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Decadal‐Scale Climate Forcing of Alpine Glacial Hydrological Systems
Author(s) -
Lane S. N.,
Nienow P. W.
Publication year - 2019
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2018wr024206
Subject(s) - environmental science , glacier , snow , climatology , hydrograph , forcing (mathematics) , snowpack , glacial period , snowmelt , climate change , radiative forcing , atmospheric sciences , physical geography , geology , flood myth , oceanography , geography , geomorphology , archaeology
Quantification of climate forcing of glacial hydrological systems at the decadal scale is rare because most measurement stations are too far downstream for glacier impacts to be clearly detected. Here we apply a measure of daily hydrograph entropy to a unique set of reliable, high‐altitude gauging stations, dating from the late 1960s. We find a progressive shift to a greater number of days with diurnal discharge variation as well as more pronounced diurnal discharge amplitude. These changes were associated with the onset of rapid warming in the 1980s as well as declining end of winter snow depths as inferred from climate data. In glaciated catchments, lower winter snow depths reduce the magnitude and duration of snowpack buffering and encourage the earlier onset of glacier ice exposure, with associated lower surface albedo and more rapid melt. Together, these processes explain the increase in the observed intensity of diurnal discharge fluctuations.