Browsing by Author "Wordsworth, Robin"
Now showing items 1-20 of 32
-
3D climate modeling of close-in land planets: Circulation patterns, climate moist bistability, and habitability
Leconte, J.; Forget, F.; Charnay, B.; Wordsworth, Robin; Selsis, F.; Millour, E.; Spiga, A. (EDP Sciences, 2013)The inner edge of the classical habitable zone is often defined by the critical flux needed to trigger the runaway greenhouse instability. This 1D notion of a critical flux, however, may not be all that relevant for ... -
3D modelling of the climatic impact of outflow channel formation events on early Mars
Turbet, Martin; Forget, Francois; Head, James W.; Wordsworth, Robin (Elsevier BV, 2017)Mars was characterized by cataclysmic groundwater-sourced surface flooding that formed large outflow channels and that may have altered the climate for extensive periods during the Hesperian era. In particular, it has been ... -
3D modelling of the early martian climate under a denser \(CO_2\) atmosphere: Temperatures and \(CO_2\) ice clouds
Forget, F.; Wordsworth, Robin; Millour, E.; Madeleine, J.-B.; Kerber, L.; Leconte, J.; Marcq, E.; Haberle, R.M. (Elsevier BV, 2013)On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global ... -
Abiotic oxygen-dominated atmospheres on terrestrial habitable zone planets
Wordsworth, Robin; Pierrehumbert, Raymond (IOP Publishing, 2014)Detection of life on other planets requires identification of biosignatures, i.e., observable planetary properties that robustly indicate the presence of a biosphere. One of the most widely accepted biosignatures for an ... -
Anisotropic turbulence and zonal jets in rotating flows with a β-effect
Galperin, B.; Sukoriansky, S.; Dikovskaya, N.; Read, P. L.; Yamazaki, Y. H.; Wordsworth, Robin (Copernicus GmbH, 2006)Numerical studies of small-scale forced, two-dimensional turbulent flows on the surface of a rotating sphere have revealed strong large-scale anisotropization that culminates in the emergence of quasi-steady sets of ... -
Atmospheric Circulation of Terrestrial Exoplanets
Showman, Adam P.; Wordsworth, Robin; Merlis, Timothy M.; Kaspi, YohaiThe investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, ... -
Atmospheric Constraints on the Surface UV Environment of Mars at 3.9 Ga Relevant to Prebiotic Chemistry
Ranjan, Sukrit; Wordsworth, Robin; Sasselov, Dimitar D. (Mary Ann Liebert Inc, 2017)Recent findings suggest Mars may have been a clement environment for the emergence of life, and may even have compared favorably to Earth in this regard. These findings have revived interest in the hypothesis that prebiotically ... -
Atmospheric Heat Redistribution and Collapse on Tidally Locked Rocky Planets
Wordsworth, Robin (IOP Publishing, 2015)Atmospheric collapse is likely to be of fundamental importance to tidally locked rocky exoplanets, but it remains understudied. Here, general results on the heat transport and stability of tidally locked terrestrial-type ... -
Atmospheric nitrogen evolution on Earth and Venus
Wordsworth, Robin (Elsevier BV, 2016)Nitrogen is the most common element in Earth's atmosphere and also appears to be present in significant amounts in the mantle. However, its long-term cycling between these two reservoirs remains poorly understood. Here a ... -
The Climate of Early Mars
Wordsworth, Robin (Annual Reviews, 2016)The nature of the early martian climate is one of the major unanswered questions of planetary science. Key challenges remain, but a new wave of orbital and in situ observations and improvements in climate modeling have led ... -
Comparison of “warm and wet” and “cold and icy” scenarios for early Mars in a 3-D climate model
Wordsworth, Robin; Kerber, Laura; Pierrehumbert, Raymond T.; Forget, Francois; Head, James W. (Wiley-Blackwell, 2015)We use a 3-D general circulation model to compare the primitive Martian hydrological cycle in “warm and wet” and “cold and icy” scenarios. In the warm and wet scenario, an anomalously high solar flux or intense greenhouse ... -
