Intercomparison of ILAS-II Version 1.4 and Version 2 target parameters with MIPAS-Envisat measurements

Content Provider	Scilit
Author	Griesfeller, A. von Clarmann, T. Griesfeller, J. Höpfner, M. Milz, M. Nakajima, H. Steck, T. Sugita, T. Tanaka, T. Yokota, T.
Copyright Year	2007
Description	This paper assesses the mean differences between the two ILAS-II data versions (1.4 and 2) by comparing them with MIPAS measurements made between May and October 2003. For comparison with ILAS-II results, MIPAS data processed at the Institut für Meteorologie und Klimaforschung, Karlsruhe, Germany (IMK) in cooperation with the Instituto de Astrofísica de Andalucía (IAA) in Granada, Spain, were used. The coincidence criteria of ±300 km in space and ±12 h in time for $H_{2}$O, $N_{2}$O, and $CH_{4}$ and the coincidence criteria of ±300 km in space and ±6 h in time for $ClONO_{2}$, $O_{3}$, and $HNO_{3}$ were used. The ILAS-II data were separated into sunrise (= Northern Hemisphere) and sunset (= Southern Hemisphere). For the sunrise data, a clear improvement from version 1.4 to version 2 was observed for $H_{2}$O, $CH_{4}$, $ClONO_{2}$, and $O_{3}$. In particular, the ILAS-II version 1.4 mixing ratios of $H_{2}$O and $CH_{4}$ were unrealistically small, and those of $ClONO_{2}$ above altitudes of 30 km unrealistically large. For $N_{2}$O and $HNO_{3}$, there were no large differences between the two versions. Contrary to the Northern Hemisphere, where some exceptional profiles deviated significantly from known climatology, no such outlying profiles were found in the Southern Hemisphere for both versions. Generally, the ILAS-II version 2 data were in better agreement with the MIPAS data than the version 1.4, and are recommended for quantitative analysis in the stratosphere. For $H_{2}$O data in the Southern Hemisphere, further data quality evaluation is necessary.
Ending Page	843
Page Count	19
Starting Page	825
DOI	10.5194/acpd-7-9319-2007
Alternate Webpage(s)	https://hal.archives-ouvertes.fr/hal-00296450/file/acp-8-825-2008.pdf
Issue Number	4
Volume Number	8
Language	English
Publisher	Copernicus GmbH
Publisher Date	2007-07-02
Access Restriction	Open
Subject Keyword	Atmospheric Sciences Ilas Ii Mipas Data Differences Between the Two Ii Version
Content Type	Text
Resource Type	Article