Contrasted surface mass balances of debris-free glaciers observed between the southern and the inner parts of the Everest region (2007–15)

摘要: Three debris-free glaciers with strongly differing annual glaciological glacier-wide mass balances (MBs) are monitored in the Everest region (central Himalaya, Nepal). The budget of Mera Glacier (5.1 km2 2012), located southern part this region, was balanced during 2007–15, whereas Pokalde (0.1 2011) and West Changri Nup (0.9 2013), ~30 km further north, have been losing rapidly MBs −0.69 ± 0.28 m w.e. a−1 (2009–15) −1.24 0.27 (2010–15), respectively. An analysis high-elevation meteorological variables reveals that these sensitive to precipitation, occasional severe cyclonic storms originating from Bay Bengal. We observe a negative horizontal gradient precipitation south-to-north direction across range (≤−21 mm km−1, i.e. −2% km−1). This contrasted mass-balance pattern over rather short distances is related (i) low maximum elevation glaciers, resulting years where their accumulation area ratio reduced zero (ii) steeper vertical MB for inner arid range.