Differences between Kinetic Energy Budget Terms Derived from SESAME and NWS Data Sets

Abstract

Upper air data collected during AVE-SESAME 1, 1200 GMT 10 April 1200 GMT 11 April 1979, are used to detect differences between calculations of kinetic energy budget terms derived from two sets of analyses. Barnes's objective analysis scheme is used to grid both sets of analyses, one based on all data taken in the regional AVE-SESAME network (SES) and the other based on data taken only at the National Weather Service stations (NWS) within that network. The SES analyses were derived from data taken at 23 NWS stations plus 16 supplementary stations. Four areas are examined: 1) the total analysis area, 2) a smaller fixed area that contains most of the active convection throughout the period, 3) a still smaller, but varying area that contains the strongest convective activity as determined from Manually-Digitized Radar (MDR) data and enhanced IR satellite imagery and 4) another varying small area downstream from the strong convective activity that contains no detectable convection. The most significant difference between SES- and NWS-derived budget terms occurs in the kinetic energy generation term. In all areas except the no convection area, generation values are considerably more positive when the SES data set is used. Most of the difference occurs in the upper troposphere. Furthermore, both data sets show that generation occurs in convective areas, whereas destruction predominates elsewhere.