Arctic freshwater fluxes from earth observation data

Through both atmospheric and oceanic circulation, heat is transferred between the equator and the poles. Possible ways in which the Arctic ecological systems can be affected by warmer temperatures include: changes in amount and duration of snow and ice cover; frequency and extent of spring floods; changes in the ratio of precipitation minus evapotranspiration; amounts of water transport from lakes and rivers from snow and permafrost melting; and a decrease in frozen precipitation. A key component in transferring heat is through freshwater exchange in and out of the Arctic. Hence, accurate mapping freshwater fluxes and potentially its changes with time is vital to describe the heat transfer and its possible temporal changes. Our results demonstrate how ESA’s Earth Observation data together with in-situ measurements can be used to improve the mapping of the major Arctic Ocean freshwater fluxes. In this paper, we outline how four of the five major freshwater fluxes can be determined using present day Earth Observation data exclusively. These are: discharge from rivers; inflow through ice and melt run off; outflow of freshwater in sea ice; and in/outflow of freshwater through ocean currents. We subsequently present key finding and estimates of these four freshwater fluxes and compare our results with estimates based on in-situ data provided through previous studies.