Wednesday 07 Oct 2015: Seminar: Gloomy planets: overcoming remote sensing challenges for cloudy atmospheres
Dr Jo Barstow - University of Oxford
Physics, 4th floor 13:30-14:30
For most planets, both inside and outside the solar system, our only knowledge about their atmospheres comes from remote sensing and spectroscopic analysis. There are often multiple, degenerate atmospheric states that could produce the observed spectra, and usually more complex atmospheric models result in greater numbers of permitted atmospheric states. The inclusion of clouds in an atmospheric model increases its complexity, due to the size of the cloud parameter space – the nature of the condensate, size of condensate particles, number density and location within the atmosphere all influence spectral features. Recent analyses of the best-studied extrasolar planets indicate that clouds are as ubiquitous outside the solar system as they are inside it, and their probable presence on these planets can no longer be ignored. I explore the significance of different cloud properties for reflection, emission and transmission spectra of planetary atmospheres, including examples such as the hints of enstatite clouds on HD 189733b, and the possibility of Titan-like hydrocarbon hazes on GJ 1214b. I will present suggestions for a framework to explore cloudy solutions for data-poor planets.