed Britain to detect enemy aircraft during WWII. Radar techniques were also applied to meteorology: weather radar able to detect hydrometeors (liquid and/or solid precipitation) was developed, starting in the war years.

In 1926 Appleton discovered a higher layer (250 - 350 km) of the ionosphere that came to be called the Appleton layer. In the late 1920s and 1930s he and his colleagues used instruments known as 'vertical sounding ionosondes' to determine the properties of the various ionospheric layers. They provide records known as ionograms. An international network of ionosondes was later established for the International Geophysical Year (IGY), and continued to operate thereafter. Consisting of some 40 observing stations around the world, its observations allow forecasts of the most suitable wavelengths for worldwide radio communications to be made.

In 1929 Appleton continued his upper atmospheric research in northern Norway. While there he also studied the aurora borealis.

Using sunspot observations taken at the sunspot minimum in 1934 and the maximum in 1937, Appleton demonstrated that the ionization and therefore the reflective power of the ionosphere vary with sunspot activity.

Appleton noted that lightning affects radio reception, and therefore investigated the electric waves that are produced as a result of lightning discharges. He was able to use special sounding equipment that could locate lightning strikes (and therefore thunderstorms) at great distances. He hypothesized that thunderstorms as far away as the equatorial areas could cause disturbances that affect radio reception.

Appleton was awarded the Nobel Prize in physics in 1947 for his upper atmospheric research.

Watson-Watt, Robert Alexander (1892 - 1973)

Robert Watson-Watt was a Scottish physicist best known for the development of radar. He worked at the British Meteorological Office in 1917 on the radio detection of thunderstorms. This was an important project due to the hazard such storms posed to aviators, and was the basis for his later work on radio pulse techniques and radar.

Watson-Watt's work included consideration of the structure of the upper atmosphere and its effect on radio waves. Marconi's transatlantic wireless transmissions in 1910 had shown that there must exist an upper atmospheric layer from which radio waves are reflected back down to the surface. Gauss had hypothesized some 100 years earlier that such a layer must exist. Appleton in 1924 used a BBC radio transmitter to beam radio signals of varying wavelengths into the upper atmosphere. His analysis of the received signals allowed him to calculate that the height of the reflecting layer was about 100 km. Appleton's technique, now known as 'frequency modulation radar', was a precursor of modern forms of radar.

In 1926 Watson-Watt coined the term "ionosphere" for the reflecting layer and proposed it in a letter to the United Kingdom Radio Research Board. The term was adopted and came into common use some years later.

Watson-Watt developed a radio pulse technique in the 1920s and 30s that was based partially on Appleton's 'frequency modulation radar'. Watson-Watt was eventually able to locate aircraft through his radio pulse technique, and is credited with the development of the first workable radar system in the 1930s (radar is an acronym for RAdio Detection And Ranging). He was appointed Director of Radio Research at the British National Physical Laboratory in 1935. In 1942, he was knighted for his work on radar. His radar system allowed Britain to detect enemy aircraft during WWII. Radar techniques were also applied to meteorology: weather radar able to detect hydrometeors (liquid and/or solid precipitation) was developed, starting in the war years.

Molchanov, Pavel A. (1893 - 1941)

Pavel Molchanov was a Soviet meteorologist who worked at the Main Geophysical Observatory in Pavlovsk from 1917 to 1939. He was interested in applying aerological data (upper air data, measured in the atmosphere above the surface) to weather forecasting. He experimented with meteorographs that could be carried aloft by balloons, but they were complicated and had to be recovered before their recorded data could be examined. Molchanov's goal was to develop a cheap and reliable means of sounding the atmosphere for temperature, moisture and wind data. This goal was met through his development of the radiosonde, a balloon-borne instrument package that could transmit observations back to a receiving station by radio. Many philatelic examples of weather balloons and radiosondes are found here.

On 30 January 1930, he launched the first radiosonde from the Geophysical Observatory. It reached an altitude of 7.8 km and sent observed data in the first-ever upper air message to the Leningrad Weather Bureau and the Central Forecast Institute in Moscow. Molchanov's radiosondes were used in the Arctic as part of the USSR's contribution to the Second International Polar Year (IPY) in 1931. They provided the first upper-air observations ever made in the Arctic.

Mass production of Molchanov's radiosonde began in 1935. His design provided observations that were accurate and stable enough that it was used without any major changes until 1958.

