Mass and Energy Balance Estimation of Yala Glacier (2011-2017), Langtang Valley, Nepal

Six-year glaciological mass balance measurements, conducted at the Yala Glacier between November 2011 and November 2017 are presented and analyzed. A physically-based surface energy balance model is used to simulate summer mass and energy balance of the Yala Glacier for the 2012-2014 period. Cumulative mass balance of the Yala Glacier for the 2011-2017 period was negative at -4.88 m w.e. The mean annual glacier-wide mass balance was -0.81 +/- 0.27 m w.e. with a standard deviation of +/- 0.48 m w.e. The modelled mass balance values agreed well with observations. Modelling showed that net radiation was the primary energy source for the melting of the glacier followed by sensible heat and heat conduction fluxes. Sensitivity of mass balance to changes in temperature, precipitation, relative humidity, surface albedo and snow density were examined. Mass balance was found to be most sensitive to changes in temperature and precipitation.