Dynamics of Convectively Driven Banded Jets in the Laboratory
Read, Peter L.; Yamazaki, Yasuhiro H.; Lewis, Stephen R.; Williams, Paul D.; Wordsworth, Robin; Miki-Yamazaki, Kuniko; Sommeria, Joël; Didelle, Henri (American Meteorological Society, 2007)The banded organization of clouds and zonal winds in the atmospheres of the outer planets has long fascinated observers. Several recent studies in the theory and idealized modeling of geostrophic turbulence have suggested ... -
Earth’s Polar Night Boundary Layer as an Analog for Dark Side Inversions on Synchronously Rotating Terrestrial Exoplanets
Joshi, M. M.; Elvidge, A. D.; Wordsworth, Robin; Sergeev, D. (American Astronomical Society, 2020-04-03)A key factor in determining the potential habitability of synchronously rotating planets is the strength of the atmospheric boundary layer inversion between the dark side surface and the free atmosphere. Here we analyze ... -
Enabling Martian Habitability With Silica Aerogel via the Solid-State Greenhouse Effect
Wordsworth, Robin; Kerber, L; Cockell, C (Springer Science and Business Media LLC, 2019-07-15)The low temperatures and high ultraviolet radiation levels at the surface of Mars today currently preclude the survival of life anywhere except perhaps in limited subsurface niches4. Several ideas for making the Martian ... -
Exploring the faint young Sun problem and the possible climates of the Archean Earth with a 3-D GCM
Charnay, B.; Forget, F.; Wordsworth, Robin; Leconte, J.; Millour, E.; Codron, F.; Spiga, A. (Wiley-Blackwell, 2013)Different solutions have been proposed to solve the “faint young Sun problem,” defined by the fact that the Earth was not fully frozen during the Archean despite the fainter Sun. Most previous studies were performed with ... -
Gliese 581d is the first discovered terrestrial-mass exoplanet in the habitable zone
Wordsworth, Robin; Forget, François; Selsis, Franck; Millour, Ehouarn; Charnay, Benjamin; Madeleine, Jean-Baptiste (IOP Publishing, 2011)It has been suggested that the recently discovered exoplanet GJ581d might be able to support liquid water due to its relatively low mass and orbital distance. However, GJ581d receives 35% less stellar energy than Mars and ... -
Global modelling of the early martian climate under a denser \(CO_2\) atmosphere: Water cycle and ice evolution
Wordsworth, Robin; Forget, F.; Millour, E.; Head, J.W.; Madeleine, J.-B.; Charnay, B. (Elsevier BV, 2013)We discuss 3D global simulations of the early martian climate that we have performed assuming a faint young Sun and denser CO2 atmosphere. We include a self-consistent representation of the water cycle, with atmosphere–surface ... -
Hydrogen-Nitrogen Greenhouse Warming in Earth's Early Atmosphere
Wordsworth, Robin; Pierrehumbert, Raymond (American Association for the Advancement of Science (AAAS), 2013)Understanding how Earth has sustained surface liquid water throughout its history remains a key challenge, given that the Sun’s luminosity was much lower in the past. Here we show that with an atmospheric composition ... -
Initiation of Snowball Earth with volcanic sulfur aerosol emissions
Macdonald, Francis Alexander; Wordsworth, Robin (Wiley-Blackwell, 2017)We propose that the first Neoproterozoic Snowball Earth event, the Sturtian glaciation, was initiated by the injection of sulfate aerosols into the stratosphere. Geochronological data indicate that the Natkusiak magmatic ... -
Is Gliese 581d habitable? Some constraints from radiative-convective climate modeling
Wordsworth, Robin; Forget, F.; Selsis, F.; Madeleine, J.-B.; Millour, E.; Eymet, V. (EDP Sciences, 2010)The recently discovered exoplanet Gl 581d is extremely close to the outer edge of its system’s habitable zone, which has led to much speculation on its possible climate. We have performed a range of simulations to assess ...