ABSTRACT - DRUM - University of Maryland

not quantitatively indicate the extent to which they are mixing with their environment.
Global analyses of cloud height do exist [e.g., Gettelman et al., 2002]. These analyses
usually use brightness temperature from satellites to infer cloud height. However, the
conversion from brightness temperature to altitude is uncertain [Sherwood et al., 2004]
and therefore conclusions reached from these analyses require independent verification.
In this study, an alternative method is used to determine the height of convecting
clouds, as well as how much they mix with air in the TTL.
3.2 Data
To study overshooting convection, the data from the Visible and Infrared
Scanner (VIRS) [Kummerow et al., 1998] onboard the Tropical Rainfall Measuring
Mission (TRMM) [Simpson et al., 1996] are utilized. Four time periods (January 1998,
July 1998, January 1999, and July 1999) are used in the analysis. These years are
characterized by winter and summer seasons from both an El Nino (1998) and La Nina
year (1999). VIRS makes measurements at five wavelengths (0.63-, 1.6-, 3.75-, 10.8-,
and 12.0- µm) with a horizontal resolution of 2 km at nadir. In this study, data from the
0.63-, 3.75-, and 10.8-µm channels are used. In addition, the 2.5º × 2.5º surface
temperature and relative humidity from National Center for Environmental Prediction
(NCEP) reanalysis [Kalnay et al., 1996] are used as initial conditions of an adiabatic
altitude model.
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