High spatial resolution mapping of Mars mesospheric zonal winds by infrared heterodyne spectroscopy of CO2

We present Mars zonal wind measurements by means of infrared heterodyne spectroscopy of CO2 features at 959.3917 cm−1 (10.423 μm). Observations were carried out using the Cologne Tuneable Heterodyne Infrared Spectrometer (THIS) from 5–8 December 2005 shortly after Mars opposition at the McMath‐Pierce Solar Telescope of the National Solar Observatory on Kitt Peak in Arizona with an unprecedented spatial resolution of ∼1.7 arcsec on a ∼16 arcsec Martian disk. Mars was observed at six different latitudes close to the west (evening) limb and zonal winds were retrieved from Doppler shifts between CO2 non‐thermal emission from the mesosphere and absorption features from low atmospheric regions. The season on Mars was late northern winter (LS ≈ 337°). We retrieved retrograde winds at latitude 45°N (−27 ± 17 m/s) that were particularly strong at the equator (up to −80 ± 13 m/s) and prograde winds at high southern latitudes (75°S) up to 51 ± 29 m/s.