Mapping of temperature and line-of-sight errors in constituent retrievals for MIPAS/ENVISAT measurements

An optimized code for the near real-time retrieval of line of sight, temper ature and volume-mixing ratio profiles of five key species (O-3, H2O, HNO3, CH4 and N2O) from infrared limb spectra recorded by the Michelson Interfer ometer for Passive Atmospheric Sounding (MIPAS) experiment on board the ENV ISAT-1 satellite was developed as part of an ESA-supported study. In this c ode line of sight and temperature are retrieved simultaneously among themse lves, bur sequentially with respect to the volume-mixing ratio of the five key species. The sequential retrieval leaves unaccounted the mapping of lin e of sight and temperature errors in the retrieved volume-mixing ratio of t he constituents. This paper illustrates an algorithm that provides the a-po steriori evaluation of temperature and line-of-sight-induced error on the r etrieved volume-mixing ratio of the MIPAS key species. It is shown that in most cases temperature and line-of-sight-induced error provides a significa nt contribution to the total volume-mixing ratio error. The variability of this error as a function of latitude, season and atmospheric model is also analyzed. (C) 2000 Elsevier Science Ltd. All rights reserved.