Mass-balance observation, reconstruction and sensitivity of Stok glacier, Ladakh region, India, between 1978 and 2019
Mohd Soheb, AL. Ramanathan, Thupstan Angchuk, Arindan Mandal, Naveen Kumar, Sonam Lotus
Abstract
Abstract We present the first-ever mass-balance (MB) observation (2014–19), reconstruction (between 1978 and 2019) and sensitivity of debris-free Stok glacier (33.98°N, 77.45°E), Ladakh Region, India. In-situ MB was negative throughout the study period except in 2018/19 when the glacier witnessed a balanced condition. For MB modelling, three periods were considered based on the available data. Period I (1978–87, 1988/89) witnessed a near balance condition (−0.03 ± 0.35 m w.e. a −1 ) with five positive MB years. Whereas Period II (1998–2002, 2003–09) and III (2011–19) experienced high (−0.9 ± 0.35 m w.e. a −1 ) and moderate (−0.46 ± 0.35 m w.e. a −1 ) negative MBs, respectively. Glacier area for these periods was derived from the Corona, Landsat and PlanetScope imageries using a semi-automatic approach. The in-situ and modelled MBs were in good agreement with RMSE of 0.23 m w.e. a −1 , R 2 = 0.92, P < 0.05. The average mass loss was moderate (−0.47 ± 0.35 m w.e. a −1 ) over 28 hydrological years between 1978 and 2019. Sensitivity analysis showed that the glacier was more sensitive to summer temperature (−0.32 m w.e. a −1 °C −1 ) and winter precipitation (0.12 m w.e. a −1 for ± 10%). It was estimated that ~27% increase in precipitation is required on Stok glacier to compensate for the mass loss due to 1°C rise in temperature.