The ship Professor Molchanov was named in his honour. It has served as an oceanographic research vessel and a polar cruise ship.

Demuyter, Ernest (1893 - 1963)

Ernest Demuyter was a Belgian Army lieutenant and balloon pilot who flew the balloon Belgica to victory in the Gordon Bennett balloon race in 1920, 1922, 1923, 1924, 1936 and 1937.

Early in his career Demuyter was employed as a meteorology instructor. This background stayed with him throughout his life as a balloonist.

Meteorology was not closely considered in hot air ballooning in the early 20th century. Speaking of the 1913 Gordon Bennett race, Demuyter noted that "meteorology in those days was in its childhood. Of course the pilots got handed out the information from all meteorological stations around the world, and often the forecast for beginning rain, snowfall or storm was true. But there were no weather maps as we know today from the television every evening. There was also no weather briefing before launch. Everybody got his own information. What he then concluded and how he put it to practice was his own affair". Demuyter was convinced that the best balloon pilots were those who were also meteorologists, or at least very familiar with meteorology. Those pilots could put meteorological information to good use. Demuyter was one of the first pilots to carefully consider the influence of meteorological conditions in his planning for balloon flights and competitions. For example, he pointed out that "every balloon pilot knows (or should know) that the wind turns right [i.e. clockwise] in a high pressure area and counter clockwise in a low. Today we [also] know the gradient winds, floating almost parallel to the isobars".

Ibarra, José María Velasco (1893 - 1979)

José Ibarra was an Ecuadorian politician who was president of the country on five separate occasions between 1934 and 1972. After the earliest meteorological observations made by de La Condamine in the 1730s, the science of meteorology developed gradually in Ecuador. The effects of El Niño episodes came to be studied, particularly after the devastating El Niño of 1925. At subsequent scientific conferences in Rio de Janeiro (1935) and Montevideo (1939) the importance of meteorology to South American states including Ecuador was emphasized, and resolutions were passed concerning national meteorological services. Ibarra knew the importance of state infrastructure and institutions and on 20 October 1944 complied with the resolutions and signed a presidential decree that established the Meteorological Service of the Astronomical Observatory of Quito. The Service developed over the years, and on 4 August 1961 Ibarra (he was again president) signed the executive decree that created Ecuador's National Institute of Meteorology and Hydrology (INAMHI). This allowed the country to join the modern international meteorological community.

Urey, Harold Clayton (1893 - 1981)

Urey was an American chemist who won the Nobel Prize for chemistry in 1934 for his studies of isotopes. During the 1940s while at the University of Chicago, his work with oxygen isotopes led him to hypothesize that the ¹⁸O/¹⁶O ratio in calcite (CaCO3) should vary as a function of the temperature at which the mineral had precipitated. He and his colleagues and students then measured that ratio over a wide range of temperatures and came up with an equation relating the ratios to temperatures. The equation can be considered as a "paleothermometer" since the ratios obtained from the calcite shells of fossilized foraminifera in lake or ocean sediments (sediment coring provides the necessary samples) can be used to estimate the paleotemperatures (the temperatures of the ancient times from which the shells came). Urey published his results in a paper titled "The thermodynamic properties of isotopic substances" (J. Chem. Soc. 1947 Apr: 562-81).

The technique works because ¹⁶O evaporates preferentially from oceanic and lake water, compared to ¹⁸O. Some of those isotopes then return to the water (e.g. through rainfall and runoff) but some also fall to the land as snow. In cold periods with snow and glacial ice buildup, this process extracts more ¹⁶O than ¹⁸O from the water, so the ratio changes. The ratio is therefore a proxy for the volume of glacial ice on the planet as well as for temperature.

The technique became a cornerstone of the science of paleoclimatology. It has been used by many other climatologists, including Shackleton. Calculations using it have been compared to those from the Milanković's theory. Both agree broadly on a long series of relatively warm and cold periods extending back at least 2.6 million years. Those periods are called Marine Isotope Stages (MIS) or Oxygen Isotope Stages (OIS).

Urey can be considered the "father" of this field of study, referred to generally as isotopic paleoclimatology.

Kapitsa, Pyotr L. (1894 - 1984)

Pyotr Kapitsa was a Soviet physicist. While out of favour with Stalin in the late 1940s and early 1950s due to his refusal to work on nuclear weapons development, he conducted research on ball lightning. He won the Nobel Prize for physics in 1978.

