Stable Isotope Systematics of Atmospheric Vapour at Hyderabad and Roorkee

Abstract

Stable isotopes (δ18O and δD) of ground level atmospheric vapour (GLV) are used to identify long range spatial correlation in moisture variability between two geo-graphically and geo-climatically different places Roorkee in the foot hills of Siwaliks in the north western part of the Gangetic plains and Hyderabad in the Deccan Plateau of peninsular India. A very good isotopic correlation in atmospheric moisture and absolute humidity was observed during 2008-10 in southern and northern part of India due to common (Arabian Sea and Bay of Bengal) dominant moisture source to both the regions but their magnitude in the total moisture and time of onset and duration is different in both the regions. These components and their timings are also changing in the recent years. In southern India, these are appearing early while are getting delayed in northern India. The results on long range correlation in GLV help understanding monsoon dynamics and climate change.