Investigating the impact of glacial meltwater plumes in Greenland's Fjords

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Global climate change will disproportionately affect the polar regions. Warmer atmospheric and ocean temperatures will increase ice melt from polar regions, which will contribute to global sea level rise. The Greenland Ice Sheet meets the ocean in Greenland's fjords, where warm ocean water can melt the front of marine-terminating glaciers ('tidewater glaciers'). To predict the rate and volume of future sea level rise more accurately, we need to understand how ocean properties affect the rate and volume of ice loss from the Greenland Ice Sheet. Ice-ocean interactions in Greenland's fjords are also important to understand because when fresh, buoyant meltwater from the glaciers enters the ocean it changes the temperature and salinity of the surrounding water. This injection of fresh buoyant water will affect ocean circulation in Greenland's Fjords, and the physical properties of water exported onto the shelf from the fjords. Meltwater-induced changes in ocean circulation are important to understand, as ocean circulation is a global process that regulates the wider climate. One of the limitations of current global climate models is that they assume that the physical properties of the ocean in fjords are the same as on the shelf. However, observations show that this is not the case. This project aims to improve our understanding of how meltwater exported from the Greenland Ice sheet in subglacial meltwater plumes affects the physical ocean properties in Greenland's fjords by: (i) collating Greenland-wide observations of fjord water properties vs adjacent shelf water properties; (ii) running experiments on a well-developed plume model to understand the degree to which glacial meltwater plumes are responsible for the modification of ocean water properties in fjords across Greenland; (iii) studying how the effect of these plumes varies throughout the melt season and with distance along the fjord using MITgcm, a state-of-the-art global circulation model.