Photochemistry on Mars: preparing for data from the ExoMars Trace Gas Orbiter

Project Description:

Detecting and understanding observed atmospheric variations of organic compounds on Mars represents the first step towards addressing the question "does Mars support biological activity?". Atmospheric chemistry measurements collected by the NOMAD and ACS instruments aboard the ExoMars Trace Gas Orbiter (TGO) will provide us with a more comprehensive view of Mars’ photochemical environment than available from previous instruments (e.g., SPICAM and MARCI). The TGO reached Mars in late 2016 and has now started its aerobraking phase to lower itself into its final science orbit around Mars.

The project has four key science questions:

1) How do physical, geological, biological and chemical processes perturb VOC-HOx-NOx-Ox atmospheric chemistry on Mars?
2) What are the bounds on atmospheric lifetimes of CH4 and non-methane VOCs on Mars?
3) Does a more comprehensive description of Mars photochemistry improve model agreement with SPICAM and MARCI observations?
4) Does the model reproduce variations of atmospheric trace gases observed by TGO instruments?

In collaboration with colleagues at the Open University the student will develop the chemical mechanism in an existing 1-D photochemical sub-model of the UK Mars General Circulation Model (MGCM) so it can be used to interpret observed atmospheric variations of methane (CH4) and non-methane volatile organic compounds (VOCs) within the broader context of VOC-HOx-NOx-Ox chemistry. The student will develop a more comprehensive chemical mechanism; understand how different emissions and chemical scenarios might be observed by the NOMAD and ACS instruments aboard the ExoMars TGO using synthetic experiments; and evaluate the 1-D model using TGO data as they become available. The revised 1-D sub-model will eventually be integrated back into the UK MGCM.

Application procedure:

Please submit an application via the university’s online system (http://www.ed.ac.uk/studying/postgraduate/degrees/index.php?r=site/view&id=95). Please submit a copy of your CV instead of a research proposal, two academic references and copies of your degree documents (certificates and transcripts). We will require translations of any documents not in English.