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
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.
URL:
https://ui.adsabs.harvard.edu/#abs/2007GeoRL..34.2825L/abstract