Influence of southwest monsoons in the Kashmir Valley, western Himalayas.

The regional climate of the Himalayas is predominated by the southwest monsoons and the western disturbances. The uplift of the Pir Panjal to its present height is believed to restrict the southwest monsoons from entering into the Kashmir Valley in the western Himalayas. In the present study, monthly precipitation samples were collected across the Kashmir Valley from June 2013 to May 2014 for δ18O and δ2H analyses to constrain the influence of southwest monsoons in the valley. Except in August, the precipitation is enriched in 18O and 2H from June to September and depleted from October to May. The sharp depletion of 18O in precipitation along with the decrease in d-excess in August confirm the maximum intrusion of southwest monsoons into the valley. A significant temperature - δ18O relationship was found during October and May (westerlies period) decreasing during June and September (southwest monsoon period). The local meteoric water line for the whole Kashmir Valley based on the precipitation-weighted monthly samples is [Formula: see text] [Formula: see text]. Higher intercept of the regression equation suggested dominant contribution of precipitation from western disturbances. The study suggested that the southwest monsoons enter the Kashmir Valley from southwest through the mountainous passes.