Aquarius Maps: Sea Surface Salinity at High Latitudes

  • Sea surface salinity, January 1-8, 2015

    January 1-8, 2015

  • Sea surface salinity, January 8-15, 2015

    January 8-15, 2015

  • Sea surface salinity, January 15-22, 2015

    January 15-22, 2015

  • Sea surface salinity, January 22-29, 2015

    January 22-29, 2015

  • Sea surface salinity, January 29 - February 5, 2015

    January 29 - February 5, 2015

  • Sea surface salinity, February 5-12, 2015

    February 5-12, 2015

  • Sea surface salinity, February 12-19, 2015

    February 12-19, 2015

  • Sea surface salinity, February 19-26, 2015

    February 19-26, 2015

  • Sea surface salinity, February 26 - March 5, 2015

    February 26 - March 5, 2015

  • Sea surface salinity, March 5-12, 2015

    March 5-12, 2015

  • Sea surface salinity, March 12-19, 2015

    March 12-19, 2015

  • Sea surface salinity, March 19-26, 2015

    March 19-26, 2015

  • Sea surface salinity, March 26 - April 2, 2015

    March 26 - April 2, 2015

  • Sea surface salinity, April 2-9, 2015

    April 2-9, 2015

  • Sea surface salinity, April 9-16, 2015

    April 9-16, 2015

  • Sea surface salinity, April 16-23, 2015

    April 16-23, 2015

  • Sea surface salinity, April 23-30, 2015

    April 23-30, 2015

  • Sea surface salinity, April 30 - May 7, 2015

    April 30 - May 7, 2015

  • Sea surface salinity, May 7-14, 2015

    May 7-14, 2015

  • Sea surface salinity, May 14-21, 2015

    May 14-21, 2015

  • Sea surface salinity, May 21-28, 2015

    May 21-28, 2015

  • Sea surface salinity, May 28 - June 4, 2015

    May 28 - June 4, 2015

  • Credit

  • Credit

Slideshow: 2015 sea surface salinity maps of the Northern Hemisphere ocean (hover over images to pause the slideshow).

These weekly gridded maps are made using the Aquarius sea surface salinity retrievals. They were obtained with algorithms developed by the Calibration/Validation working group, and applied to the microwave (L-band, about 1.4 GHz) brightness temperature measurements along the spacecraft swath. These maps show sea surface salinity expressed in practical salinity unit (psu) in the Northern and Southern Hemispheres at latitudes higher than 50°. Blue colors represent lower salinity, whereas red colors represent higher salinity. The date shown on the images (below) is the first day of that weekly measurement.

Salinity can only be retrieved from space when the ocean is not covered by sea ice. Sea ice is frozen ocean water. It forms, grows, and melts according to the seasons, but some sea ice remains year round in certain regions of both the Arctic and Antarctic. When a significant fraction of sea ice is present in the Aquarius measurements, salinity cannot be retrieved accurately. These areas were masked on the maps. Other areas without data correspond to either a lack of observations due to orbit geometry and spacecraft maneuvers, or are coastal regions where salinity is inaccurate.

The data presented are a weekly gridded average of the swath data distributed by NASA's Physical Oceanography Distributed Active Archive Center (PO.DAAC) and provided by Ludovic Brucker (1,2) and Emmanuel Dinnat (1,3).

Aquarius Level-3 weekly polar-gridded data sets can be downloaded from the National Snow and Ice Data Center (NSIDC).

(1) NASA Goddard Space Flight Center, Cryospheric Sciences Lab, Greenbelt MD, USA
(2) Universities Space Research Association, Greenbelt MD, USA
(3) Chapman University, Orange CA, USA

Aquarius Retrieved Sea Surface Salinity in the Northern High-Latitude Ocean

When ocean surface salinity retrievals are possible in the Arctic Ocean, values are smaller than for other regions. One can also see that blue colors are usually present in the vicinity of the sea ice margin. This may result from sea ice contamination of the Aquarius measurements, and do not necessarily reflect a low salinity.

These maps also show the significant difference between the saltier Atlantic Ocean and the fresher Pacific Ocean. Ocean surface salinity in polar regions varies seasonally as ice freezes (i.e., leaving saltier water in the ocean) and melts (i.e., adding fresh water to the ocean).


Maps By Year:  2015 | 2014 | 2013 | 2012 | 2011
Sea surface salinity in the northern hemisphere
May 28, 2015
Sea surface salinity in the northern hemisphere
May 21, 2015
Sea surface salinity in the northern hemisphere
May 14, 2015
Sea surface salinity in the northern hemisphere
May 7, 2015
Sea surface salinity in the northern hemisphere
April 30, 2015
Sea surface salinity in the northern hemisphere
April 23, 2015
Sea surface salinity in the northern hemisphere
April 16, 2015
Sea surface salinity in the northern hemisphere
April 9, 2015
Sea surface salinity in the northern hemisphere
April 2, 2015
Sea surface salinity in the northern hemisphere
March 26, 2015
Sea surface salinity in the northern hemisphere
March 19, 2015
Sea surface salinity in the northern hemisphere
March 12, 2015
Sea surface salinity in the northern hemisphere
March 5, 2015
Sea surface salinity in the northern hemisphere
February 26, 2015
Sea surface salinity in the northern hemisphere
February 19, 2015
Sea surface salinity in the northern hemisphere
February 12, 2015
Sea surface salinity in the northern hemisphere
February 5, 2015
Sea surface salinity in the northern hemisphere
January 29, 2015
Sea surface salinity in the northern hemisphere
January 22, 2015
Sea surface salinity in the northern hemisphere
January 15, 2015
Sea surface salinity in the northern hemisphere
January 8, 2015
Sea surface salinity in the northern hemisphere
January 1, 2015