Schonland, Sir Basil (1896 - 1972)

Basil Schonland was a South African physicist who studied atmospheric electricity and lightning. In 1937 he was selected as the founding director of the Bernard Price Institute of Geophysical Research at the University of Witwatersrand, where from 1937 to 1939 he chased storms, photographed lightning and measured the electrical fields around and under thunderclouds. His work in the area of lightning was hailed as the greatest advance in the field since the studies of Benjamin Franklin.

Schonland also played a key role in South Africa's independent development of radar during World War II. He was voted South Africa's Scientist of the Century in 1999.

Dumbrava, Constantin (1898 - 1935)

Constantin Dumbrava was a Romanian naturalist and polar explorer. He was involved in three expeditions to Greenland. The first, in 1927-1928, took place in the Angmassalik region, where he made an ethnographic study of the native people, and completed work in glaciology and meteorology. The second expedition took place in 1930-1931, in the Scoresby Sund area. Dumbrava was left on the east side of Hurry Inlet in the summer of 1930, where he built a hut for shelter. During his time there he made meteorological and magnetic observations and studied sea currents and tides, and the sea temperature. He returned home in 1931. The third expedition in 1934 was disastrous. The balloon carrying him to Greenland crashed in the water off the Angmassalik coast. Dumbrava was injured and contracted pneumonia and never recovered. He died a year later in France.

Post, Wiley (1898 - 1935)

Wiley Post was an American aviation pioneer. In 1931 he and navigator Harold Gatty flew around the world in eight days, 15 hours and 51 minutes (the first round-the-world flight in 1924 had taken 175 days!). In 1933 Post became the first man to fly solo around the world (and did it in just less than 8 days). During both circumnavigations, he took advantage of strong westerly tailwinds that he found were sometimes present at the higher altitudes at which he flew. This was his first hint of strong upper-level winds that would come to be known as the jet stream.

In 1934, Post turned his attention to the potential of long-distance, high-altitude flight. He developed, with the BF Goodrich Company, a pressure suit that allowed him to take his airplane, the Winnie Mae, into the stratosphere. In test flights later that year, he flew as high as 50,000 feet and confirmed the existence of the jet stream. (Johannes Georgi had discovered the jet stream during his work in northern Greenland in 1926 and 1927, and made what appears to be the first written reference to it in 1933 in his book Im Eis Vergraben (translated in 1934 into English as Mid-Ice: the Story of the Wegener Expedition to Greenland)).

In 1935, Post attempted four non-stop transcontinental stratospheric flights from California to New York (22 February, 15 March, 14 April and 15 June). All, however, ended in mechanical failure, but in some he did succeed in taking advantage of the jet stream. For example, in the March flight he got as far as Cleveland OH, using the jet stream to increase his ground speed to an average of 279 mph. At times his ground speed hit 340 mph. (The Winnie Mae, a Lockheed Vega, had a normal cruising speed of 179 mph).

In August 1935, Post and his friend Will Rogers died near Point Barrow, Alaska when the airplane Post was piloting crashed on takeoff.

Another meteorological legacy left by Post is that he inspired the American author and artist Eric Sloane. In 1933, Post taught Sloane to fly in exchange for art lessons, and during his first flights with Post, Sloane fell in love with the aerial view of the sky and clouds that lay beneath him. "Some day", Post told him, "a fellow will come along and paint nothing but the sky itself. Where else can you find higher mountains? Look at the cumulonimbus over yonder - twice the height of the Matterhorn and twice as beautiful. Where else but up here could you see a better landscape of clouds?" Sloane replied "What you mean is a cloudscape, and I wouldn't be surprised if the first fellow to try painting cloudscapes turns out to be me." Sloane indeed became a prolific painter of cloudscapes, and the author of meteorological works as well. His first book, Clouds, Air and Wind was published in 1941 and was adapted by the US Army Air Corps as a basic weather manual for pilots. Many other weather-related books would follow.

Sorge, Ernst (1899 - 1946)

Ernst Sorge was a German geographer, glaciologist and polar researcher who participated in the German Greenland expedition of 1930 with meteorologists Alfred Wegener, Johannes Giorgi and Fritz Lowe. The expedition studied the meteorology and glaciology of the Greenland ice cap. Unfortunately Wegener died during this expedition.

