More than skin deep: sea surface temperature as a means of inferring Atlantic Water variability on the southeast Greenland continental shelf near Helheim Glacier
Journal Article
Outlet glaciers account for almost half of the Greenland Ice Sheet’s; mass loss since 1990. Warming subsurface Atlantic Water (AW) has been; implicated in much of that loss, particularly along Greenland’s; southeastern coast. However, oceanographic observations are sparse prior; to the last decade, making it difficult to diagnose changes in AW; properties reaching the glaciers. Here, we investigate the use of sea; surface temperatures (SST) to quantify ocean temperature variability on; the continental shelf near Sermilik Fjord and Helheim Glacier. We find; that after removing the short-term, atmospheric-driven variability in; non-winter months, regional SSTs provide a reliable upper ocean; temperature record. In the trough region near Sermilik Fjord, the; adjusted SSTs correlate well with moored ocean measurements of the water; entering the fjord at depth and driving glacier melting. Using this; relationship, we reconstruct the AW variability on the shelf dating back; to 2000, eight years before the first mooring deployments. Seasonally,; AW reaches close to the fjord’s mouth in fall and winter and further; offshore in spring. Interannually, the AW temperatures in the trough do; not always track properties in the source waters of the Irminger; Current. Instead, the properties of the waters found at the fjord mouth; depend on both variations in the source AW and, also, in the Polar Water; that flows into the region from the Arctic Ocean. Satellite-derived; SSTs, although dependent on local oceanography, have the potential to; improve understanding around previously unanswered glacier-ocean; questions in areas surrounding Greenland and Antarctica.
