An unexpected seasonal variability of salinity in the Beaufort Sea upper layer in 1996–1998
MetadataShow full item record
The salinity in the upper Beaufort Sea from the mixed layer to the thermocline layer was observed by drifting buoys from 1996 to 1998. The salinity in this depth range was lower in winter and higher in the summer, the exact opposite from what one would expect from the seasonal cycle of the freshwater flux associated with the ice melting/freezing and river runoff. In this study, we calculated the daily Ekman transport and upwelling velocity in the Beaufort Sea, using both satellite and buoy data. In fall and winter months, the offshore transport of low-salinity water from the coastal area toward the interior where the buoys were located was observed to be strong. This horizontal Ekman transport led to the freshening of the surface Ekman layer in the buoy location. The convergence of the Ekman transport resulted in a strong downwelling in the offshore regions, and so the halocline and thermocline were pushed downward. The downwelling then results in the freshening of the subsurface salinity as observed by buoys. Other processes, such as lateral advection, may have also played a role in the subsurface freshening. The lack of in situ observations needed to estimate the salinity gradient makes it difficult to assess more accurately the contribution from lateral advection. A scaling analysis using the salinity climatology suggests that the lateral salinity advection, though considerably smaller than the vertical one, may not be negligible.
Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): C05034, doi:10.1029/2004JC002716.
Showing items related by title, author, creator and subject.
Schulze, Lena M.; Pickart, Robert S. (American Geophysical Union, 2012-06-27)Data from a mooring array deployed from August 2002 to September 2004 are used to characterize differences in upwelling near the shelf break in the Alaskan Beaufort Sea due to varying sea ice conditions. The record is ...
Yang, Jiayan (American Geophysical Union, 2009-12-11)In this paper, we examine the seasonal and interannual to decadal variability of oceanic downwelling in the Beaufort Sea. The surface wind stress is the primary driver for variability in the upper Arctic Ocean and sea ice. ...
Seasonal variation of the Beaufort shelfbreak jet and its relationship to Arctic cetacean occurrence Lin, Peigen; Pickart, Robert S.; Stafford, Kathleen M.; Moore, G. W. K.; Torres, Daniel J.; Bahr, Frank; Hu, Jianyu (John Wiley & Sons, 2016-12-02)Using mooring time series from September 2008 to August 2012, together with ancillary atmospheric and satellite data sets, we quantify the seasonal variations of the shelfbreak jet in the Alaskan Beaufort Sea and explore ...