Georgi would later describe Sorge's work: "Sorge measured the density of blocks of nevé cut at different levels of his shaft. He succeeded, with this primitive equipment, in distinguishing the strata of the precipitation of summer and winter, and of measuring its content of water, for 20 years back to 1911!" This pioneering research on the glaciology and climatology of Greenland was conducted during the winter of 1930-31 at the Eismitte station on the Greenland ice cap.

Nakaya, Ukichiro (1900 - 1962)

Ukichiro Nakaya was a Japanese physicist who studied the crystal structure of snow and ice. Starting in the 1930, he was a professor of physics at the University of Hokkaido.

Nakaya was captivated by the beauty of snowflakes. His research included taking photographs of snowflakes and ice crystals, producing artificial snow crystals, and studying the relationship between crystal structure and meteorological conditions. He created the first snowflake classification system, was the first person to systematically study the formation of snow crystals, and the first to grow artificial snowflakes under controlled laboratory conditions. Nakaya also contributed to pioneering scientific documentaries in the late 1930s and early 1940s, including Snow Crystals and Frost Flowers.

In 1994, the Ukichiro Nakaya Museum of Snow and Ice was established in his home town of Katayamazu,

Bower, S. Morris (ca 1900? - 1982)

Morris Bower was a British amateur meteorologist who in 1924 set up in his home an organization that he called the Thunderstorm Census Organization (TCO). It existed until his death in 1982. Its goal was to record thunderstorm activity in the UK. To this end, volunteer observers were recruited, and printed-to-private-order postcards were distributed to them. They were to be used for all thunderstorm observations to ensure standard reporting procedures. The design of these postcards remained changed little through the life of the TCO. They included on the back a blank compass rose on which the observer could plot the motion of the thunderstorm. From its humble beginnings, the TCO grew to have over 3,000 volunteer observers in 1937. Indeed, the 1930s were its heyday. There were also TCO subgroups charged with, for example, investigating trees struck by lightning, building structural damage, damage to means of land transport, and personal injuries due to thunderstorms.

Bower published some results of the TCO's work in scientific journals, including:

• Bower, S. Morris, 1950. Recent Work of the Thunderstorm Census Organisation, Q. J. Roy. Meteorol. Soc., vol.76, no.330, p.455-465.
• Bower, S. Morris, 1947. British Thunderstorms, 6th Report, 1936-37. Q. J. Roy. Meteorol. Soc., vol.74, no.321-322, p. 422.
• Bower, S. Morris, 1932. A Census of Summer Thunderstorms. Nature, 130, 15 October 1932, p.587-588)
• Bower, S. Morris, 1927. Winter Thunderstorms, Nature, 120, 10 December 1927, p. 842.

The TCO became part of the British TORRO (Tornado and Storm Research Organisation) in 1982.

Simmons, R. J. (ca 1900? - ?)

R. J. Simmons was the expedition meteorologist on the 1930-31 BANZARE (British, Australian and New Zealand Antarctic Research Expedition).

Lindbergh, Charles (1902 - 1974)

Charles Lindbergh was the American aviator who made the first solo nonstop crossing of the Atlantic, (from New York to Paris) in May 1927.

Lindbergh was convinced that commercial aviation was destined to have a rosy future. As a pilot, however, he knew that weather could have a major effect on aircraft operations. In an interview in Popular Mechanics (November 1927), he identified two conditions of particular difficulty and potential danger to pilots (his use of the term "sleet" refers to freezing rain):

"Airplanes can fly now under all conditions but in sleet … sleet forms on the wings and changes the camber, in addition to increasing the weight. Heating the wings or some other method will change that. The only other difficulty is flying in fog. The actual flying is not hard, for with modern instruments a pilot can take off today and fly without seeing ground or sky for a long time. In landing, however, he has trouble. This latter obstacle will be overcome in the near future by radio signals, fog-piercing lights, special altitude instruments or some other means. The radio beacon is a great help in fog, as a pilot can tell when he is even slightly off his course on either side."

As a result of the effects of weather on aircraft operations, Lindbergh foresaw that weather forecasting would become increasingly important as an integral part of commercial aviation. He stated that "experts will provide complete weather forecasts and reports for any desired route or airport on a route, to eliminate danger of flying into bad conditions. Most of this information will be given planes in the air by radio. Airplane pilots will receive orders just as engineers now get them from train dispatchers, and lines will be handled as methodically as railroads."

