OCCUR—Study of the Chemistry−Climate Coupling in the UTLS Region with Satellite Measurements

Abstract

AbstractThis study, performed in the frame of the Changing Earth Science Network initiative, aims at investigating in particular the Upper Troposphere-Lower Stratosphere (UTLS) region with measurements acquired from satellite instruments and the aid of a chemical transport model. It is related to the “Challenge 4 of the Atmosphere” of the ESA Living Planet Program. The Challenge 4 addresses the following topic: Observe, monitor and understand the chemistry-dynamics coupling of the stratospheric and upper tropospheric circulations, and the apparent changes in these circulations. To contribute to this scientific challenge this study investigated the stratosphere and the UTLS region through the analysis of satellite observations using a tomographic approach, capable to take into account inhomogeneities of the atmosphere’s constituents. In this context, evidence of non-physical day-night differences in 1D retrievals has been found in a previous study performed on MIPAS spectra. These differences almost disappear using a tomographic approach, confirming that a 2D retrieval describes a more realistic picture of the atmosphere. These evidences have been confirmed with a 2D retrieval algorithm that has been expressly set up to analyse SCIAMACHY observations. The results of the study have also provided a new scientific understanding and support the definition of requirements for future Earth Explorers missions (i.e. an advanced imaging MIPAS spectrometer such as PREMIER).KeywordsTroposphereStratosphereOzoneChemical transport model