Aquarius Maps: Sea Surface Salinity at High Latitudes

  • Sea surface salinity, August 25 - September 1, 2011

    August 25 - September 1, 2011

  • Sea surface salinity, September 1-8, 2011

    September 1-8, 2011

  • Sea surface salinity, September 8-15, 2011

    September 8-15, 2011

  • Sea surface salinity, September 15-22, 2011

    September 15-22, 2011

  • Sea surface salinity, September 22-29, 2011

    September 22-29, 2011

  • Sea surface salinity, September 29 - October 6, 2011

    September 29 - October 6, 2011

  • Sea surface salinity, October 6-13, 2011

    October 6-13, 2011

  • Sea surface salinity, October 13-20, 2011

    October 13-20, 2011

  • Sea surface salinity, October 20-27, 2011

    October 20-27, 2011

  • Sea surface salinity, October 27 - November 3, 2011

    October 27 - November 3, 2011

  • Sea surface salinity, November 3-10, 2011

    November 3-10, 2011

  • Sea surface salinity, November 10-17, 2011

    November 10-17, 2011

  • Sea surface salinity, November 17-24, 2011

    November 17-24, 2011

  • Sea surface salinity, November 24 - December 1, 2011

    November 24 - December 1, 2011

  • Sea surface salinity, December 1-8, 2011

    December 1-8, 2011

  • Sea surface salinity, December 8-15, 2011

    December 8-15, 2011

  • Sea surface salinity, December 15-22, 2011

    December 15-22, 2011

  • Sea surface salinity, December 22-29, 2011

    December 22-29, 2011

  • Sea surface salinity, December 29, 2011 - January 5, 2012

    December 29, 2011 - January 5, 2012

  • Credit

  • Credit

Slideshow: 2011 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
December 29, 2011
Sea surface salinity in the northern hemisphere
December 22, 2011
Sea surface salinity in the northern hemisphere
December 15, 2011
Sea surface salinity in the northern hemisphere
December 8, 2011
Sea surface salinity in the northern hemisphere
December 1, 2011
Sea surface salinity in the northern hemisphere
November 24, 2011
Sea surface salinity in the northern hemisphere
November 17, 2011
Sea surface salinity in the northern hemisphere
November 10, 2011
Sea surface salinity in the northern hemisphere
November 3, 2011
Sea surface salinity in the northern hemisphere
October 27, 2011
Sea surface salinity in the northern hemisphere
October 20, 2011
Sea surface salinity in the northern hemisphere
October 13, 2011
Sea surface salinity in the northern hemisphere
October 6, 2011
Sea surface salinity in the northern hemisphere
September 29, 2011
Sea surface salinity in the northern hemisphere
September 22, 2011
Sea surface salinity in the northern hemisphere
September 15, 2011
Sea surface salinity in the northern hemisphere
September 8, 2011
Sea surface salinity in the northern hemisphere
September 1, 2011
Sea surface salinity in the northern hemisphere
August 25, 2011

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

  • Sea surface salinity, August 25 - September 1, 2011

    August 25 - September 1, 2011

  • Sea surface salinity, September 1-8, 2011

    September 1-8, 2011

  • Sea surface salinity, September 8-15, 2011

    September 8-15, 2011

  • Sea surface salinity, September 15-22, 2011

    September 15-22, 2011

  • Sea surface salinity, September 22-29, 2011

    September 22-29, 2011

  • Sea surface salinity, September 29 - October 6, 2011

    September 29 - October 6, 2011

  • Sea surface salinity, October 6-13, 2011

    October 6-13, 2011

  • Sea surface salinity, October 13-20, 2011

    October 13-20, 2011

  • Sea surface salinity, October 20-27, 2011

    October 20-27, 2011

  • Sea surface salinity, October 27 - November 3, 2011

    October 27 - November 3, 2011

  • Sea surface salinity, November 3-10, 2011

    November 3-10, 2011

  • Sea surface salinity, November 10-17, 2011

    November 10-17, 2011

  • Sea surface salinity, November 17-24, 2011

    November 17-24, 2011

  • Sea surface salinity, November 24 - December 1, 2011

    November 24 - December 1, 2011

  • Sea surface salinity, December 1-8, 2011

    December 1-8, 2011

  • Sea surface salinity, December 8-15, 2011

    December 8-15, 2011

  • Sea surface salinity, December 15-22, 2011

    December 15-22, 2011

  • Sea surface salinity, December 22-29, 2011

    December 22-29, 2011

  • Sea surface salinity, December 29, 2011 - January 5, 2012

    December 29, 2011 - January 5, 2012

  • Credit

  • Credit

Slideshow: 2011 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
December 29, 2011
Sea surface salinity in the southern hemisphere
December 22, 2011
Sea surface salinity in the southern hemisphere
December 15, 2011
Sea surface salinity in the southern hemisphere
December 8, 2011
Sea surface salinity in the southern hemisphere
December 1, 2011
Sea surface salinity in the southern hemisphere
November 24, 2011
Sea surface salinity in the southern hemisphere
November 17, 2011
Sea surface salinity in the southern hemisphere
November 10, 2011
Sea surface salinity in the southern hemisphere
November 3, 2011
Sea surface salinity in the southern hemisphere
October 27, 2011
Sea surface salinity in the southern hemisphere
October 20, 2011
Sea surface salinity in the southern hemisphere
October 13, 2011
Sea surface salinity in the southern hemisphere
October 6, 2011
Sea surface salinity in the southern hemisphere
September 29, 2011
Sea surface salinity in the southern hemisphere
September 22, 2011
Sea surface salinity in the southern hemisphere
September 15, 2011
Sea surface salinity in the southern hemisphere
September 8, 2011
Sea surface salinity in the southern hemisphere
September 1, 2011
Sea surface salinity in the southern hemisphere
August 25, 2011
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.