Shorter contribution Using cloudy AIRS fields of view in numerical weather prediction

The Atmospheric Infrared Sounder (AIRS) (Aumann et al. 2003; Chahine et al. 2006) was launched in 2002 on AQUA, the second of the EOS polar-orbiting satellites. The AIRS was the first of a new generation of meteorological advanced sounders able to provide hyperspectral data for operational and research use. Initially, we briefly review the first assimilation trials to use full spatial resolution and higher spectral resolution hyperspectral radiance data, available in real time from the AIRS. The result from these assimilation trials was significant improvement in forecast skill in the National Centers for Environmental Prediction (NCEP) Global Data Assimilation System (GDAS), compared to the global system without AIRS data over both the northern and southern hemispheres. A second trial was an experiment which showed the advantage of using all AIRS fields of view (fov) in the analysis as opposed to the use of sampled fields of view (typically one-in-eighteen) often used by numerical weather prediction (NWP) centres. Another trial showed the benefit of using hyperspectral data with expanded spectral coverage. We then describe recent experiments where radiances, derived from cloudy AIRS fovs and which represent the radiance emanating from the clear part of the cloudy fov, have been assimilated for global NWP. The beneficial impact of these data in the GDAS is recorded. The impact is an initial indication of the potential benefit of using cloudy hyperspectral radiances routinely in global NWP. Background