RAMM/CIRA 2nd Quarter Report
Extra Tropical Cyclones (Bikos, Dostalek, Weaver)
J. Dostalek submitted an extended abstract for the proceedings of the First THORPEX International Science Symposium held in December 2004. The extended abstract is entitled “Analysis of Mid-latitude Cyclones and Fronts Using ATOVS Soundings” and is based on a poster given at the Symposium. Atmospheric profiles from the ATOVS (Advanced-TOVS [Tiros Operational Vertical Sounder]) data (which includes both infrared and microwave information) were used to analyze a mid-latitude cyclone that occurred over the eastern North Pacific on 19 December 2002. Temperature and moisture profiles from three NOAA-16 passes near 00:00 UTC were combined and gridded over the storm and its immediate environment. The hydrostatic equation was then integrated downwards from 100-hPa, giving the height of various pressure levels, as well as the surface pressure. The 100-hPa heights from the NOGAPS analysis were used as a boundary condition. Figure 1 shows the 700-mb potential temperature, q vectors, and q-vector divergence. The patterns of these fields match up well with the cloud structure as well as mid-latitude cyclone theory.
Click on figure to enlarge.
Figure 1. 700- hPa potential temperature (black, K), Q vectors (white), and Q vector divergence (white, x10 15 K m -2s -1, positive divergence dashed) at 00:00 UTC 19 December 2002, derived from ATOVS data .
In collaboration with CSU Professor Wayne Schubert, M. DeMaria and J. Dostalek submitted an International Polar Year pre-proposal to apply to polar lows the microwave intensity estimation technique which has been successfully implemented for tropical and mid-latitude cyclones. The technique is described briefly in this report under “Extra Tropical Cyclones.”
A general audience article, based on the article entitled, “Heavy Snowfall in the Midst of a Drought” by J. F. Weaver that appeared in the Fall 2004 issue of the CIRA Magazine is being revised for the Colorado Climate Magazine. The revision will include better graphics, and statistics which focus more on the climatology of the event.
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