Labsea Melt II: Estimates of submarine melt water from Greenland: a driver for sea level changes

figures 1 and 2: Iceberg near Greenland (Photo O. Huhn)
figure 3: Drift ice near Greenland (Photo M. Rhein).
  • Mass loss from the Greenland Ice Sheet increased significantly over the past two decades. Besides the growing influence on sea level rise, the pathways and the amount of melt water imported into the interior of the ocean could have crucial consequences for the ventilation and formation of deep water and, hence, the strength of the climate-relevant Atlantic meridional overturning circulation and, hereafter, the local sea level.
  • The main result of the first phase was, that for the first time, submarine melt water from Greenland was unambiguously identified outside of fjords. Melt water is highest in the upper 300m confined to the Greenland and Canadian slope and shelf. The strong dilution of melt water in the upper ocean and it’s relatively small percentages indicate that melt water is not a main player for deep water formation yet. The mechanism leading to the episodic occurrence of melt water in the deep water masses is uncertain. It could herald episodic East Greenland Current spill jets events that contains melt water.
  • Using oceanic helium and neon observations in a far larger data set, which is available since 2018, we want to investigate the melt water distribution near Greenland marine terminating glaciers, in the East Greenland Current, in the Labrador and in the Irminger Sea and in the source regions of the East Greenland Current spill jets. Are there more events in the newer data sets? How much melt water needs to be present on which key locations to significantly influence formation and ventilation of the relevant water masses.