I am very pleased to hear that our paper is being very heavily cited by the scientific community. AIRS/AMSU/HSB represents a new state of the art infra-red and microwave atmospheric sounding system, flying on the EOS Aqua platform, designed to produce highly accurate global atmospheric soundings of temperature and moisture profiles in up to 80% partial cloud cover. These accurate soundings will be used both to improve operational forecast skill, as well as to study interannual variability and trends of atmospheric and surface geophysical parameters, an important factor in understanding global warming and the greenhouse effect.

This paper describes new methodology developed to determine these atmospheric and surface parameters from AIRS/AMSU/HSB data in the presence of clouds. The methodology is in fact very general and can be applied to a wide variety of remote sensing problems. The paper was written before the launch of EOS Aqua in May 2002. Therefore, all results shown are based on global simulated data. Results with real data are very similar to those obtained in simulation, and will be described shortly in a new paper. The paper may often be cited because of the new methodology developed, which is also the methodology being used in the production of the AIRS data products which are being distributed to the world. In addition, the paper has the important finding that the accuracy of retrieved geophysical parameters should degrade only very slowly with increasing cloudiness (this result is borne out by our experience with real data). Finally, this paper may be cited in a more generic way when other papers are discussing the new AIRS/AMSU/HSB sounding system.