Australia: The Land Where Time Began

A biography of the Australian continent 

Greenland – Oceanic Transport of Surface Meltwater from the Southern Greenland Ice Sheet

Over recent decades mass loss from the Greenland ice sheet has been accelerating. Fjord circulation and dynamics can be influenced by runoff of freshwater from melting ice (Straneo et al., 2011), and delivery of bioactive micronutrients to the ocean can also be influenced (Bhatia et al., 2013). There can also be climate implications that result from this because in the adjacent Labrador Sea stratification may influence deep convection and the strength of the Atlantic meridional overturning circulation (Fichefet et al., 2003). However, the fate of the meltwater in the ocean has remained unclear. In this paper Luo et al. report the results of their study in which they used a high-resolution ocean model to show that only 1-15 % of the surface meltwater runoff that originates from southwest Greenland is transported to the west. Contrasting with this, up to 50-60 % of the meltwater runoff that originates in southeast Greenland is transported to the west into the Labrador Sea, which leads to significant salinity and stratification anomalies long distances from the coast. In future climate scenarios doubling of meltwater runoff is predicted, which results in a more-than-double increase in the anomalies offshore that persists further into the winter. In offshore export of meltwater interannual variability is tightly related to variability in wind forcing. Future changes in the rates of mass loss and surface runoff that will probably impact the ocean differently, depending on the area of Greenland they originate in, are indicated by the new insight that meltwaters originating from the west coast and the east coast have different fates.

Sources & Further reading

Luo, H., R. M. Castelao, A. K. Rennermalm, M. Tedesco, A. Bracco, P. L. Yager and T. L. Mote (2016). "Oceanic transport of surface meltwater from the southern Greenland ice sheet." Nature Geosci 9(7): 528-532.