Influence of recent warming and ice dynamics on glacier surface elevations in the Canadian High Arctic, 1995–2014

• Published in: Journal of Glaciology
• Main Authors: COLLEEN A. MORTIMER, MARTIN SHARP, WESLEY VAN WYCHEN
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2018
• Subjects: Arctic glaciology; glacier mass balance; laser altimetry; remote sensing; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Arctic; Journal of Glaciology; Queen Elizabeth Islands
• Online Access: https://doi.org/10.1017/jog.2018.37; https://doaj.org/article/ff003fa7b3c84e03a825e449f4dcaf9a

Repeat airborne laser altimetry measurements show widespread thinning (surface lowering) of glaciers in Canada's Queen Elizabeth Islands since 1995. Thinning rates averaged for 50 m elevation bins, were more than three times higher during the period 2005/06 to 2012/14 pentad than during the previous two pentads. Strongly negative thickness change (dh/dt) anomalies from 2005/06 to 2012/14, relative to the 1995–2012/14 mean, suggest that most of the measured thinning occurred during the most recent 5–6 year period when mean summer land surface temperatures (LSTs) were anomalously high and the mean summer black-sky shortwave broadband albedos (BSA) were anomalously low, relative to the 2000/01–15/16 period, and upper-air (700 hPa) and near surface (2 m) air temperatures were between 0.8°C and 1.5°C higher than 1995–2012 mean. Comparisons of dh/dt with mean summer LST and BSA measurements from the Moderate Resolution Imaging Spectroradiometer and with surface longitudinal strain rates computed from surface velocity fields derived from RADARSAT 1/2 and Landat-7 ETM + data suggest that surface elevation changes were driven mainly by changes in climate. An exception to this occurs along many fast-flowing outlet glaciers where ice dynamics appear also to have played an important role in surface elevation changes.