Articles | Volume 8, issue 1
Hydrol. Earth Syst. Sci., 8, 115–118, 2004
https://doi.org/10.5194/hess-8-115-2004
Hydrol. Earth Syst. Sci., 8, 115–118, 2004
https://doi.org/10.5194/hess-8-115-2004

  29 Feb 2004

29 Feb 2004

The origin of summer monsoon rainfall at New Delhi by deuterium excess

Hongxi Pang1, Yuanqing He2,1, Zhonglin Zhang1, Aigang Lu1, and Juan Gu1 Hongxi Pang et al.
  • 1Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, China
  • 2Institute of Tibetan Plateau, Chinese Academy of Science, Beijing 100029, China
  • Email for corresponding author: phx_anu@hotmail.com

Abstract. The deuterium excess in summer monsoon precipitation, determined from isotopic measurements(δ18O and <δD) at New Delhi, has been shown to be correlated, negatively, with relative humidity at the 1000 hPa level over the western Arabian Sea. Furthermore, summer rainfall in north-western India is correlated, positively, with the zonal wind speed at the 1000 hPa level over the western Arabian Sea, while relative humidity is correlated, negatively, with zonal wind speed at the same level. It is concluded that evaporation from the western Arabian Sea is a major source of the summer rainfall at New Delhi.

Keywords: deuterium excess, relative humidity, origin of precipitation