The Campos confguration
comparison with drifter data
and current module (top) and
weather conditions (although
cloud cover can be an issue).
Satellite data time coverage is
also better, as the data are often
continuous, with time series
going back as far as 20 years.
In addition, the resolution of
satellite data is very high and
able to reach down to a few
meters for synthetic aperture
radar imagery, although it is
often in the range of a few kilometers for most products.
Furthermore, the near-real-time
delivery of the data takes a few
hours, which is quicker than
the characteristic time scales of
many ocean phenomena.
Two aspects of the data determine
its suitability for use by the HCS: quality and availability in real and near-real
time, and in forecast modes. Hence, if
consistent with the HCS���s needs, priority
is given to these data sets in operational
mode. There are three types of data used
in the production of the HCS currents.
Satellite Data. Satellite data are
used to provide information on the
large-scale circulation (altimetry data,
often from CLS���s Aviso Web server)
through the geostrophy calculation. It
is also used to give information on the
small-scale features, such as sea surface temperature and ocean color data,
through the surface quasigeostrophic
approach. Sea surface temperature and
ocean color data are operationally produced at CLS.
Model Data. Three types of model
data are used in the HCS: Ocean, atmospheric and tidal. Ocean model
data provide boundary conditions and
information on the large-scale veloc-
ity intensity distribution, often from
the Mercator Ocean (Ramonville-St.Agne) model but also from regional
models when available. These operational models use in-situ observation
and along-track satellite data, such as
Atmospheric data are used to calculate the wind-driven part of the
fow, often from the European Centre
for Medium-Range Weather Forecasts
(ECMWF) model and from available
Tidal model data from a global CLSrun tidal model gives the tidal currents.
In-Situ Data. Ocean in-situ data
from ADCPs, rotor current meters or
drifting foats are used to confgure
and validate an HCS confguration.
CLS has developed and maintains a
database of all available drifters��� data
from France���s Coriolis data center or
Argo foat program.
Atmospheric in-situ data can be
used by the HCS to determine the
wind-driven part of the circulation.
MARCH 2013 / st