International Polar Year 2007–2008 - WMO

Concordiasi project over Antarctica (no. 41)
Antarctica is operationally and climatologically
data sparse due to highly limited surface observing
facilities in the high southern latitudes. Satellite
measurements have the potential to fill these data
gaps, but they present their own unique challenges
and difficulties. This is true, in particular, of the data
provided by hyperspectral infra-red sounders such as
IASI (Infrared Atmospheric Sounding Interferometer).
These challenges must be overcome and errors need
to be reduced to produce accurate reanalyses for
climate studies that are based primarily on observed
conditions.
Within the framework of IPY, the Concordiasi project
(Rabier et al., 2010, www.cnrm.meteo.fr/concordiasi/)
makes innovative observations of the atmosphere
above Antarctica in order to:
• enhance the accuracy of weather prediction
and climate records in Antarctica through the
assimilation of in situ and satellite data, and
• improve our understanding of microphysical and
dynamical processes controlling the ozone content
of the polar air masses by quasi-Lagrangian observations
of ozone and particle content and improved
characterization of the polar vortex dynamics.
Concordia
and Dumont d’Urville
Additional
Regular
radiosoundings
Concordia
Frequent
radiosoundings
and instrumented tower
A major Concordiasi component is a field
experiment during the Austral springs of 2008, 2009
and 2010 (Fig. 2.1-10). The field activities in 2010 are
based on a constellation of up to 18 long duration
stratospheric balloons deployed from the McMurdo
station. Six of these balloons will carry GPS receivers
and in situ instruments measuring temperature,
pressure, ozone and particles. Twelve of the balloons
are capable of releasing dropsondes on demand for
measuring atmospheric parameters. In 2008 and
2009, radiosounding measurements were collected at
various sites, including the Concordia station.
The atmospheric temperature profiles over the
Antarctic plateau exhibit a very strong inversion at
the surface, with surface temperatures colder by up
to 20K than the lower troposphere, which is difficult
both to model and observe. During the Concordiasi
field campaign, special measurements were obtained
measuring the atmospheric profiles together with
surface parameters, synchronised with the track of
the European MetOp platform with the hyperspectral
IASI sensor onboard. They were then compared to IASI
measurements and to the outputs of the meteorological
model of Meteo-France, especially adjusted for this
area (Bouchard et al., 2010). The available in situ obser-
2008 2009 2010 2011
Preliminary Data Assimilation studies
Instrument preparation
IASI retrievals at Concordia
Boundary layer studies
Instrument preparation
Antarctic area
Stratospheric
super−pressure balloons
Flight level instruments
meteorological sensors
ozone sensors
particle counter
GPS receivers
Dropsondes
Targeting dropsondes
IASI retrievals at dropsonde locations
Evaluation of chemical transport models
Scientic studies based on stratospheric data
Data Assimilation studies using balloon data
Validation of satellite data assimilation using dropsonde data
Fig. 2.1-10. The
Concordiasi project
timeline.
(Rabier et al., 2010)
s C I e n C e P r o g r a m 149