Evidence for N2O v3 4.5 μm non-local thermodynamic equilibrium emission in the atmosphere

DOI: 
10.1029/2006GL028539
Publication date: 
31/01/2007
Main author: 
López-Puertas M.
IAA authors: 
López-Puertas M.;Funke B.;Bermejo-Pantaleón D.
Authors: 
López-Puertas M., Funke B., Bermejo-Pantaleón D., von Clarmann T., Stiller G.P., Grabowski U., Höpfner M.
Journal: 
Geophysical Research Letters
Publication type: 
Article
Volume: 
34
Pages: 
Number: 
L02825
Abstract: 
We present a clear evidence for N2O 4.5 μm non-local thermodynamic equilibrium (non-LTE) emissions in the daylight stratosphere and mesosphere from measurements by the MIPAS experiment on board Envisat. We have used non-LTE radiative transfer models in order to quantify the magnitude and extent of the non-LTE deviation of N2O(001) in the Earth's atmosphere. The departure from LTE in N2O during daytime commences at altitudes around 40-50 km, but have significant effects (10%) on daytime limb radiance down to tangent heights of 20 km. The enhancement increases rapidly with altitude, being 20-80% at 50 km, and reaching factors of 2-8 in the lower mesosphere. This study shows that the enhancement is mainly produced by absorption of solar radiation by N2O at 4.5 μm and by V-V collisions with N2(1). Non-LTE effects are also significant at nighttime, where LTE calculations overpredict N2O radiances by 10-20% at 40-55 km tangent heights. Copyright 2007 by the American Geophysical Union.
Database: 
WOK
SCOPUS
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2007GeoRL..34.2825L/abstract
ADS Bibcode: 
2007GeoRL..34.2825L
Keywords: