TY  - JOUR
AU  - Nathalie Boullot, Florence Rabier
PY  - 2016//
TI  - Observation impact over the southern polar area during the Concordiasi field campaign
KW  - dropsondes forecast score forecast sensitivity to observations observing-system experiment
N2  - The impact of observations on analysis uncertainty and forecast performance was investigated for austral spring 2010 over the southern polar area for four different systems (NRL, GMAO, ECMWF and Météo-France) at the time of the Concordiasi field experiment. The largest multi-model variance in 500 hPa height analyses is found in the southern sub-Antarctic oceanic region, where there are rapidly evolving weather systems, rapid forecast-error growth, and fewer upper-air wind observation data to constrain the analyses. The total impact of all observations on the model forecast was computed using the 24 h forecast sensitivity-to-observations diagnostic. Observation types that contribute most to the reduction of the forecast error are shown to be AMSU, IASI, AIRS, GPS-RO, radiosonde, surface and atmospheric motion vector observations. For sounding data, radiosondes and dropsondes, one can note a large impact on the analysis and forecasts of temperature at low levels and a large impact of wind at high levels. Observing system experiments using the Concordiasi dropsondes show a large impact of the observations over the Antarctic plateau extending to lower latitudes with the forecast range, with the largest impact around 50–70°S. These experiments indicate there is a potential benefit from using radiance data better over land and sea-ice and from innovative atmospheric motion vectors obtained from a combination of various satellites to fill the current data gaps and improve numerical weather prediction analyses in this region.
SN  - 1477-870X
UR  - http://dx.doi.org/10.1002/qj.2470
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=8281), last updated on Wed, 03 Jul 2024 21:43:48 +0200
ID  - NathalieBoullot2016
ER  -