Using reconstructed Irminger Water changes within the past three decades to connect the West Greenland shelf to the production of Labrador Sea Water

In this study we analyze the exchange processes between the West Greenland shelf and the Labrador Sea. This region is affected by warm and saline waters originating from the subtropical North Atlantic, as well as cold and fresh waters from the Arctic and the Greenland Ice Sheet. Heat and freshwater both impact the local formation of Labrador Sea Water (LSW) that itself is a major contributor to the Atlantic Meridional Overturning Circulation.

We use the ARMOR3D large-scale hydrographic data set from the Copernicus Marine Environmental Monitoring Service (CMEMS) and validate it with ship-based measurements in the period between 1993 to 2018. By extracting cross-shelf sections from ARMOR3D for various locations around Greenland, we reconstruct time series of local water masses like the Irminger Water (IW) for the past three decades. Previous studies from the West Greenland shelf have shown that IW properties are locally anti-correlated to changes in LSW. We analyze the interannual and decadal variability of these IW time series and compare them towards hydrographic changes observed in the interior Labrador Sea.

Since ARMOR3D allows us to investigate interannual and decadal changes along cross-shelf sections, the goal of this study is to unravel the complex connection between changes in the shelf regions around Greenland and the interior Labrador Sea, especially the local water mass production.