Long-term annual and seasonal mass balance reconstruction and sensitivity analysis of Chhota Shigri Glacier in Western Himalaya.

Glaciers, in general, are sensitive to changes in the climate but Himalayan glaciers, in particular, are highly affected by climate change. Mass balance (MB) of glaciers is one of the important parameters to examine the response of glaciers to climate variability and change. The study of mass balance sensitivity (MBS) due to climate perturbations for glaciers is also important to understand future behavior of the glaciers. For Chhota Shigri Glacier, research on the estimation of long-term annual and seasonal MB and MBS as well as equilibrium-line altitude (ELA) and accumulation area ration (AAR) sensitivity analysis is not reported in detail. Accordingly, the present study carries out a detailed analysis of annual and seasonal MBS from 1953 to 2014 using annual and monthly climate perturbations as well as ELA and AAR sensitivities for the Chhota Shigri Glacier. The long-term annual and seasonal MB of Chhota Shigri Glacier from 1953 to 2014 is reconstructed using distributed temperature-index model by simulating minimal model parameters, namely melt factor, snow, and ice radiations using Monte-Carlo simulation. The mean annual MB of Chhota Shigri was -0.28 ± 0.41 m w.e./year during 1953-2014. The annual MB decreased from - 0.09 ± 0.41 m w.e./year (1953-1968) to - 0.57 ± 0.41 m w.e./year (2000-2014). The estimated MBS of Chhota Shigri Glacier is 0.57 m w.e./°C due to temperature change which is high and can be attributed to the presence of significantly less debris-covered ice in Chhota Shigri Glacier. It is analyzed that ELA and AAR of Chhota Shigri Glacier will change to + 107.7 m a.s.l. and - 15.03% respectively due to increase in temperature by + 1 °C. Further, ~ 38% more precipitation is required to compensate for the change in MB, ELA and AAR which will occur due to + 1 °C temperature rise. The findings of the present study will also support the estimation of future MB of Chhota Shigri Glacier using minimal simulated model parameters for distributed temperature-index model which have been found to produce good results using long term high resolution climate data.