A. Solomon, C. Heuzé, B. Rabe, S. Bacon, L. Bertino, P. Heimbach, J. Inoue, D. Iovino, R. Mottram, X. Zhang, Y. Aksenov, R. McAdam, A. Nguyen, R. Raj, and H. Tang (2021) Freshwater in the Arctic Ocean 2010-2019, Ocean Science, vol 17, pp. 1081–1102, doi:10.5194/os-17-1081-2021.
This is a review paper that aimed at determining how the Arctic Ocean freshwater content has changed over the last decade, and why.
Disclaimer: In oceanography, “salt content” is preferable to “freshwater content”, as the latter is based on a somewhat arbitrary choice of reference salinity. However, the vast majority of the published literature still uses freshwater content, as do other fields such as glaciology. Therefore, for this review, we used freshwater content as well.
Our main findings are:
- Freshwater content increased over 2000-2009 but appears to have stabilised over 2010-2019.
- This stabilisation is the result of an increase in freshwater content over the Beaufort Gyre and a decrease over the rest of the Arctic.
- The atmospheric contribution is controlled by the Arctic Oscillation (more moisture transport to the Arctic during a positive phase).
- The Arctic sea ice has transitioned to a new state: seasonal cover over the shelves, fast transpolar drift. No clear conclusion on the impact of this new sea ice on the ocean and atmosphere in the literature yet.
- Mass loss from Greenland and other Arctic glaciers has increased.
- Vertical mixing in the ‘Atlantified’ Arctic has increased and the halocline has weakened.
Our most notable conclusion is that all components of the Arctic climate system, especially rivers, are still unsufficiently monitored to clearly distinguish climate change signal from low frequency variability.