Weekly gridded Aquarius L-band radiometer/scatterometer observations and salinity retrievals over the polar regions – Part 2: Initial product analysis

Following the development and availability of Aquarius weekly polar-gridded products, this study presents the spatial and temporal radiometer and scatterometer observations at L band (frequency ~1.4 GHz) over the cryosphere including the Greenland and Antarctic ice sheets, sea ice in both hemisphere...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: L. Brucker, E. P. Dinnat, L. S. Koenig
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2014
Subjects:
geo
envir
Antarctic
Arctic
Greenland
The Antarctic
Antarc*
Ice Sheet
Sea ice
The Cryosphere
Online Access:https://doi.org/10.5194/tc-8-915-2014
http://www.the-cryosphere.net/8/915/2014/tc-8-915-2014.pdf
https://doaj.org/article/a95c2fa49f1d45d6bd507e3fc74ee425
Description
Summary:Following the development and availability of Aquarius weekly polar-gridded products, this study presents the spatial and temporal radiometer and scatterometer observations at L band (frequency ~1.4 GHz) over the cryosphere including the Greenland and Antarctic ice sheets, sea ice in both hemispheres, and over sub-Arctic land for monitoring the soil freeze/thaw state. We provide multiple examples of scientific applications for the L-band data over the cryosphere. For example, we show that over the Greenland Ice Sheet, the unusual 2012 melt event lead to an L-band brightness temperature (TB) sustained decrease of ~5 K at horizontal polarization. Over the Antarctic ice sheet, normalized radar cross section (NRCS) observations recorded during ascending and descending orbits are significantly different, highlighting the anisotropy of the ice cover. Over sub-Arctic land, both passive and active observations show distinct values depending on the soil physical state (freeze/thaw). Aquarius sea surface salinity (SSS) retrievals in the polar waters are also presented. SSS variations could serve as an indicator of fresh water input to the ocean from the cryosphere, however the presence of sea ice often contaminates the SSS retrievals, hindering the analysis. The weekly grided Aquarius L-band products used are distributed by the US Snow and Ice Data Center at http://nsidc.org/data/aquarius/index.html , and show potential for cryospheric studies.

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