A comparison of tropical mesoscale convective systems in El Nino and La Nina

Tropical mesoscale convective systems (MCSs) were identified from satellite data using the 85-GHz ice-scattering channel for a La Nina year, and these MCSs were compared with MCSs identified in the same manner for an El Nino year in previous work by Mohr and Zipser. The number size, and intensity of the MCSs were examined for differences between the years in 18 different r egions. There are well-documented patterns of anomalous precipitation relat ed to Ef Nino and La Nina, and, in general, the MCS distributions between t he two years tend to follow these patterns. There were more MCSs in the cen tral Pacific and eastern Pacific in the El Nino year than in the La Nina ye ar, and there were fewer MCSs in the "Maritime Continent." The area distrib utions and median intensities of MCSs were found to be similar in each regi on during the two years. In contrast, the number and total area of MCSs in a region changed between the years. The changes between the years in MCS di stributions showed a strong relationship to differences in an independent e stimate of rainfall for the two years.