Lindbergh made several aviation surveys for Juan Trippe, the owner of Pan American Airlines. In one of them, Lindbergh and his wife Anne traveled in 1933 as far as Moscow, searching for potential new terminal sites for Pan American in northern Europe. During that trip he compiled a report on meteorology and other issues of importance to commercial aviation, in which he concluded that there was favourable potential for service to Europe. He presented the report to Trippe in 1934.

In his later years, Lindbergh was outspoken on environmental issues such as the plight of the humpback and blue whales. He also objected to the development of supersonic jets because of their potential effects on the stratosphere.

Kaplan, Joseph (1902 - 1991)

Born in Hungary, Joseph Kaplan moved to the US at age 8. He became an American citizen and earned a doctorate in physics in 1927. He becam an assistant professor at UCLA in 1928, and immediately began work on reproducing the spectrum of the aurora in his laboratory. In 1932 he succeeded in producing an afterglow, which he felt did reproduce auroral conditions. He concluded that "the auroral display is really an electrical discharge in a nitrogen-oxygen mixture in which metastable molecules abound". In fact some of the emissions he discovered in his lab were only later observed to be part of the upper atmospheric night sky spectrum.

During WWII, Kaplan and Karl Gustav Rossby of the University of Chicago organized for the US Air Force a major program to train military personnel in meteorology at several universities across the country. Verner Suomi was one famous alumnus of this program.

Kaplan became a full professor of physics at UCLA in 1940. From1943 to 1945 he was the chief operations analyst for the Air Force and the Air Weather Service. In 1944 he established the Institute of Geophysics at UCLA, of which he was the director in 1946 and 1947. He continued to be interested in the upper atmosphere, and particularly in how the ionosphere and solar activity would affect radio transmissions. To this end, he considered the exploration of the upper atmosphere with instrumented rockets (Robert Goddard had made the first attempt to launch such a rocket in 1929). Kaplan studied the chemical reactions in the upper atmosphere, and especially those that led to the production of the afterglow. He suggested that the region of the atmosphere where those chemical reactions take place be called the chemosphere (as an analogue to the name "ionosphere", where reactions among ions occur).

Starting in 1953, Kaplan served as chairman of the US Committee for the IGY (International Geophysical Year), where he advocated the launching of artificial satellites to explore the Earth's upper atmosphere as part of the scientific program (and in fact the first artificial satellites (Sputnik-1, Vanguard-1 and Explorer-1) were indeed launched by the USA and the USSR as part of the IGY). Kaplan described his plans for the IGY at a lecture at the University of Wisconsin in Madison in 1956. Verner Suomi was present, and enthusiastically shared with Kaplan his ideas about satellite measurements of the Earth's heat balance. This led to the development of the Suomi-Parent radiometer that was aboard the satellite Explorer-7. It was launched in 1959, after the IGY had ended. Nevertheless, it was an important step forward, and provided the first measurements of the Earth's heat budget and its changes in space and time.

Kaplan was active in the International Union of Geodesy and Geophysics in the 1950s, and with Sidney Chapman and Lloyd Berkner introduced the term "aeronomy" to describe the scientific study of the upper atmosphere. In the 1960s he was a member of the Executive Committee of the International Committee of Scientific Unions. During those years he played an important role in international programs such as the IQSY (International Quiet Sun Year), IHD (International Hydrological Decade) and the GARP (Global Atmospheric Research Program). In 1969, Kaplan received the Commemorative Medal for the 50th Anniversary of the American Meteorological Society.

von Neumann, John (1903 - 1957)

John von Neumann was born in Hungary, but immigrated with his family to the United States in 1930. He was a mathematician, computer scientist and meteorologist who pioneered the use of computers in applied scientific problems, including meteorology.

In 1946 he announced his "intention of developing a very high speed electronic computing machine". In collaboration with the US Weather Bureau, the Navy and the Air Force, he formed the Meteorology Group at Princeton's Institute for Advanced Study (IAS). His computer work proceeded apace at the IAS during the late 1940s, culminating in the revolutionary computing machine ENIAC. The world's first computerized weather forecast was produced in 1950 by ENIAC. This pioneering work in numerical weather prediction (NWP) was described in a scientific paper written by von Neumann and his colleagues Jule Charney and Ragnar Fjörtoft in 1950. Entitled Numerical Integration of the Barotropic Vorticity Equation (published in the meteorological journal Tellus, vol.2, p.237-254), it is the earliest scientific paper in the area of NWP.

