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: MORTIMER, COLLEEN A., SHARP, MARTIN, VAN WYCHEN, WESLEY
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2018
• Subjects: Earth-Surface Processes; Arctic; Journal of Glaciology; Queen Elizabeth Islands
• Online Access: http://dx.doi.org/10.1017/jog.2018.37; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143018000370

ABSTRACT 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 (d h /d t ) 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 d h /d t 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.