Pre-monsoon zonal wind Index over Tibetan Plateau and sub-seasonal Indian summer monsoon rainfall variability



[1] In this paper, by using the Principal Component Analysis (PCA) technique monthly zonal wind indices over Tibetan Plateau (25°N–45°N, 75–105°E) (TP) at 200 hPa have been constructed for the period 1948–2006. These indices are referred as Tibetan Zonal Wind Index (TZWI). The relationship between the TZWI and Indian summer monsoon rainfall on monthly basis has been studied by the correlation analysis. From the analysis, it is observed that pre-monsoon months (April and May) of TZWI show the significant inverse relationship with June and July rainfall over India respectively. The study may be useful for forecasting rainfall activity in June and July months, which are crucial months from the agricultural point of view.