Reconstruction of the annual mass balance of Chhota Shigri glacier, Western Himalaya, India, since 1969

This study presents a reconstruction of the mass balance (MB) of Chhota Shigri glacier, Western Himalaya, India, and discusses the regional climatic drivers responsible for its evolution since 1969. The MB is reconstructed by a temperature-index and an accumulation model using daily airtemperature and precipitation records from the nearest meteorological station, at Bhuntar Observatory. The only adjusted parameter is the altitudinal precipitation gradient. The model is calibrated against 10 years of annual altitudinal MB measurements between 2002 and 2012 and decadal cumulative MBs between 1988 and 2010. Three periods were distinguished in the MB series. Periods I (1969-85) and III (2001-12) show significant mass loss at MB rates of -0.36 +/- 0.36 and -0.57 +/- 0.36 m w.e.a(-1) respectively, whereas period II (1986-2000) exhibits steady-state conditions with average MBs of -0.01 +/- 0.36 m w.e.a(-1). The comparison among these three periods suggests that winter precipitation and summer temperature are almost equally important drivers controlling the MB pattern of Chhota Shigri glacier at decadal scale. The sensitivity of the modelled glacier-wide MB to temperature is -0.52 m w.e.a(-1) degrees C-1 whereas the sensitivity to precipitation is calculated as 0.16 m w.e.a(-1) for a 10% change.