Investigating the local-scale influence of sea ice on Greenland surface melt

Julienne C Stroeve,Asa Rennermalm,Linette N Boisvert,Marco Tedesco,John R Mioduszewski,David Robinson

doi:10.5194/tc-11-2363-2017

Abstract

Abstract. Rapid decline in Arctic sea ice cover in the 21st century may have wide-reaching effects on the Arctic climate system, including the Greenland ice sheet mass balance. Here, we investigate whether local changes in sea ice around the Greenland ice sheet have had an impact on Greenland surface melt. Specifically, we investigate the relationship between sea ice concentration, the timing of melt onset and open-water fraction surrounding Greenland with ice sheet surface melt using a combination of remote sensing observations, and outputs from a reanalysis model and a regional climate model for the period of 1979–2015. Statistical analysis points to covariability between Greenland ice sheet surface melt and sea ice within Baffin Bay and Davis Strait. While some of this covariance can be explained by simultaneous influence of atmospheric circulation anomalies on both the sea ice cover and Greenland melt, within Baffin Bay we find a modest correlation between detrended melt onset over sea ice and the adjacent ice sheet melt onset. This correlation appears to be related to increased transfer of sensible and latent heat fluxes from the ocean to the atmosphere in early sea ice melt years, increasing temperatures and humidity over the ice sheet that in turn initiate ice sheet melt.

Highlights

The shrinking sea ice cover is one of the most striking features of Arctic climate change (e.g., Stroeve et al, 2012; Serreze et al, 2007)
heterogeneous correlation (HC) maps reveal opposing signs of the correlations between the map pairs (Fig. 3 columns 1 and 2 and columns 3 and 4) indicating an anticorrelation, meaning that increased ice sheet melt extent covaries with decreased sea ice area
In June, sea ice concentration (SIC) in both the Baffin Bay/Davis Strait and the Beaufort Sea regions has strong correlations with ECGrIS (|r|>0.70), and Greenland ice sheet (GrIS) meltwater production is highly correlated with ECSIC for the majority of the unmasked ice sheet surface (Fig. 3b)

Summary

Introduction

The shrinking sea ice cover is one of the most striking features of Arctic climate change (e.g., Stroeve et al, 2012; Serreze et al, 2007). Since the late 1970s, the sea ice extent (SIE) has declined by more than 40 % in September, with smaller yet statistically significant negative trends in other months. These negative trends have been linked to the observed increases in atmospheric CO2, with the prospect of the Arctic Ocean becoming seasonally ice free before the middle of this century if current emission rates continue (Notz and Stroeve, 2016). Similar to the sea ice environment, an anthropogenic signal has been identified in the observed changes of GrIS surface mass balance (SMB) (Fyke et al, 2014b)

Methods

Results

Discussion

Conclusion