Validation of the Improved Limb Atmospheric Spectrometer-II (ILAS-II) Version 1.4 nitrous oxide and methane profiles
Journal article, 2006
This study assesses polar stratospheric nitrous oxide (N(2)O) and methane (CH(4)) data from the Improved Limb Atmospheric Spectrometer-II (ILAS-II) on board the Advanced Earth Observing Satellite-II (ADEOS-II) retrieved by the Version 1.4 retrieval algorithm. The data were measured between January and October 2003. Vertical profiles of ILAS-II volume mixing ratio (VMR) data are compared with data from two balloon-borne instruments, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B) and the MkIV instrument, as well as with two satellite sensors, the Odin Sub-Millimetre Radiometer (SMR) for N(2)O and the Halogen Occultation Experiment (HALOE) for CH(4). Relative percentage differences between the ILAS-II and balloon/satellite data and their median values are calculated in 10-ppbv-wide bins for N(2)O (from 0 to 400 ppbv) and in 0.05-ppmv-wide bins for CH(4) (from 0 to 2 ppmv) in order to assess systematic differences between the ILAS-II and balloon/satellite data. According to this study, the characteristics of the ILAS-II Version 1.4 N(2)O and CH(4) data differ between hemispheres. For ILAS-II N(2)O VMR larger than 250 ppbv, the ILAS-II N(2)O agrees with the balloon/SMR N(2)O within +/- 20% in both hemispheres. The ILAS-II N(2)O in the VMR range from 30-50 to 250 ppbv (corresponding to altitudes of similar to 17-30 km in the Northern Hemisphere (NH, mainly outside the polar vortex) and similar to 13-21 km in the Southern Hemisphere (SH, mainly inside the polar vortex) is smaller by similar to 10-30% than the balloon/SMR N(2)O. For ILAS-II N(2)O VMR smaller than 30 ppbv (>similar to 21 km) in the SH, the differences between the ILAS-II and SMR N(2)O are within +/- 10 ppbv. For ILAS-II CH(4) VMR larger than 1 ppmv (
similar to 30 km) and the ILAS-II CH(4) for its VMR smaller than 1 ppmv (>similar to 25 km) only in the NH, are abnormally small compared to the balloon/satellite data.
ADEOS
SMR
ILAS
Odin
Author
M.K. Ejiri
National Institute for Environmental Studies of Japan
Utah State University
Y. Terao
Harvard University
T. Sugita
National Institute for Environmental Studies of Japan
H. Nakajima
National Institute for Environmental Studies of Japan
T. Yokota
National Institute for Environmental Studies of Japan
G. Toon
Jet Propulsion Laboratory, California Institute of Technology
B. Sen
Karlsruhe Institute of Technology (KIT)
G. Wetzel
Karlsruhe Institute of Technology (KIT)
H. Oelhaf
Karlsruhe Institute of Technology (KIT)
Joachim Urban
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
Donal Murtagh
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
H. Irie
Frontier Research Center for Global Change
N. Saitoh
National Institute for Environmental Studies of Japan
University of Tokyo
T. Tanaka
National Institute for Environmental Studies of Japan
H. Kanzawa
Nagoya University
M. Shiotani
Kyoto University
S. Aoki
Tohoku University
G. Hashida
National Institute of Polar Research
T. Machida
National Institute for Environmental Studies of Japan
T. Nakazawa
Tohoku University
H. Kobayashi
Central Research Institute of Electric Power Industry (CRIEPI)
Y. Sasano
National Institute for Environmental Studies of Japan
Journal of Geophysical Research
01480227 (ISSN) 21562202 (eISSN)
Vol. 111 D22 D22S90Subject Categories
Meteorology and Atmospheric Sciences
DOI
10.1029/2005JD006449