Probing Atmospheric Properties of Mars and Venus by High-Resolution Infrared Heterodyne Spectroscopy of CO2

• Applicant: Dr. Guido Sonnabend
• Subject Area: Atmospheric Science
• Term: from 2006 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 33669283

Understanding of the physical and chemical processes in planetary atmospheres is essential for the development of general circulation models (GCM) and meteorological forecast models. This is not only true for Earth but for the other terrestrial planets, Mars and Venus, as well. Especially in the case of Mars, atmospheric models have been improved substantially over the last few years due to constraints imposed by the data that became available from several space missions e.g. MarsExpress or Mars Global Surveyor (MGS) and the Mars Rovers. Nevertheless these data are only selective and mainly from the surface and from limited altitude regions of Mars. Observations in other (higher) atmospheric regions are rare but are necessary to constrain the models and to prepare for future space missions and landers to the Red Planet. One forecast parameter is zonal wind velocity. Similar to jet streams on Earth global zonal flows are predicted for Mars with wind velocities up to 200 m/s near 80 km altitude. An elegant method to measure high atmospheric winds is by observing infrared CO2 absorption and emission lines with high spectral resolution heterodyne spectroscopy. From line frequency (Doppler-)shifts velocities of the emitting and absorbing gas can be directly deduced. In contrast to microwave observations an adequate spatial resolution can be achieved in addition to the high spectral resolution with the infrared heterodyne observing technique. Similar observations are planned on Venus in the support of the ESA VenusExpress space mission.

• DFG Programme: Research Grants
• International Connection: Austria, France, Spain, United Kingdom, USA
• Participating Persons: Dr. Theodor Kostiuk; Dr. Stephen R. Lewis; Dr. Miguel A. Lopez-Valverde; Professor Dr. Helmut Rucker; Dr. Thomas Widemann