Von Neumann also pursued his other meteorological interest: "calculating the effects of human intervention in the natural processes of the atmosphere". He proposed to apply computer techniques to study the idea of adding dye to the polar icecaps to decrease the amount of solar energy they would reflect. He claimed that the procedure could warm the Earth enough to make the climate of Iceland approximate that of Hawaii. He also predicted the warming of the climate due to carbon dioxide release.

In 1953, the US Advisory Committee on Weather Control was created to oversee American weather modification and cloud seeding activities, such as those originated by Irving Langmuir and Vincent Schaefer after WWII. Von Neumann became involved with the Committee in 1955 (at the time he was also a commissioner of the Atomic Energy Commission, and so was involved with the development and stockpiling of nuclear weapons). He believed that in weather control as well as in the nuclear arms race, the US had to stay ahead of the Soviets at all costs. Like the US military, he considered weather control as a potential tool for achieving global dominance, and as part of the Advisory Committee he participated in a panel on the "possible effects of atomic and thermonuclear explosions in modifying weather". Another area of discussion was how Soviet harvests might be ruined by a US-induced drought. Yet another was that atomic bombs detonated off the west coast of Africa at the onset of the monsoon might improve the climate of the drought-prone Sahel region. As von Neumann naively told Congress in 1956, "our knowledge of the dynamics in the atmosphere is rapidly approaching a level that will make possible, in a few decades, intervention in the atmospheric and climatic matters. It will probably unfold on a scale difficult to imagine at present. There is little doubt one could intervene on any desired scale, and ultimately achieve rather fantastic effects". But already in 1957, Roger Revelle and Hans Seuss were raising warning flags with their ominous findings on increasing CO₂ levels in the Earth's atmosphere which hinted at anthropogenic global warming. It seems that von Neumann never considered, at least in public, that major weather modification projects carried out in the atmosphere might spiral out of control and lead to unexpected effects.

Krenkel, Ernst (1903 - 1971)

Ernst Krenkel was a Russian polar researcher and geographer. He began his career as radio specialist (he was also an amateur radio operator) on Soviet polar expeditions, including the North Pole-1 (NP-1) drifting ice station, where he served with the meteorologist Fedorov and transmitted the first ever weather report from near the North Pole. He also took part in the Sibiryakov and Chelyuskin expeditions (both of which were commanded by Otto Schmidt). Starting in 1938, Krenkel worked for the Chief Directorate of the Northern Sea Route, which had responsibility for marine navigation, weather observing and radio communications throughout the Northeast passage. In 1951 he joined the research division of the Hydrometeorological Instruments Institute, of which he became the director in 1969. Krenkel was co-leader, with D. Maksutov, of the 14th Soviet Antarctic Expedition, from 1967 to 1969. During that expedition a wide variety of scientific programs was carried out, including programs in meteorology, aerology and the aurora.

The Hydrometeorological Observatory on Heiss Island in Franz Josef Land was named for Krenkel in 1972. At the Observatory, the USSR and France cooperated in meteorology, aeronomy and space studies. It was closed in 2001 after a fire, but reopened in 2004 as the E. Krenkel Polar Station. It is still part of the hydrometeorological observing network, with synoptic station number 20046. Krenkel's name was also given to a research vessel of the Hydrometeorological Service Gidrometsluzhba.

¹NP-1 (North Pole 1) was the first Soviet Arctic drifting ice station. It had a crew of four (leader Papanin, and Krenkel, Fedorov and Shirshov) and operated from May 1937 through February 1938.

Kolmogorov, Andrei Nikolaevich (1903 - 1987)

Andrei Kolmogorov was a Russian mathematician. He was a student and then post-doctoral researcher at the Lomonosov Moscow State University from 1920 to 1931, and was a professor there from 1931 until his death.

During the WWII years, he worked on various applied and theoretical scientific problems in addition to his pure mathematical research. One such problem was turbulence. He made important contributions to the understanding of the small-scale structure of turbulence and the energy transfer process from large to small scales (through a process known as the "energy cascade", first proposed by the meteorologist L. F. Richardson) through his development of what came to be known as the similarity theory of turbulence. This was the first mathematical analysis of turbulence. The theory has found application in many areas of science, including atmospheric studies. For example, the dispersion of atmospheric pollutants depends on turbulence. Also, it is well known that turbulence in the clear atmosphere can affect even the largest aircraft.

