Connell, Vaughn
 
     The Costa Rica RAMSDIS ingest system was upgraded to McIDAS 7.0.

    Hourly climatology imagery (Visible, 3.9 µm, 6.7 µm and 10.7 µm) for January and February 1998 were sent to Costa Rica.   We are into the second year of data collection and this has afforded the opportunity to start comparing imagery from both years.   So far, imagery from December 1997, January 1998, and February 1998 are indicating drier conditions than in December 1996, January 1997, and February 1997.  Examples of monthly comparisons can be seen on the Web:

                  December - http://www.cira.colostate.edu/ramm/picoday/12898.html
                  January - http://www.cira.colostate.edu/ramm/picoday/980211.html
                  February - http://www.cira.colostate.edu/ramm/picoday/980326.html

    Plans are in progress with Rosario Alferro to quantify the frequency of fires in Central American Countries during the dry months of January, February, March, and April.  The archived climatology imagery will allow us to look at 1997 as well as 1998.

    A CD containing daily imagery from February 1998 was sent to the Regional Meteorological Training Centre (RMTC) in Barbados.  The March 1998 imagery is being compiled and will be sent to Barbados by the first week of April 1998.  Minimum, maximum, and average brightness counts were computed from the hourly data for the month of February  in hopes of revealing preferred locations for convection or clouds at different times of the day.  Since February was a rather dry inactive month, we expect this ongoing project to be very worthwhile during the convective season.

    The following are examples of average images and products derived from the Goes-8 monthly imagery.  (Click on images for full size display.) 

Figure 1.  Average image of the visible channel, compiled from imagery at 1815 UTC for the month of February,  showing the island wake clouds, which appear daily and are caused by convergence in the boundary layer.  The  "octopus" appearance of the clouds in this  image is due to shifting in the orientation of the Easterly Trade Winds on a day to day basis. 

Figure 2.  Image derived by taking the maximum brightness count (minimum temperature) for each pixel that occurred at 1815 UTC during the month of February, in the longwave IR channel 4.  It reveals the lack of convective activity during the month of February for the Windward and Leeward Islands. 

Figure 3.  Water Vapor average image, where the reddish and dark grey areas indicate warm temperatures in the upper levels,  showing evidence of sinking aloft and is likely to be the reason for the lack of deep convective activity found in the IR max image shown above.