Convective Available Potential Energy and Convective Inhibition in ERA-Interim Reanalysis during the AMMA SOP Campaign

Abstract

A statistical analysis of Convective Inhibition (CIN) and Convective Available Potential Energy (CAPE) is conducted using a six-hourly ERA-Interim dataset for the summer of 2006 over West Africa as part of the African Monsoon Multidisciplinary Analyses (AMMA) SOP3 Campaign. This study analyses the trends and empirical orthogonal functions (EOF) of CAPE and CIN, along with the summer variability of CAPE and CIN with precipitation. CAPE exhibits its maximum over the continent around 14°N, while CIN peaks over the ocean. The variance of the main EOF is about 42% and its amplitude is low in the equatorial zone and slightly higher in the Sahelian regions. The variance of the second EOF is 16.4% and shows its maximum towards the south of Gambia. The significance of the trends of the pairs (first and second) of CAPE and CIN with rainfall is explored through the canonical correlation analysis (CCA) of these three parameters. The first and second pairs of CCA show a correlation of around 68% and 60%, respectively, with 12.2 and 10.8 degrees of freedom. The correlation coefficient at the 95% confidence level is 0.21 for the first CCA pairs and 0.65 for the second CCA pairs. In the Sahelian and Sudanese regions, the variance is approximately 78% and 73% respectively, primarily driven by the first CCA pair. The Guinea and wet equatorial areas are influenced by the second CCA pair, where the explained regional variance exceeds 60%.