Aquarius Retrieved Sea Surface Salinity in the Southern High-Latitude Ocean

  • Sea surface salinity, January 1-8, 2015

    January 1-8, 2015

  • Sea surface salinity, January 8-15, 2015

    January 8-15, 2015

  • Sea surface salinity, January 15-22, 2015

    January 15-22, 2015

  • Sea surface salinity, January 22-29, 2015

    January 22-29, 2015

  • Sea surface salinity, January 29 - February 5, 2015

    January 29 - February 5, 2015

  • Sea surface salinity, February 5-12, 2015

    February 5-12, 2015

  • Sea surface salinity, February 12-19, 2015

    February 12-19, 2015

  • Sea surface salinity, February 19-26, 2015

    February 19-26, 2015

  • Sea surface salinity, February 26 - March 5, 2015

    February 26 - March 5, 2015

  • Sea surface salinity, March 5-12, 2015

    March 5-12, 2015

  • Sea surface salinity, March 12-19, 2015

    March 12-19, 2015

  • Sea surface salinity, March 19-26, 2015

    March 19-26, 2015

  • Sea surface salinity, March 26 - April 2, 2015

    March 26 - April 2, 2015

  • Sea surface salinity, April 2-9, 2015

    April 2-9, 2015

  • Sea surface salinity, April 9-16, 2015

    April 9-16, 2015

  • Sea surface salinity, April 16-23, 2015

    April 16-23, 2015

  • Sea surface salinity, April 23-30, 2015

    April 23-30, 2015

  • Sea surface salinity, April 30 - May 7, 2015

    April 30 - May 7, 2015

  • Sea surface salinity, May 7-14, 2015

    May 7-14, 2015

  • Sea surface salinity, May 14-21, 2015

    May 14-21, 2015

  • Sea surface salinity, May 21-28, 2015

    May 21-28, 2015

  • Sea surface salinity, May 28 - June 4, 2015

    May 28 - June 4, 2015

  • Credit

  • Credit

Slideshow: 2015 sea surface salinity maps of the Southern Hemisphere ocean (hover over images to pause the slideshow).

The Southern Ocean is an important source for deep water formations, and therefore the thermohaline circulation. Downwelling of upper layer water is induced by surface cooling and salt rejection during the formation and growth of sea ice. However, sea surface salinity retrieval in the Southern Ocean is challenging. There are strong winds, and the circulation in the Southern Ocean is dominated by the Antarctic Circumpolar Current, which is regarded as the largest World's ocean current. Salinity retrieval is less accurate for very rough sea surfaces. In addition, waters around Antarctica are cold. Aquarius measurements are less sensitive to salinity in cold waters. Finally, the presence of sea ice add an additional complexity to the monitoring of salinity in the high latitudes of the Southern Hemisphere.


Maps By Year:  2015 | 2014 | 2013 | 2012 | 2011
Sea surface salinity in the southern hemisphere
May 28, 2015
Sea surface salinity in the southern hemisphere
May 21, 2015
Sea surface salinity in the southern hemisphere
May 14, 2015
Sea surface salinity in the southern hemisphere
May 7, 2015
Sea surface salinity in the southern hemisphere
April 30, 2015
Sea surface salinity in the southern hemisphere
April 23, 2015
Sea surface salinity in the southern hemisphere
April 16, 2015
Sea surface salinity in the southern hemisphere
April 9, 2015
Sea surface salinity in the southern hemisphere
April 2, 2015
Sea surface salinity in the southern hemisphere
March 26, 2015
Sea surface salinity in the southern hemisphere
March 19, 2015
Sea surface salinity in the southern hemisphere
March 12, 2015
Sea surface salinity in the southern hemisphere
March 5, 2015
Sea surface salinity in the southern hemisphere
February 26, 2015
Sea surface salinity in the southern hemisphere
February 19, 2015
Sea surface salinity in the southern hemisphere
February 12, 2015
Sea surface salinity in the southern hemisphere
February 5, 2015
Sea surface salinity in the southern hemisphere
January 29, 2015
Sea surface salinity in the southern hemisphere
January 22, 2015
Sea surface salinity in the southern hemisphere
January 15, 2015
Sea surface salinity in the southern hemisphere
January 8, 2015
Sea surface salinity in the southern hemisphere
January 1, 2015
Publications
Brucker, L., Dinnat, E.P., and Koenig, L.S. (2014a). Weekly Gridded Aquarius L-band Radiometer/Scatterometer Observations and Salinity Retrievals Over the Polar Regions - Part 1: Product Description, The Cryosphere, 8, 905-913, doi:10.5194/tc-8-905-2014.
Brucker, L., Dinnat, E.P., and Koenig, L.S. (2014b). Weekly Gridded Aquarius L-band Radiometer/Scatterometer Observations and Salinity Retrievals Over the Polar Regions - Part 2: Initial Product Analysis, The Cryosphere, 8, 915-930, doi:10.5194/tc-8-915-2014.
Brucker, L., Dinnat, E.P., Picard, G., and Champollion, N. (2014c). Effect of Snow Surface Metamorphism on Aquarius L-Band Radiometer Observations at Dome C, Antarctica, IEEE Transactions on Geoscience and Remote Sensing, 52 (11), 1-10, doi: 10.1109/TGRS.2014.2312102.