Impact of the sea ice accelerated melting on the velocity structure of the East Greenland Current

Details

Supervisors

Fichefet, Thierry ; Ponsoni, Leandro

Faculty

Faculté des sciences

Degree label

Master [120] en sciences physiques, à finalité approfondie

Abstract

The East Greenland Current (EGC) flows along the east coast of Greenland, connecting the Arctic and Atlantic Oceans. This current is characterized by zonal density gradients, indicative of a baroclinic component. The EGC transports sea ice from the Arctic Ocean, which melts along its path, releasing low salinity water at the ocean's surface. With ongoing global warming, which is particularly pronounced in the Arctic region, the extent of sea ice has experienced a substantial reduction. In this master's thesis, we examine the impact of accelerated sea ice melting on the velocity structure of the EGC. We investigate how changes in sea ice melt alter the release of low salinity water at the ocean's surface and consequently affect the baroclinic component of the EGC. Utilizing the Ocean Reanalysis System v5 (ORAS5) from the European Centre for Medium-Range Weather Forecasts, we first validate this dataset against various observational data over the period from January 2011 to December 2018. During this period, we observe a weakening of the northern part of the EGC and a strengthening in the south. By computing zonal density gradients and employing the dynamical method, we demonstrate that these observed changes are partially attributed to variations in the baroclinic component, particularly evident in the northern region. We find that alterations in density profiles are due to an increase in salinity along the east coast of Greenland. Furthermore, we present evidence suggesting a potential causal relationship between the decline in sea ice melt over the region and the subsequent rise in salinity. Finally, we establish a correlation between decreasing sea ice transport through Fram Strait and diminishing sea ice melt in the EGC region, indicating a foreseeable trajectory for its future evolution.