Reanalysing the 2007–19 glaciological mass-balance series of Mera Glacier, Nepal, Central Himalaya, using geodetic mass balance
Patrick Wagnon, Fanny Brun, Arbindra Khadka, Étienne Berthier, Dibas Shrestha, Christian Vincent, Yves Arnaud, Delphine Six, Amaury Dehecq, Martin Ménégoz, Vincent Jomelli
Abstract
Abstract The 2007–19 glaciological mass-balance series of Mera Glacier in the Everest Region, East Nepal, is reanalysed using the geodetic mass balance assessed by differencing two DEMs obtained from Pléiades stereo-images acquired in November 2012 and in October 2018. The glaciological glacier-wide annual mass balance of Mera Glacier has to be systematically decreased by 0.11 m w.e. a −1 to match the geodetic mass balance. We attribute part of the positive bias of the glaciological mass balance to an over-estimation of the accumulation above 5520 m a.s.l., likely due to a measurement network unable to capture its spatial variability. Over the period 2007–19, Mera Glacier has lost mass at a rate of −0.41 ± 0.20 m w.e. a −1 , in general agreement with regional averages for the central Himalaya. We observe a succession of negative mass-balance years since 2013.