Can thermal infrared nadir sounding provide information on air composition in the boundary layer?
This question can be answered by help of an Observing System Simulation
Experiment (OSSE). With this kind of experiments it is tested how much
feeding observational data in an assimilation system improves the quality
of the assimilated fields. In this figure, red colours indicate that the
ozone content in the lowermost troposphere is better represented when ozone
measurements by a thermal infrared nadir sounder are used. This OSSE was performed by Météo-France Toulouse using infrared
radiance spectra calculated with IMK's KOPRA radiative transfer model, which is also used
for the analysis of MIPAS data.
In this OSSE, the performance of the assimilation experiment with respect to a control run without use of the measurements under assessments is assessed in terms of the correlation between the resulting field and the reference field (the so-called nature run), the bias reduction and the reduction of the root mean squares differences. Different experimental setups are assessed.
The related article has recently been published in AMT:http://www.atmos-meas-tech.net/4/1637/2011/amt-4-1637-2011.html