Measurements of mid-stratospheric formaldehyde from the Odin/SMR instrument

P. Ricaud; D. Alexandre; B. Barret; E. Le Flochmoen; E. Motte; G. Berthet; F. Lefévre; Donal Murtagh

doi:10.1016/j.jqsrt.2007.01.058

Measurements of mid-stratospheric formaldehyde from the Odin/SMR instrument
Journal article, 2007

Measurements of mid-stratospheric formaldehyde (H2CO) have been obtained from the limb-viewing sub-millimeter radiometer (SMR) instrument aboard the Odin satellite. The analysis is based upon the only weak (808 -> 707) rotational transition line Of H2CO that can be measured by Odin/SMR at 576.7083150GHz in the band dedicated to the measurement of carbon monoxide (CO). The signal-to-noise ratio is increased by averaging about 1000 spectra within 2-km width vertical layers in the stratosphere over periods from I to 7 days and within 3 latitude bands: Southern Hemisphere (90 degrees S-45 degrees S), tropics (30 degrees S-30 degrees N), and Northern Hemisphere (45 degrees N-90 degrees N). The faint H2CO line can then be retrieved using the standard scientific ground-segment developed for the Odin/SMR measurements. The mid-stratospheric H2CO shows maxima in the tropics for every period considered (January 2006, February 2005, March 2005, and September 2005). The spring-time extra-tropical mid-strato spheric H2CO is more intense than the fall-time extra-tropical amounts. The simulations from the three-dimensional chemical- transport model Reprobus satisfactorily show these general features. (C) 2007 Elsevier Ltd. All rights reserved.

PERFORMANCE

sensing

stratosphere

spectroscopy

remote

HETERODYNE MEASUREMENTS

SUBMILLIMETER

CHLORINE MONOXIDE

OZONE

formaldehyde

inversion

CLO

SATELLITE

radiative transfer

MODEL

MILLIMETER

RADIOMETER

satellite