Ocean currents conveying large volumes of water can transport heat to great distances, through which they influence the climate. This is particularly true for the Arctic and the North Atlantic, the regions where water circulation has a significant impact on the atmosphere as well as on key oceanic processes. These processes are often sensitive to density stratification of ocean water, which is greatly shaped by salinity, or in another measure, by freshwater storage. Freshwater in the oceans is thus of particular importance.
Being connected by a network of currents, the Arctic and North Atlantic oceans exchange a large volume of water of different characteristics. As a consequence, their freshwater budgets are also connected. However, these budgets show spatial and temporal variations, and the fluxes between them cannot be considered constant either. The freshwater system of the Arctic linked to the North Atlantic is dynamic with changes and anomalies on different time scales, and the changes of this joint system seem to follow the evolution of atmospheric forcing patterns. Previous modeling results suggest the importance of wind stress forcing over key regions such as the Beaufort Sea or the Greenland Sea in influencing the distribution of freshwater.
In this study we examine the reaction of this linked freshwater system to changes in wind stress forcing through numerical experiments using the Modini-system, a partial coupling technique that allows flexible experiments with prescribed wind stress fields for the ocean in the otherwise fully coupled Earth System Model of the Max Planck Institute. The aim of this work is to investigate the role of atmospheric forcing in shaping freshwater reservoirs and exchanges between different subregions of the Arctic and North Atlantic oceans by calculating and analyzing climate response functions to changes in wind forcing over key regions.
EPIC Alfred Wegener Institut