Assimilation of hyperspectral radiances in the NCMRWF global forecast system

Abstract

The availability of high resolution temperature and water vapor data is important for the study of mesoscale scale weather phenomena. As, Atmospheric Infrared Sounder (AIRS), Cross-Track Infrared Sounder (CrIS) and European Infrared Atmospheric Sounding Interferometer (IASI) provide high resolution atmospheric profiles by measuring radiations in many thousands of different channels. The AIRS, on the EOS-Aqua polar-orbiting satellite, was the first of a new generation of meteorological advanced sounders able to provide hyper- spectral data for operational and research use. The CrIS is a Fourier Transform Michelson interferometer instrument launched on board the Suomi National Polar- Orbiting Partnership (Suomi NPP) satellite on 28 October 2011. CrIS is a major step forward in the U.S. operational infrared (IR) sounding capability previously provided by the High-resolution Infrared Spectrometer (HIRS). The IASI is the most advanced instrument carried on the MetOp satellite on 19 October 2006. As a result, demonstration of the benefit of hyper-spectral data on Numerical Weather Prediction (NWP) has been a high priority. This work focuses on the assessment of the potential values of satellite hyper-spectral radiance data in the NGFS (National Centre for Medium Range Weather Forecasting-Global Forecast System). An Observing System Experiments (OSEs) has been conducted to examine the impact of hyper-spectral radiances and detail results are presented.