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

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.

Attributing Greenland Warming Patterns to Regional Arctic Sea Ice Loss

“…A wide range of approaches have previously indicated that Baffin Bay sea ice changes impact conditions on Greenland. Rennermalm et al () and Stroeve et al () present process‐based analyses linking sea ice loss through changed surface fluxes to increased melt on GrIS. In agreement with the signals we see along the west coast (Figure ), both of these studies find that sea ice loss in Baffin Bay promotes melting on the adjacent parts of the ice sheet.…”

“…The long-term view employed here is inspired by detection and attribution studies used, for example, in the context of the Intergovernmental Panel on Climate Change (Bindoff et al, 2013). It is meant to supplement process-based analyses (e.g., Rennermalm et al, 2009;Stroeve et al, 2017), attempting to reveal covariability between changes in different parts of Greenland and the state of the sea ice cover and the state of the global climate, respectively.…”

“…expectation that sea ice loss is a key contributor to amplified Arctic warming (Dai et al, 2019;Screen & Simmonds, 2010;Serreze & Barry, 2011), the still short observational record of the Arctic sea ice cover change makes it challenging to show direct links between sea ice loss and warming over Greenland. Previous studies have focused on process-based attribution using lagged correlations to trace the sequence of events from sea ice reduction to increased warming or melt on the ice sheet (e.g., Ballinger et al, 2018;Rennermalm et al, 2009;Stroeve et al, 2017). Here, we use a linear framework, aiming to separate the simulated warming in two contributions: one following the global warming trend and one following the Arctic sea ice conditions.…”

Present‐Day Greenland Ice Sheet Climate and Surface Mass Balance in CESM2

“…In summer, the polar vortex is slightly weaker in CESM2, with its central geopotential height overestimated by 2 dams (Figure f), although the southward expansion of the polar vortex appears exaggerated. September sea ice extent is slightly underestimated in CESM2 (Figure e), but there is good agreement near Greenland, suggesting that substantial GrIS SMB biases due to sea ice biases are unlikely (Noël et al, ; Stroeve et al, ).…”

The Expanding Footprint of Rapid Arctic Change

“…For example, sea ice loss is projected to continue, including periods of especially rapid change (e.g., Holland et al, 2006; rapid declines already occurred in 2007 and 2012; Stroeve et al, 2012). Rapid sea ice loss not only heightens atmospheric warming, but also early loss of sea ice locally near the Greenland Ice Sheet may increase heat transfer from the ocean to the atmosphere above the ice sheet and result in increased ice sheet melt (Stroeve et al, 2017). Rapid sea ice loss also has a significant effect on temperatures over land with implications for permafrost thaw (Lawrence et al, 2008), and increased wave activity due to sea ice loss can also lead to stronger permafrost coastal erosion, further exacerbated by sea level rise from land ice loss (Fritz et al, 2017).…”