The influence of sea surface salinity information when reconstructing ocean currents. The case of freshwater fluxes in the Arctic Sea.

Marta Umbert1, Estrella Olmedo2, Cristina González-Haro2, Justino Martínez2, Jordi Isern-Fontanet2 and Antonio Turiel2, (1)Barcelona Expert Center, Institute of Marine Sciences, CSIC, Physical and Technological Oceanography, Barcelona, Spain, (2)Institute of Marine Sciences, CSIC, Physical and Technological Oceanography, Barcelona, Spain
Abstract:
This study focus in the Arctic Ocean, identified as a hotspot of climate change. Hotspot regions refer to most responsive regions to climate change based on the changes of regional mean and interannual variability of precipitation and air temperature (Giorgi 2006). In the Arctic Ocean, adding satellite SSS information could potentially provide better estimates of surface currents, as SSS dominates surface buoyancy in specific seasons and therefore density, as they both are inversely proportional to each other.

Salinity has a major importance in the regional dynamics in the upper Arctic Ocean, where the hydrography is changing as seen in observational and modeling studies (Haine 2015). An increment of the global mean annual temperature should induce an increase in the discharge of Arctic rivers (Mulligan 2010). In particular, an increase of liquid freshwater content over both the Canadian Basin and the central Arctic Ocean has been observed (Rabe 2014). However, the precise impact of an increase of the Arctic freshwater runoff remains unclear.

SMOS SSS maps developed at Barcelona Expert Center at high latitudes (Olmedo 2018) are used to study the correlation between SST, SSH and SSS anomalies. We analyse the effective spatial and temporal resolutions of the different satellite variables, in order to better understand the dynamical processes that are being described by each one. We asses where and when SSS has a key role in ocean dynamics and would allow to provide better estimates of ocean currents. We demonstrate how the information of SSS enhance our understanding of the dynamics in the Arctic Ocean, where fresh water fluxes are of major importance.

Giorgi, F. 2006. Climate change hot-spots, Geophys. Res. Lett. 33, L08707.

Haine, T. et al. 2015. Arctic freshwater export: Status, mechanisms, and prospects, Global and Planetary Change, 125, 13 – 35.

Mulligan, R. P., et al. 2010. Dynamics of the Mackenzie River plume on the inner Beaufort shelf during an open water period in summer, Estuarine, Coastal and Shelf Science, 89(3), 214 – 220.

Rabe, B., et al. 2014. Arctic Ocean basin liquid freshwater storage trend 1992- 2012, GRL, 41(3), 961–968.

Olmedo, Estrella, et al. 2018. Seven Years of SMOS sea surface salinity at high latitudes: Variability in Arctic and Sub-Arctic Regions. Remote Sensing 10.11 (2018): 1772.