Evaluation of stratospheric radio occultation retrieval using data from CHAMP, MIPAS, GOMOS, and ECMWF analysis fields

Abstract

Two radio occultation (RO) retrieval schemes designed at IGAM to enhance the performance at high altitudes are presented, applied to CHAMP RO data, and validated against ECMWF analyses, GFZ operational retrieval, ENVSAT/MIPAS-, and ENVIAT/GOMOS-derived temperature profiles. IGAM proposes to include background information into the RO retrieval only at one point at bending angle level in order to be able to track error characteristics of the retrieved product. The results show very good agreement with GFZ retrieval and ECMWF analysis below 15 km and, depending on the background information used, either a significant warm bias or essentially no bias up to 30 km. Compared to MIPAS, the only independent data source, the IGAM/ECMWF retrieval is unbiased up to 40 km. © 2005 Springer-Verlag Berlin Heidelberg.