Mesospheric N<sub>2</sub>O enhancements as observed by MIPAS on Envisat during the polar winters in 2002?2004 - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Atmospheric Chemistry and Physics Discussions Année : 2008

Mesospheric N2O enhancements as observed by MIPAS on Envisat during the polar winters in 2002?2004

Résumé

N2O abundances ranging from 0.5 to 6 ppbv were observed in the polar upper stratosphere/lower mesosphere by the MIPAS instrument on the Envisat satellite during the Arctic and Antarctic winters in the period July 2002 to March 2004. A detailed study of the observed N2O?CH4 correlations shows that such enhancements are of chemical rather than dynamical origin. The N2O enhancements observed at 58 km occurred in presence of NOx intrusions from the upper atmosphere which were related to energetic particle precipitation. Further, the inter-annual variability of mesospheric N2O correlates well with observed precipitating electron fluxes. The analysis of possible chemical production mechanisms shows that the major part of the observed N2O enhancements is most likely generated under dark conditions by the reaction of NO2 with atomic nitrogen at altitudes around 70?75 km in the presence of energetic particle precipitation. A possible additional source of N2O in the middle and upper polar atmosphere is the reaction of N2(A3?u+), generated by precipitating electrons, with O2, which would lead to N2O production peaking at altitudes around 90?100 km. N2O produced by the latter mechanism could then descend to the mesosphere and upper stratosphere during polar winter.
Fichier principal
Vignette du fichier
acpd-8-10561-2008.pdf (2.34 Mo) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...

Dates et versions

hal-00304226 , version 1 (18-06-2008)

Identifiants

  • HAL Id : hal-00304226 , version 1

Citer

B. Funke, M. López-Puertas, M. García-Comas, G. P. Stiller, T. von Clarmann, et al.. Mesospheric N2O enhancements as observed by MIPAS on Envisat during the polar winters in 2002?2004. Atmospheric Chemistry and Physics Discussions, 2008, 8 (3), pp.10561-10596. ⟨hal-00304226⟩

Collections

INSU EGU
87 Consultations
67 Téléchargements

Partager

Gmail Facebook X LinkedIn More