Accelerated contributions of Canada's Baffin and Bylot Island glaciers to sea level rise over the past half century

Abstract

Abstract. Canadian Arctic glaciers have recently contributed large volumes of meltwater to the world's oceans. To place recently observed glacier wastage into a historical perspective and to determine the region's longer-term (∼50 years) contribution to sea level, we estimate mass and volume changes for the glaciers of Baffin and Bylot Islands using digital elevation models generated from airborne and satellite stereoscopic imagery and elevation postings from repeat airborne and satellite laser altimetry. In addition, we update existing glacier mass change records from GRACE satellite gravimetry to cover the period from 2003 to 2011. Using this integrated approach, we find that the rate of mass loss from the region's glaciers increased from 11.1 ± 3.4 Gt a −1 (271 ± 84 kg m −2 a −1 ) for the period 1963-2006 to 23.8 ± 6.1 Gt a −1 (581 ± 149 kg m −2 a −1 ) for the period 2003-2011. The doubling of the rate of mass loss is attributed to higher temperatures in summer with little change in annual precipitation. Through both direct and indirect effects, changes in summer temperatures accounted for 70-98 % of the variance in the rate of mass loss, to which the Barnes Ice Cap was found to be 1.7 times more sensitive than either the Penny Ice Cap or the region's glaciers as a whole. This heightened sensitivity is the result of a glacier hypsometry that is skewed to lower elevations, which are shown to have a higher mass change sensitive to temperature compared to glacier surfaces at higher elevations. Between 2003 and 2011 the glaciers of Baffin and Bylot Islands contributed 0.07 ± 0.02 mm a −1 to sea level rise accounting for 16 % of the total contribution from glaciers outside of Greenland and Antarctica, a rate much higher than the longer-term average of 0.03 ± 0.01 mm a −1 (1963 to 2006).

Circum-Arctic Changes in the Flow of Glaciers and Ice Caps from Satellite SAR Data between the 1990s and 2017

“…Annual precipitation is low, ranging from 400 mm in the south to less than 100 mm in the centre. Because there is generally low interannual variability in precipitation and high variability in melt production, interannual variability in the regional surface mass budget is largely governed by changes in the summer surface air temperatures [10]. Since the late 1980s, and especially since 2005, changing summer atmospheric circulation patterns have increased advection of warm air from the north-west Atlantic to the Canadian High Arctic, leading to increased surface melt and longer melt seasons.…”

“…By reason of the large potential contribution of Arctic GIC to sea level and the already observed increased mass loss for some of the Arctic islands (e.g., [9,10]) several studies have recently investigated flow velocities, changes in velocity, and also elevation changes from altimetry for numerous Arctic GIC in great detail. For example, over the Canadian Arctic [11] analysed velocities of the Devon Ice Cap, Van Wychen, W. et al [12] presented flow velocities and discharge for all of the glaciers and ice caps on Baffin and Bylot islands, and Van Wychen, W. et al [13] studied multi-temporal trends in velocity and discharge for Ellesmere and Axel Heiberg Islands.…”

Glacier Surface Velocity Retrieval Using D-InSAR and Offset Tracking Techniques Applied to Ascending and Descending Passes of Sentinel-1 Data for Southern Ellesmere Ice Caps, Canadian Arctic

“…Finally, many research papers indicate a clear increase in ice mass losses and associated contribution of Canadian Arctic glaciers to sea-level rise during recent years. This increase in mass loss is mostly caused by surface melt and runoff, and not by glacier dynamics [38][39][40][41]45].…”

Recent changes in area and thickness of Torngat Mountain glaciers (northern Labrador, Canada)

“…Examination of Torngat glacier change may provide insights into the deglaciation dynamics of other similarly situated small-glacier populations (e.g. around the south Greenland ice sheet peripheries and Canadian Arctic Archipelago; Nilsson et al, 2015;Gardner et al, 2012) and other small glaciers retreating into cirque basins in temperate high-mountain settings (e.g. European Alps and Pyrenees, North American Rockies and Cascade Mountains).…”

“…Whilst early exploration and reconnaissance survey flights led to classification and mapping of some Labrador glaciers (e.g. Forbes, 1938;Henoch and Stanley, 1968), a complete inventory and analysis of the glaciers of the Torngat Mountains, covering a total active glacier area in 2005 of 22.5 ± 1.8 km 2 (not including relict ice), has only recently been completed and incorporated into global glacier datasets (Way et al, 2014;Pfeffer et al, 2014;Arendt et al, 2015). Combining the new regional glacier inventory (Way et al, 2014) with field-and remote-sensing-based analyses, Way et al (2015) showed a consistent glacial response to centennial-scale regional climate warming by documenting a 52.5 % reduction in ice extent since glaciers reached their Little Ice Age (LIA) maxima (dated to between 1581 and 1673).…”