When: Thursday 2 December at 14.00
Where: Microsoft Teams - Online
Speaker: Jon Mason (OU)
Hosted by: Chiaki Crews
The Nadir and Occultation for Mars Discovery (NOMAD) spectrometer suite onboard the Trace Gas Orbiter (TGO) has been conducting science operations for nearly 3 years in orbit around Mars; providing global measurements of atmospheric Trace Gases and aerosols. The NOMAD instrument consists of three spectrometers: Two infra-red channels and one Ultraviolet and VISible (UVIS) channel. The UVIS channel was designed in house at the Open University and the ExoMars team is responsible for the day-to-day operation of the instrument, processing of the UVIS data, and the scientific analysis and interpretation. The primary science of UVIS is to map the spatial and temporal abundances of ozone, the ubiquitous Mars dust and ice aerosols as well as the vertical distribution of these species. Results from the NOMAD IR channels have place the upper limit on the methane abundance in the martian atmosphere to be 0.012-0.15 ppbv, this is significantly lower than those reported by MSL and Earth based observations. New UVIS results have detected the green (557.7 nm) line oxygen emission between 70-120 km in the martian atmosphere. This is the first detection of its kind around another terrestrial planet other than Earth. UVIS Solar occultation measurements have shown the presence of a high-altitude ozone layer around 40-50 km in the southern hemisphere and to a lesser extent at northern high latitudes. Significant equatorial ozone has also been observed from UVIS nadir observations during the Mars aphelion season, coinciding with a cooler and dryer atmosphere.
In this seminar I will give an overview of the TGO mission and the NOMAD instrument, going into more detail about the UVIS channel. I will describe the orbital characteristics and the observational modes employed by UVIS to measure different aspects of ozone and aerosol species. Finally, we will look at the science results from the NOMAD instrument.
Jon has worked at the Open University for over 10 years, first completing his PhD and then becoming a member of the ExoMars team responsible for the design, build, and testing of the UVIS instrument prior to its launch in 2016. His current role is operations lead for the UVIS instrument, where he is responsible for the day-to-day running of the instrument, observational planning and the processing and analysis of returned data.