MIPAS observation of ozone chemiluminescence at 5 um analyzed by a new non-lte model

MARTIN KAUFMANN; BEATRIZ M. TOSELLI; RAFAEL P. FERNANDEZ; S. GIL-LOPEZ; M. LÓPEZ-PUERTAS; B. FUNKE; G. STILLER; L. HOFFMANN; M. RIESE

Beijing

Congreso; Space Research 36th COSPAR Scientific Assembly; 2006

Comitee on Space Research (COSPAR)

The proper characterization of ozone mid-ir radiances under non-LTE conditions is very important for the retrieval of mesospheric constituents, such as ozone or carbon monoxide. A recent study of Kaufmann et al. [2006] indicated very large Envisat-MIPAS radiances at 4.8 um and suggested significant changes to standard non-LTE models of ozone to fit the measurements. To verify and extend these results, we developed a new ozone non-LTE model for the main vibrational-translational (VT) relaxation channels of ozone based on the theory of Schwartz-Slawsky-Herzfeld. The VT relaxation rates are compared with the standard approach using a Landau-Teller type scaling law. In addition to VT relaxation, we also consider vibrational-vibrational energy exchange with O2 for various transitions and demonstrate the importance of this relaxation path for many vibrational levels. Finally, the non-LTE model parameters are constrained by comparing simulated 5 um radiances with observations of the MIPAS instrument at stratospheric altitudes where the atmospheric state can be characterizedfrom MIPAS measurements not affected by non-LTE.