The influence of a sub-stellar continent on the climate of a tidally-locked exoplanet
American Astronomical Society
© 2018. The American Astronomical Society. All rights reserved.
Previous studies have demonstrated that continental carbon-silicate weathering is important to the continued habitability of a terrestrial planet. Despite this, few studies have considered the influence of land on the climate of a tidally-locked planet. In this work we use the Met Office Unified Model, coupled to a land surface model, to investigate the climate effects of a continent located at the sub-stellar point. We choose to use the orbital and planetary parameters of Proxima Centauri B as a template, to allow comparison with the work of others. A region of the surface where Ts > 273:15K is always retained, and previous conclusions on the habitability of Proxima Centauri B remain intact. We find that sub-stellar land causes global cooling, and increases day-night temperature contrasts by limiting heat redistribution. Furthermore, we find that sub-stellar land is able to introduce a regime change in the atmospheric circulation. Specifically, when a continent offset to the east of the sub-stellar point is introduced, we observe the formation of two mid-latitude counterrotating jets, and a substantially weakened equatorial superrotating jet.
N.T.L. and F.H.L are grateful to the London Mathematical Society for financial support by means of an undergraduate research bursary. I.A.B. and J.M. acknowledge the support of a Met Office Academic Partnership secondment. N.J.M.'s contributions were supported by a Leverhulme Trust Research Project Grant.
This is the author accepted manuscript. The final version is available from American Astronomical Society via the DOI in this record.
Vol. 854 (2). Published online 26 February 2018.