Planetary Climate Dynamics

Research group

Research theme

Sub department

About

Indicate separate contributions of long-lived and short-lived greenhouse gases in emission targets

npj Climate and Atmospheric Science Springer Nature 5:1 (2022) 5

Authors:

Myles R Allen, Glen P Peters, Keith P Shine, Christian Azar, Paul Balcombe, Olivier Boucher, Michelle Cain, Philippe Ciais, William Collins, Piers M Forster, Dave J Frame, Pierre Friedlingstein, Claire Fyson, Thomas Gasser, Bill Hare, Stuart Jenkins, Steven P Hamburg, Daniel JA Johansson, John Lynch, Adrian Macey, Johannes Morfeldt, Alexander Nauels, Ilissa Ocko, Michael Oppenheimer, Stephen W Pacala, Raymond Pierrehumbert, Joeri Rogelj, Michiel Schaeffer, Carl F Schleussner, Drew Shindell, Ragnhild B Skeie, Stephen M Smith, Katsumasa Tanaka
More details from the publisher
Details from ORA
More details
More details

Blue marble, stagnant lid: Could dynamic topography avert a waterworld?

ArXiv 2201.05636 (2022)

Authors:

Claire Marie Guimond, John Rudge, Oliver Shorttle
Details from ArXiV

HST/WFC3 Complete Phase-resolved Spectroscopy of White-dwarf-brown-dwarf Binaries WD 0137 and EPIC 2122

ASTRONOMICAL JOURNAL 163:1 (2022) ARTN 17

Authors:

Yifan Zhou, Daniel Apai, Xianyu Tan, Joshua D Lothringer, Ben WP Lew, Sarah L Casewell, Vivien Parmentier, Mark S Marley, Siyi Xu, LC Mayorga
More details from the publisher
More details
More details

Blue marble, stagnant lid: Could dynamic topography avert a waterworld?

The Planetary Science Journal 3:3 (2022)

Authors:

Claire Marie Guimond, John Rudge, Oliver Shorttle

Abstract:

Topography on a wet rocky exoplanet could raise land above its sea level. Although land elevation is the product of many complex processes, the large-scale topographic features on any geodynamically-active planet are the expression of the convecting mantle beneath the surface. This so-called "dynamic topography" exists regardless of a planet's tectonic regime or volcanism; its amplitude, with a few assumptions, can be estimated via numerical simulations of convection as a function of the mantle Rayleigh number. We develop new scaling relationships for dynamic topography on stagnant lid planets using 2D convection models with temperature-dependent viscosity. These scalings are applied to 1D thermal history models to explore how dynamic topography varies with exoplanetary observables over a wide parameter space. Dynamic topography amplitudes are converted to an ocean basin capacity, the minimum water volume required to flood the entire surface. Basin capacity increases less steeply with planet mass than does the amount of water itself, assuming a water inventory that is a constant planetary mass fraction. We find that dynamically-supported topography alone could be sufficient to maintain subaerial land on Earth-size stagnant lid planets with surface water inventories of up to approximately 10−4 times their mass, in the most favourable thermal states. By considering only dynamic topography, which has ~1-km amplitudes on Earth, these results represent a lower limit to the true ocean basin capacity. Our work indicates that deterministic geophysical modelling could inform the variability of land propensity on low-mass planets.
More details from the publisher
Full PDF text
Details from ArXiV

Assimilation of both column‐ and layer‐integrated dust opacity observations in the Martian atmosphere

Earth and Space Science Wiley 8:12 (2021) e2021EA001869

Authors:

Tao Ruan, Rmb Young, Sr Lewis, L Montabone, A Valeanu, Pl Read

Abstract:

A new dust data assimilation scheme has been developed for the UK version of the Laboratoire de Météorologie Dynamique (LMD) Martian General Circulation Model. The Analysis Correction scheme (adapted from the UK Met Office) is applied with active dust lifting and transport to analyze measurements of temperature, and both column-integrated dust optical depth (CIDO), τref (rescaled to a reference level), and layer-integrated dust opacity (LIDO). The results are shown to converge to the assimilated observations, but assimilating either of the dust observation types separately does not produce the best analysis. The most effective dust assimilation is found to require both CIDO (from Mars Odyssey/THEMIS) and LIDO observations, especially for Mars Climate Sounder data that does not access levels close to the surface. The resulting full reanalysis improves the agreement with both in-sample assimilated CIDO and LIDO data and independent observations from outside the assimilated dataset. It is thus able to capture previously elusive details of the dust vertical distribution, including elevated detached dust layers that have not been captured in previous reanalyses. Verification of this reanalysis has been carried out under both clear and dusty atmospheric conditions during Mars Years 28 and 29, using both in-sample and out of sample observations from orbital remote sensing and contemporaneous surface measurements of dust opacity from the Spirit and Opportunity landers. The reanalysis was also compared with a recent version of the Mars Climate Database (MCD v5), demonstrating generally good agreement though with some systematic differences in both time mean fields and day-to-day variability.

More details from the publisher
Details from ORA
More details
More details