Light reflected by planetary atmospheres and/or surfaces is polarised, and the degree and direction of polarisation can yield information that cannot always be gleaned from flux measurements alone. Polarimetric studies of solar system planets can reveal more details about the seasonal variations in their atmospheres, and the variation with orbital geometry can place constraints on the properties of cloud particles. With the advent of extremely large telescopes, and potentially the most accurate instruments ever realised thus far, polarimetry has great potential for both detecting and characterising exoplanets. A key difference when observing exoplanets with respect to the planets of our solar system is that despite the much lower signal-to-noise than solar system planets, we can access them at wider phase angle ranges, thus enabling us to probe their scattering properties more extensively, especially at geometries where the degree of polarisation is highest. This can result in an easier interpretation of the atmospheric characteristics through theoretical modelling. My original contribution to the field that is presented in this thesis is the observation, data reduction and analysis of polarimetric data along with model interpretation of the six most outer solar system planets and Titan. In addition, model results for exoplanets of varying types are shown and discussed. The overall goal is to show that polarimetry is necessary for giving a full description of light reflected by planetary atmospheres and surfaces, and to demonstrate its worth as a diagnostic tool for atmospheric characterisation, from both ground-based observations of solar system and exoplanets, and from in-situ missions to the outer planets, such as a potential atmospheric probe into any of the outer planets.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:731451 |
| Date | January 2017 |
| Creators | McLean, William George King |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/98039/ |
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