Principal component analysis of sea-level pressure over the southwest Indian ocean during the northern summer of 1979

Abstract

Sea-level pressure over the southwest Indian Ocean has been studied for the northern summer season during the first Garp global experiment (FGGE) period. Grid point pressure values, resulting from objective analysis, at 1200 GMT for the period 15 June to 13 August 1979 were selected for this study. This period is referred to as the selected monsoon period and it lay between the Indian subcontinent monsoon onset and withdrawal periods. The space and time characteristics of sea level pressure in the region were estimated from principal component analysis and from spectral analysis respectively.