Joanna Barstow

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Joanna Barstow

PDRA

I am currently a post-doctoral researcher in Planetary Physics. I completed a DPhil in Planetary Physics at Lady Margaret Hall, Oxford in 2011, with work on remote sensing of the clouds on Venus. I now work on simulating visible and infrared spectra of both extrasolar and solar system planets. I am a member of the Oxford Physics Outreach and Access committee, and a member of the Royal Astronomical Society Council (May 2015 -). I am also known as Joanna Eberhardt.

In 2011 I completed a DPhil thesis using infrared spectra from the VIRTIS instrument on Venus Express to study the Venusian lower cloud deck, which is made of concentrated sulphuric acid droplets. Venus is a planet under permanent cloud cover, and a good understanding of the cloud properties is essential for the correct interpretation of remote sensing data. I used a range of synthetic spectra to develop a quick method for determining cloud properties, and was able to map the variation in acid concentration across the night side southern hemisphere of the planet.

I am now applying similar tools to the study of extrasolar planet atmospheres. When extrasolar planets cross ('transit') in front of their parent stars, the observed reduction in starlight at different wavelengths can be used to determine properties of their atmospheres. I use radiative transfer simulations to calculate the visible and infrared spectra we would expect to observe for a range of planet sizes, temperatures and atmospheric compositions; I then investigate the feasibility of detecting atmospheric phenomena in these planets with space telescopes currently proposed or under development. Currently, I am using these techniques to inform future observations using the James Webb Space Telescope, and am a payload consortium member for the ESA M4 candidate mission Ariel.

I am still active in solar system research, with my current research focus being cloud structure on Saturn.

I am an active participant in public and schools outreach in the department, and coordinated the Stargazing Oxford outreach programme in the department between March 2013 and September 2014. I have given several lectures about my research to visiting schools groups, and recently took part in the London 2015 SoapBox Science event. I have also developed a classroom exercise based on inferring properties of extrasolar planets from lightcurves for school years 8-9.