Stratomesospheric CO measured by a ground-based Fourier Transform Spectrometer over Poker Flat, Alaska: Comparisons with Odin/SMR and a 2-D model
Journal article, 2007
The interseasonal variability of stratomesospheric CO is reported from Poker Flat, Alaska, using spectra from a ground-based Fourier Transform Spectrometer (gb-FTS) for the time period from 2000 to 2004. The CO spectra were analyzed using an optimal estimation technique that separates the tropospheric and stratospheric/mesospheric components into partial columns. The distribution of CO in the polar winter is such that the gb-FTS retrieved partial column is weighted to the mesosphere. The gb-FTS data are compared with measurements of partial column CO from the Sub-Millimeter Radiometer on board the Odin satellite and shown to be in very good agreement despite the relatively small sample size. The mean difference of the two data sets indicates a small positive bias (7.6 +/- 6%) in favor of the Odin data, with a correlation coefficient, r(2) = 0.91. The gb-FTS data indicate that there is a strong seasonal dependence of the CO partial column that is consistent with known winter polar thermospheric descent of CO enriched air. Year-to-year variability is explained in terms of mesospheric wind dynamics, which show 2004 and components of 2002 were affected by earlier than expected breakdown (30 +/- 13 d) of the winter polar circulation compared with 2000 to 2003. Finally, the measured CO data is compared with a 2-D chemical transport model that gives support to the idea that springtime polar mesospheric CO is driven by meridional winds.
Fourier Transform Infrared Spectroscopy
Carbon monoxide
Mesosphere
Odin Sub-Millimetre Radiometer
Atmospheric circulation
Stratosphere
Author
N. Jones
University of Wollongong
Y. Kasai
Japan National Institute of Information and Communications Technology
E. Dupuy
University of Saskatchewan
Observatoire Aquitain des Sciences de l'Univers, OASU
Y. Murayama
Japan National Institute of Information and Communications Technology
National Institute of Polar Research
Joachim Urban
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
B. Barret
Paul Sabatier University
M. Sinnhuber
Universität Bremen
A. Kagawa
Japan National Institute of Information and Communications Technology
Fujitsu FTP Corporation
T. Koshiro
Kyoto University
P. Ricaud
Paul Sabatier University
Donal Murtagh
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
Journal of Geophysical Research
01480227 (ISSN) 21562202 (eISSN)
Vol. 112 D20 D20303Subject Categories
Meteorology and Atmospheric Sciences
Earth and Related Environmental Sciences
DOI
10.1029/2006JD007916