Abstract

ABSTRACTCanada's Queen Elizabeth Islands (QEI) contain ~14% of the world's glacier and ice-cap area. Sparse in-situ measurements indicate that interannual variability in glacier surface mass balance in this region is driven primarily by variations in summer melt, and that the annual surface mass balance of four index glaciers has become increasingly negative since 2007. Here, we use a 16-a record of satellite-derived mean summer (June–August) land surface temperatures (LST) from NASA's Moderate Resolution Imaging Spectroradiometer to investigate large-scale spatial and temporal variability in the duration and intensity of summer melt across glaciated surfaces in the QEI from 2000 to 2015. During this period, QEI mean summer glacier surface temperatures increased at an average rate of 0.06 ± 0.04°C a−1, for a total of nearly 1°C. Most of this increase occurred between 2005 and 2012, when mean summer near-surface (2 m) and upper-air (700 hPa) temperatures were 1.0–1.2°C higher than the 1948–2015 mean. There is a strong correlation between the glacier LST and 700 hPa air temperature records (r> 0.8). The period 2005–12, when mean summer LSTs were anomalously high, was likely the warmest period in the region since at least 1948.

Highlights

  • 2011–15 was the warmest 5-a period on record

  • In situ and remote sensing measurements, combined with modeling of the mass balance of glaciers in Canada’s Queen Elizabeth Islands (QEI; 74.5–83.5° N, 61–121°W), a region that contains ∼14% of the global glacier area, show that the rate of mass loss from these glaciers nearly tripled between 2004–06 and 2007–09 (Gardner and others, 2011)

  • The mean summer glacier land surface temperatures (LST) for each of the eight regions shown in Figure 1c was computed by averaging the mean summer LSTs (Fig. 2) for all glaciated pixels within each region

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Summary

Introduction

2011–15 was the warmest 5-a period on record. Global mean annual air temperatures from 2006 to 2010 and 2011 to 2015 were respectively 0.51 and 0.57°C above the 1961–90 mean (World Meteorological Organization Provisional Statement, 25 November 2015). Global air temperature increases are enhanced at high latitudes. In situ and remote sensing measurements, combined with modeling of the mass balance of glaciers in Canada’s Queen Elizabeth Islands (QEI; 74.5–83.5° N, 61–121°W), a region that contains ∼14% of the global glacier area, show that the rate of mass loss from these glaciers nearly tripled between 2004–06 and 2007–09 (Gardner and others, 2011). Other modeling studies indicate rates of glacier mass loss from the QEI of between 46 ± 5 and 37 ± 10 Gt a−1 from 2003 to 2011 (Lenaerts and others, 2013). As a result of 21st-century warming and accelerated mass wastage, glaciers in the Canadian Arctic have become the largest regional contributor to the eustatic component of global sea level rise outside the major ice sheets (Gardner and others, 2013; Radić and others, 2014)

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