Geoscience Reference
In-Depth Information
Fig. 1 Monthly composites of the sea surface salinity at a spatial resolution of 0.5 9 0.5 deduced from
SMOS data (CATDS v2) for the months of March (Upper) and August (Lower) 2010
2 Data
A range of satellite and in situ data sets are used in the present study with focus on the
years 2010-2012 following the SMOS launch date. The data products are described below.
2.1 SMOS SSS Data
SMOS (Soil Moisture and Ocean Salinity) is the European Space Agency (ESA)'s water
mission (Kerr et al.
2010
; Mecklenburg et al.
2012
), an Earth Explorer Opportunity
Mission approved under the Living Planet Program. SMOS was launched in November
2009, and the technical approach developed to achieve adequate radiometric accuracy, as
well as spatial and temporal resolution compromising between land and ocean science
requirements, is polarimetric interferometric radiometry (Ruf et al.
1988
; Font et al.
2010
)
at L-band (frequency of *1.4 GHz). ESA produces so-called level 2 SSS, or L2 products,
which correspond to instantaneous SSS retrievals under the satellite swath.
In the present study, level 2 SMOS SSS are from the first SMOS/ESA annual repro-
cessing campaign in which ESA level 1 v5.04 and level 2 v5.50 processors have been used.
In these versions, significant improvements with respect to the flaws discovered in the first
