Estimating the annual accumulation of the Khumbu Glacier, Nepal, using weather station data

Abstract

Estimates of glacier accumulation are a vital part of determining annual glacier mass balance. Here, the annual accumulation of the Khumbu Glacier, Nepal, is estimated using data from a dense network of high-altitude weather stations in the Khumbu Valley, extending to the summit of Mount Everest. Observations of precipitation phase are used to refine methods of phase modelling using logistic regression in conjunction with weather station and precipitation gauge data. Seasonal temperature lapse rates and spatio-temporal patterns of precipitation are inferred from weather station data, and observed precipitation is adjusted for snow undercatch based on modelled precipitation phase and wind speed. These methods are then combined and distributed over the glacier surface to produce an overall estimate of seasonal and annual accumulation rates of the Khumbu Glacier.