Kolmogorov's student A. M. Obukhov became head of the Turbulence Laboratory in 1949, and later was the founder and director of the Institute of Atmospheric Physics of the Russian Academy of Sciences.

Kibel, I. A. (1904 - 1970)

I. A. Kibel was a Soviet mathematician, meteorologist and fluid hydrodynamicist. After graduating from the University of Saratov in 1925, he worked at the Main Geophysical Observatory in St. Petersburg until 1943. From 1943 to 1958 he was at the USSR Central Forecasting Institute, from 1958 to 1961 at the Institute of Applied Geophysics, and after 1961 at the USSR Meteorological Computing Centre (which became the USSR Hydrometeorological Centre in 1965). Through much of his career, Kibel was mainly interested the application of numerical techniques to short term weather forecasting. He also considered the mesoscale and its effects on weather forecasts.

In 1940 Kibel developed a simple equation for surface pressure tendency and proposed a graphical method for solving it to obtain 24 hour forecasts of surface pressure. The scheme was tested in the 1940s but the results were less than satisfactory. This was, however, the earliest Soviet attempt to make weather forecasts based on meteorological dynamical equations of motion, and Soviet NWP (numerical weather prediction) can be traced back to this point. Obukhov in 1949 published a paper that treated the mutual adjustment of wind and pressure in a barotropic atmosphere. Kibel extended Obukhov's work to a more complete set of dynamical equations in the 1950s. The work of Kibel, Obukhov and other researchers led to the first operational NWP system in the USSR in 1959. Kibel also founded a School of hydrodynamical short-range weather forecasting at the Forecasting Institute.

Kibel's meteorological publications (in Russian) include:

• Kibel, I. A., 1940: Application to meteorology of the hydrodynamic equations of a baroclinic fluid. Izv. Akad. Nauk SSSR, Ser. Geograf. i Geofiz. No.5, 627-638.
• Kibel, I. A., 1951: A new method of short-range prognosis of meteorological elements. Trudy. Ts. Inst. Prog., No 31.
• Kibel, I. A., 1955: On the adaptation of air motion to geostrophicity. Doklady Akad. Nauk SSSR, 104, 60-63.
• Kibel, I. A., 1957a: The analysis of geostrophic motion in the prediction of weather. Trudy. Ts. Inst. Prog., No 60, 3-9.
• Kibel, I., A., 1957b: Introduction to the hydrodynamic method of short-range weather prognosis. Gosud. Izdat. Tek.-Teor. Lit., Moscow, 375 pp.
• Kibel, I. A., 1958: A method of short range prognosis of meteorological elements. Doklady Akad. Nauk SSSR, 118, 687-690.
• Kibel, I. A., and E. Blinova, 1957: Hydrodynamical methods of short and long range weather forecasting in the USSR. Tellus, 9, 447-463.
• Kibel, I. A., 1970: Hydrodynamic Short-Term Forecasts in Mesometeorological Problems: Publications GMTs, no.48, 3-33, 1970.
• Kibel, I. A., 1984: "Mode of short-term forecasting of meteorological elements" and "A finite difference scheme for solving the complete system of equations of short-term forecasting and quasigeostrophic relations" (both in Selected Works of I. A. Kibel on Dynamic Meteorology, Leningrad, 1984).

Rymill, John (1905 - 1968)

John Rymill was an Australian polar explorer. In 1930-1931 he participated in his first Greenland expedition, designed to explore an almost unknown part of Greenland and record meteorological conditions at the coast and over the ice cap for a period of about one year. In 1932-33 he was part of another Greenland expedition. Its goal was to complete the meteorological and survey work of the first expedition.

Rymill also went to Graham Land in Antarctica as part of the last British expedition to that continent before WWII. There he participated from 1934 to 1937 in a comprehensive scientific program that studied geology, meteorology, glaciology and biology. In addition, the survey work carried out by the expedition showed that the Antarctic Peninsula is part of the Antarctic mainland.

Sartre, Jean-Paul (1905 - 1980)

Jean-Paul Sartre was a French writer and philosopher. After graduating from the École Normale Supérieure, he did his compulsory military service as an Army meteorologist at Fort St-Cyr and at St-Symphorien, near Tours, from 1929 to 1931. In 1939 he was drafted into the French army and served as a meteorologist in the war until his capture by German troops in 1940.

