A climatological analysis of isentropic fields

Isentropic analysis has recently regained some of the popularity it had in the 1930s and 1940s. Much of the early research done in that period was of the monthly averaged time frame. This research resumes this type of study, although it concentrates solely on Aprils as opposed to the early studies which concentrated more on the summer months. This research uses an objective analysis scheme to analyze certain meteorological fields on 300K isentropic surfaces. The multitude of variables studied allows a more complete look at the happenings on an isentropic surface than was possible in the 30s and 40s. The study covered eleven parameters over thirteen years from 1967-80. Maps were generated for each of the parameters for each April, plus averages for each parameter for the thirteen Aprils, and deviations from the average. In all, over 300 graphics were produced. Overall, the testing showed success by using both moisture and dynamic variables to show how temperature and precipitation anomalies could be explained. Some problems with moisture-dependent variables being tainted by anomalously high or low isentropic surfaces were adjusted in a comparison to pressure values. This comparison allowed a more accurate depiction of the specific variable's contribution by showing what was normal for high or low isentropic surfaces. This adjustment made for higher correlations with the precipitation verification maps. The explanation of temperature anomalies needed no such adjustments and had few difficulties in the verification process.