A Comparison of Tropical Mesoscale Convective Systems in El Niño and La Niña

Abstract

Abstract 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 regions. There are well-documented patterns of anomalous precipitation related to El Nino and La Nina, and, in general, the MCS distributions between the two years tend to follow these patterns. There were more MCSs in the central Pacific and eastern Pacific in the El Nino year than in the La Nina year, and there were fewer MCSs in the “Maritime Continent.” The area distributions and median intensities of MCSs were found to be similar in each region 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 distributions showed a strong relatio...