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| Titel |
Testing SMOS Salinity Retrievals against surface salinity observations in the North Atlantic Ocean |
| VerfasserIn |
Julia Köhler, Detlef Stammer, Meike Sena Martins, Detlef Quadfasel |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075567
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| Zusammenfassung |
| Since January 2010 the ESA Soil moisture and ocean salinity mission (SMOS) provides
salinity data of the sea surface (SSS). Those measurements offer the possibility to better
observe and understand SSS variations over the global ocean. However, an important step for
any new measurement technology is to test and improve those measurements through
comparisons against in situ measurements. For space based SSS measurements this is
particularly important in high latitudes where uncertainties are highest due to the
reduced sensitivity of the emissivity (brightness temperature) to surface salinity
variations. In this paper we test SMOS salinities against surface salinity observations
obtained during a series of cruises of German research vessels in the Nordic Seas. We
analyze the differences of SMOS and TSG data with respect to the distance to the
coast, temporal variability, as well as to the surface temperature and to the water
depth. Although absolute SMOS salinities show biases, the spatial structures of the
salinity variations are very similar in both data sets. SMOS data are most of the
time too fresh with respect to in situ data. Especially in areas of higher SSS the
average bias is -2 -g
kg. This too fresh bias could be caused by a remaining land
contamination in the SMOS data.However, some local differences- particularly around the
front of freshwater from the Greenland shelf- can clearly be attributed to temporal
variability of the position of this front. Within the frontal zone, the SMOS salinities
are higher than the TSG salinities, and the SSS gradient in the TSG data is more
distinct. This is due to the monthly and spatially averaging of the SMOS product. |
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