Stratospheric Impact of 1DVariation Assimilation of TOVS/ATOVS Data

This paper will present an assessment of the impact to the stratospheric circulation of the DAO-GEOS2 (Data Assimilation Office -Goddard Earth Observing System) attributable to an improved 1DVaritional retrieval of heights. The assimilated heights are retrieved from both the TOVS (TIROS Operational Vertical Sounder) and the ATOVS (Advanced TOVS) sounders. Each sounder's sensitivity to temperature changes in the stratosphere will be addressed and its relationship to the model's background flow evaluated. Also detailed are the steps to ensure the quality of the data being assimilated. Finally the temporal and spatial scales, important to the stratospheric mean flow, will be evaluated in terms of the DAO-GEOS2 response to the assimilated heights.