Andranik Gevondovich, Iosifyan (1905-1993)

Iosifyan Andranik Gevondovich was an Armenian electrical engineer who worked on high tech electromechanical projects in the USSR. He was the founder and first director of the Soviet Research Institute for Electromechanics. In the 1960s and 1970s he was the chief designer of the Meteor series of meteorological satellites and the Meteor-Priroda series of environmental-observing satellites. He also directed the design and production of the Omega and Interkosmos-Bulgariya 1300 scientific satellites.

Tu, Chang Wang (1906 - 1962)

Chang Wang Tu was a Chinese meteorologist. After graduating from Hujiang University in 1929, he went to the University of London to study economics and geography, but transferred to the meteorology program at the Imperial College of London in 1931, where he obtained his M.Sc. in meteorology. He became a member of the Royal Meteorological Society of the UK. In 1934 he accepted an invitation from Zhu Kezhen to return to China as a researcher at the Institute of Meteorology at the Central Academy. He was later a professor of meteorology at Tsinghua University, Zhejiang University and Central University.

In 1949 Tu became the first director of the Weather Bureau of the Central Military Commission (which eventually became the Central Meteorological Bureau, which was in turn the precursor of the Chinese Meteorological Administration). Tu occupied this position until 1962, and under his leadership Chinese meteorology made vast strides forward. Indeed, Tu was on of the pillars of modern Chinese meteorology.

In 1955, Tu expressed something of his philosophy in the first issue of the Chinese journal Weather Monthly. He said that in the weather offices there should be diligent study and friendly competition to improve the quality of work. He advocated that forecasters must use all their talents, emphasize research, build from their strengths and constantly improve their operational skills.

References:

• Tu, Chang-Wang. On China Rainfall and World Weather (Discussion of Memoir). Q. J. Roy. Meteorol. Soc., vol.60, no.254, April 1934, p.167-168.

This short article outlines Tu's M.Sc.studies, in which his goals were (1) to discover the relationship between the rainfall of China for the rainy season and world weather; and (2) to find regression formulas that could be used to predict Chinese rainfall of the rainy season. In particular, he was searching for a way to predict big departures from the normal. Such departures in China can be related to either disastrous floods or droughts, depending on the direction of the departure. To do this, Tu calculated correlation coeffiecients of Chinese rainfall with the pressure, temperature and rainfall at various major observing stations around the world.

• Tu, Chang-Wang. Chinese Air Mass Properties. Q. J. Roy. Meteorol. Soc., vol.65, no.278, January 1939, p.33-51.

This is a study of typical Chinese airmasses and their properties, origins and processes of modification, based on various airplane, kite and pilot balloon soundings sounding from several Chinese locations. Tu defines a total of six airmass types: those of Polar, Tropical or Equatorial origins, each with maritime or continental characteristics.

Victor, Paul-Émile (1907 - 1995)

Paul-Émile Victor was a French polar explorer, scientist and administrator. In 1947 he created the organization Expéditions polaires françaises, Missions Paul-Émile Victor (EPF Missions PEV). In 1948 he began a long series of expeditions to Greenland to investigate the ice cap. His work there included meteorological, geophysical and glaciological observations. Those trips culminated in the International Greenland Glaciological Expedition that took place from 1957 to 1960.

In the 1960s Victor led expeditions to the south Polar region. For example, as leader of the Magga Dan voyage, he was, with meteorologist Alfred Faure, part of the team of 12 men that established a camp on Île de la Possession in the Îles Crozet on 20 December 1961. The group remained there until 3 February 1962. They made meteorological observations, conducted other scientific studies and selected the site for an eventual permanent station. That station, constructed in 1963, opened formally in 1964 and was later named the Alfred Faure station. In the austral summer of 1966-1967, Victor, as leader of the Thala Dan voyage, was part of a team (again with Faure) that launched four Dragon research rockets in late January 1967 (here are a stamp and a cover referring to those launches) from the Dumont d'Urville base in Adélie Land. Designed for ionospheric research, these successful flights reached about 300 km altitude.

Victor directed the Expéditions polaires françaises until 1976. The goal of the EPF was the study of the polar regions through new disciplines such as glaciology, polar meteorology and extreme conditions medicine. The EPF built a strong scientific record in those areas and its successor, the Institut polaire français Paul-Émile Victor (IPEV), continues that tradition of excellence in polar research, including climatological and atmospheric studies.