A great deal of my work has centred on planetary atmospheres.


In graduate school I began working on a test case for the Versatile Software for the Transfer of Atmospheric Radiation (VSTAR) using high resolution data from Gemini.  This presented us with an opportunity to measure the deuterium-to-hydrogen ratio in the planet (a proxy for determining the materials it originated from) using methane bands in the infrared.  This is of particular interest for our ice giants because they are believed to have formed much closer to the Sun than they currently orbit, undergoing a dramatic migration event early on.  Applying a similar approach to Neptune, estimates of the abundances for two different latitudes for each of these ice giants were determined to more precision (and with a more comprehensive cloud model) than in previous attempts.  The characterisation of the origins of ice giants is also of interest because of the exotic worlds called super Earths which we find in other solar systems.  We want to know under which circumstances an ice giant, versus a terrestrial super Earth, will form.

Hot Jupiters

Hot Jupiters are lovely to study, because they're relatively easy to study.  They're also exciting, because they're so incredibly "alien" to us Solar System dwellers.

Along with polarimetric observations of hot Jupiters, I used HST (Hubble) and Spitzer data along with VSTAR to characterise the atmospheres of hot Jupiters.  For HD 189733b, these models were used to produce an approximation of cloud structures used in a forward model for polarised light.  This forward model and limitations from literature in theory helped to validate our polarimetric observations with HiPPI.

Super Earths and Terrestrials

Finding ways to distinguish between different types of terrestrials (Venus, early Earth, Earth like, "dead", something-we-haven't-thought-of), and between true super-terrestrials and stripped ice giants will be vital to the habitability studies of the next few decades.  Most of my work focuses on using polarimetry as a tool to distinguish between these worlds from differences in their atmospheres, clouds and surfaces.  This assesses habitability.  Polarimetry holds the ability to identify some biosignatures, detect oceans, characterise clouds and characterise the bulk atmospheric composition.  Because of its inherent directional information it could also provide a means to map worlds and their weather, and provide orbital information.  Importantly, it is well suited to measure the reflected visible light of Earth-like temperate worlds around sun-like stars with its natural star-nulling and sensitivity (for Rayleigh scattering) in visible wavelengths.