A Methodological Approach to Assess the Co-Behavior of Climate Processes over Southern Africa

AbstractThe study develops an approach to assess co-behaviour of climate processes. The regional response of precipitation and temperature patterns over southern Africa to the combined roles (co-behaviour) of El Nino Southern Oscillation (ENSO), Antarctic Oscillation (AAO) and Inter-Tropical Convergence Zone (ITCZ) is evaluated. Self-Organizing Maps (SOMs) classify circulation patterns over the subcontinent and Principal Component Analysis (PCA) used to identify related patterns across the data. The Tropical Rain Belt Index (TRBI), a measure of the ITCZ, is generally in phase with the AAO but mostly out of phase with ENSO. The phases of AAO may enhance or suppress ENSO impact on the location and distribution of regional precipitation and temperature over the region. This understanding of the co-behaviour of large scale processes is important to assess the impact these processes collectively have on precipitation and temperature, especially under future climate forcings.