| The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)
observes atmospheric emissions in the mid-infrared (14.6 to 4.15 um)
with high spectral resolution (0.025 to 0.0625 cm-1). It was launched
into a polar sun-synchronous orbit on 1 March 2002 and has been
measuring, since then, 1000 to 1500 vertical scans through the
atmosphere every day, from pole to pole during day and night. The
measurements cover the altitude range from about 6 to 70 km in nominal
observation mode, and up to 170 km in special observation modes. In this
talk we will focus on the measurements taken by MIPAS in its upper
atmospheric mode (40-170 km).
As the NO emission lines are affected not only by vibrational non local
thermodynamic equilibrium (non-LTE), but also by rotational and spin
non-LTE processes, a non-LTE scheme including the three non-LTE
populations has been developed. This has been coupled with an inversion
scheme that allows to retrieve jointly the NO density and the kinetic
temperature from the rotationally resolved NO MIPAS spectra at 5.3 um.
In this talk, the methodology used and first results of retrieved kinetic
temperatures and nitric oxide densities in the thermosphere (110-160 km)
will be shown. |