Abstract: White community papers, Ocean'Obs09, Venice, September 21-25, 2009

Abstract: While the sample of confirmed exoplanets continues to grow, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (~1277 F?) and bloated Saturn-mass planet (1.69?0.06+0.05 RJup and 0.43?0.08+0.09 MJup) in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82?0.03+0.03 RJup and a mass of 0.30?0.08+0.07 MJup in a 6.40 day orbit. Despite its high insolation flux (~600 F?), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.39?0.04+0.02 MJup planet in a 4.88 day orbit with a grazing transit (b = 1.04?0.06+0.05) that results in a poorly constrained radius of 1.61?0.64+0.46 RJup. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and JWST. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation, and migration of exoplanets across various stellar types.

Abstract: While most precipitation in Antarctica falls as snow, little is known about liquid precipitation, although it can have ecological and climatic impacts. This study combines meteorological reports at 10 stations with the ERA5 reanalysis to provide a climatological characterization of rainfall occurrence over Antarctica. Along the East Antarctic coast, liquid precipitation occurs 22 days per year at most and coincides with maritime intrusions and blocking anticyclones. Over the north-western Antarctic Peninsula, rainfall occurs more than 50 days per year on average and the recent summer cooling was accompanied by a decrease of ?35 annual rainy days per decade between 1998 and 2015 at Faraday-Vernadsky. Projections from seven latest-generation climate models reveal that Antarctic coasts will experience a warming and more frequent and intense rainfall by the end of the century. Rainfall is expected to impact new regions of the continent, increasing their vulnerability to melting by the preconditioning of surface snow.