TY - GEN
AU - Alan Geer
AU - Peter Bauer
AU - S.J. English
AB - A better assimilation of satellite radiances in cloudy and precipitating areas should help improve forecasts by (i) providing greater coverage of temperature and humidity in meteorologically active areas and (ii) directly constraining cloud and precipitation. Advanced Microwave Sounding Unit A (AMSU-A) is used for sensing atmospheric temperature and is one of the most important sensors in the global observing system, yet at ECMWF, except for a simple cloud-screening, it is still assimilated without considering the effect of cloud or precipitation. There may be benefits in using the ‘all-sky' approach, which is already operational for microwave imagers. To extend this to AMSU-A requires a model for observation error that prescribes larger errors in cloudy and precipitating regions than in clear skies, and larger errors at nadir where the weighting function sees deepest into the atmosphere.
BT - ECMWF Technical Memoranda
DA - 04/2012
DO - 10.21957/mbjps5x4j
LA - eng
M1 - 670
N1 - Also published as ECMWF/EUMETSAT Fellowship Programme Research Report No.24
N2 - A better assimilation of satellite radiances in cloudy and precipitating areas should help improve forecasts by (i) providing greater coverage of temperature and humidity in meteorologically active areas and (ii) directly constraining cloud and precipitation. Advanced Microwave Sounding Unit A (AMSU-A) is used for sensing atmospheric temperature and is one of the most important sensors in the global observing system, yet at ECMWF, except for a simple cloud-screening, it is still assimilated without considering the effect of cloud or precipitation. There may be benefits in using the ‘all-sky' approach, which is already operational for microwave imagers. To extend this to AMSU-A requires a model for observation error that prescribes larger errors in cloudy and precipitating regions than in clear skies, and larger errors at nadir where the weighting function sees deepest into the atmosphere.
PB - ECMWF
PY - 2012
EP - 41
T2 - ECMWF Technical Memoranda
TI - Assimilating AMSU-A temperature sounding channels in the presence of cloud and precipitation
UR - https://www.ecmwf.int/node/9514
ER -