ClO infrared emission spectrum retrieval using the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)

• Main Author: Jim Robinson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2000
• Subjects: Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.506.7383; http://www-atm.physics.ox.ac.uk/group/mipas/reports/robinson.pdf

Infrared emission spectra for atmospheric profiles consisting of 17 gases, including chlorine monox-ide (ClO) corresponding to maximum observed lev-els (Antarctic winter), were simulated using the Ref-erence Forward Model (RFM) developed at the Uni-versity of Oxford for the forthcoming European Space Agency (ESA) Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) mission. Jacobians (Weighting Functions) were calculated using small per-turbations to the ClO profile to determine how accu-rately information about the ClO Volume Mixing Ra-tio (VMR) may be retrieved from MIPAS, corrections having been made for Field-Of-View (FOV) effects as well as noise apodisation. It was found that ClO pro-file information for Antarctic winter conditions may be retrieved within typical 1 error bars of 50 % (corre-sponding to 1.0 ppbv) at best, at altitudes of 17 km and 20 km. At 23km, the 1 bars were 80%, although it may be possible to achieve improved accuracy by av-eraging a number of single spectra. Outside the 17–23 km range, simulated error bars became too large for any useful measurements to be made. Furthermore, ClO is not sufficiently abundant at midlatitudes for useful pro-file information to be obtained. 1