Some Comparisons of VAS and Dropwindsonde Data over the Subtropical Atlantic

Abstract

Abstract Omega dropwindsonde and other in situ (INS) data collected during the NOAA/Hurricane Research Division's (HRD) Hurricane Field Program are used as a ground truth dataset for the evaluation of VISSR Atmospheric Sounder (VAS) soundings over the subtropical Atlantic. The experiments were coordinated with the Cooperative Institute for Meteorological Satellite Services at the University of Wisconsin. The focus of this study is to determine whether soundings derived from VAS radiances are an improvement over the first-guess data used as a starting point in the sounding retrieval process. First guess inputs for this study are provided by NMCs Regional Analysis and Forecast System (RAFS) nested grid model (NGM). In a case study, an objective algorithm is used to analyze the INS, VAS, and first-guess data at and below 500 mb from an HRD experiment on 1–2 September 1988. The case study is supplemented by a statistical investigation of data composited from other HRD experiments. In particular, we examine VA...