Atmospheric Infrared Sounder Observations of Stratospheric Gravity Waves
Lars Hoffmann （Team leader 'Simulation Laboratory Climate Science' at Juelich Supercomputing Centre）
RM 1516 Teaching and research building (east campus)
Radiance measurements and temperature retrievals from the Atmospheric Infrared Sounder (AIRS) are well suited to study stratospheric gravity waves with short horizontal and long vertical wavelengths. In the talk we present the results of two papers. The first one deals with a new scheme to retrieve stratospheric temperatures from AIRS radiance measurements. The new retrieval scheme provides significantly better horizontal resolution (by a factor of 3 x 3) than the NASA operational Level-2 data and is hence much better suited to study small- or meso-scale gravity waves. Retrieval errors and characteristics of the new temperature data set will be presented. The second paper discusses the occurrence frequencies of deep convection and gravity waves during the North American thunderstorm season during the years 2003 to 2008. For this paper we developed, optimized and characterized new algorithms to detect deep convection and gravity waves directly from AIRS radiance measurements. A correlation analysis allows to determine the fraction of convective waves and the fraction of wave-emitting deep convection events. The statistics presented here will likely become a valuable data set for the validation of gravity wave parametrization schemes in climate models.