Regional And Mesoscale Meteorology Team
Daily Satellite Discussion
Thursday November 6, 1997
In this image one can see the well-defined change in grey scale from southwest to northeast Wyoming. Also from northeast Colorado northward to South Dakota and from southern Iowa northward to Minnesota.
The variation of grey scale can be due to many different factors, two of which are;
1) The optically thick layer may be at the same physical height above the ground. The cooler brightness temperatures that one sees can be due to the air temperature simply being cooler over northeast Wyoming compared to southwest sections of that state.
2) The optically thick layer may exist at higher levels over northeast Wyoming as opposed to southwest Wyoming. If the environment is cooler at higher levels then the brightness temperatures over northeast Wyoming will be lower than those over southwest Wyoming.
The change in grey scale can be valuable information for determining vertical motion on isentropic surfaces. If air parcels can be shown to be moving northeastward from southwest Wyoming then this would be an example of isentropic lifting. Diagnosing vertical motion is very important during the warm season for forecasting deep tropospheric convection ahead of advancing baroclinic waves.