Open AccessOdin/SMR limb observations of stratospheric trace gases: Validation of N 2 O
Author(s) -
Urban J.,
Lautié N.,
Le Flochmoën E.,
Jiménez C.,
Eriksson P.,
de La Noë J.,
Dupuy E.,
El Amraoui L.,
Frisk U.,
Jégou F.,
Murtagh D.,
Olberg M.,
Ricaud P.,
CamyPeyret C.,
Dufour G.,
Payan S.,
Huret N.,
Pirre M.,
Robinson A. D.,
Harris N. R. P.,
Bremer H.,
Kleinböhl A.,
Küllmann K.,
Künzi K.,
Kuttippurath J.,
Ejiri M. K.,
Nakajima H.,
Sasano Y.,
Sugita T.,
Yokota T.,
Piccolo C.,
Raspollini P.,
Ridolfi M.
Publication year - 2005
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2004jd005394
Subject(s) - trace gas , radiometer , satellite , mixing ratio , environmental science , atmospheric sounding , root mean square , stratosphere , remote sensing , microwave radiometer , depth sounding , atmospheric sciences , meteorology , physics , geology , oceanography , quantum mechanics , astronomy
The Sub‐Millimetre Radiometer (Odin/SMR) on board the Odin satellite, launched on 20 February 2001, performs regular measurements of the global distribution of stratospheric nitrous oxide (N 2 O) using spectral observations of the J = 20 → 19 rotational transition centered at 502.296 GHz. We present a quality assessment for the retrieved N 2 O profiles (level 2 product) by comparison with independent balloonborne and aircraftborne validation measurements as well as by cross‐comparing with preliminary results from other satellite instruments. An agreement with the airborne validation experiments within 28 ppbv in terms of the root mean square (RMS) deviation is found for all SMR data versions (v222, v223, and v1.2) under investigation. More precisely, the agreement is within 19 ppbv for N 2 O volume mixing ratios (VMR) lower than 200 ppbv and within 10% for mixing ratios larger than 150 ppbv. Given the uncertainties due to atmospheric variability inherent to such comparisons, these values should be interpreted as upper limits for the systematic error of the Odin/SMR N 2 O measurements. Odin/SMR N 2 O mixing ratios are systematically slightly higher than nonvalidated data obtained from the Improved Limb Atmospheric Spectrometer‐II (ILAS‐II) on board the Advanced Earth Observing Satellite‐II (ADEOS‐II). Root mean square deviations are generally within 23 ppbv (or 20% for VMR‐N 2 O > 100 ppbv) for versions 222 and 223. The comparison with data obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the Envisat satellite yields a good agreement within 9–17 ppbv (or 10% for VMR‐N 2 O > 100 ppbv) for the same data versions. Odin/SMR version 1.2 data show somewhat larger RMS deviations and a higher positive bias.