scholarly journals Stabilization of Dayside Surface Liquid Water via Tropopause Cold Trapping on Arid Slowly Rotating Tidally Locked Planets

2020 ◽  
Vol 891 (1) ◽  
pp. L18 ◽  
Author(s):  
Feng Ding ◽  
Robin D. Wordsworth
Keyword(s):  
Liquid Water ◽  
Surface Liquid

scholarly journals Carbonate-silicate cycle predictions of Earth-like planetary climates and testing the habitable zone concept

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Owen R. Lehmer ◽  
David C. Catling ◽  
Joshua Krissansen-Totton
Keyword(s):  
Liquid Water ◽  
Physicochemical Parameters ◽  
Silicate Weathering ◽  
Habitable Zone ◽  
Two Dimensional ◽  
Land Area ◽  
Incident Flux ◽  
Earth Like Planets ◽  
Surface Liquid ◽  
Log Linear

AbstractIn the conventional habitable zone (HZ) concept, a CO2-H2O greenhouse maintains surface liquid water. Through the water-mediated carbonate-silicate weathering cycle, atmospheric CO2 partial pressure (pCO2) responds to changes in surface temperature, stabilizing the climate over geologic timescales. We show that this weathering feedback ought to produce a log-linear relationship between pCO2 and incident flux on Earth-like planets in the HZ. However, this trend has scatter because geophysical and physicochemical parameters can vary, such as land area for weathering and CO2 outgassing fluxes. Using a coupled climate and carbonate-silicate weathering model, we quantify the likely scatter in pCO2 with orbital distance throughout the HZ. From this dispersion, we predict a two-dimensional relationship between incident flux and pCO2 in the HZ and show that it could be detected from at least 83 (2σ) Earth-like exoplanet observations. If fewer Earth-like exoplanets are observed, testing the HZ hypothesis from this relationship could be difficult.

scholarly journals Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet

2021 ◽  
Vol 15 (2) ◽  
pp. 571-593
Author(s):  
Marion Donat-Magnin ◽  
Nicolas C. Jourdain ◽  
Christoph Kittel ◽  
Cécile Agosta ◽  
Charles Amory ◽  
...  
Keyword(s):  
Mass Balance ◽  
Liquid Water ◽  
Ice Sheet ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Ice Shelves ◽  
Net Production ◽  
West Antarctic ◽  
Surface Liquid ◽  
Surface Melt

Abstract. We present projections of West Antarctic surface mass balance (SMB) and surface melt to 2080–2100 under the RCP8.5 scenario and based on a regional model at 10 km resolution. Our projections are built by adding a CMIP5 (Coupled Model Intercomparison Project Phase 5) multi-model-mean seasonal climate-change anomaly to the present-day model boundary conditions. Using an anomaly has the advantage to reduce CMIP5 model biases, and a perfect-model test reveals that our approach captures most characteristics of future changes despite a 16 %–17 % underestimation of projected SMB and melt rates. SMB over the grounded ice sheet in the sector between Getz and Abbot increases from 336 Gt yr−1 in 1989–2009 to 455 Gt yr−1 in 2080–2100, which would reduce the global sea level changing rate by 0.33 mm yr−1. Snowfall indeed increases by 7.4 % ∘C−1 to 8.9 % ∘C−1 of near-surface warming due to increasing saturation water vapour pressure in warmer conditions, reduced sea-ice concentrations, and more marine air intrusion. Ice-shelf surface melt rates increase by an order of magnitude in the 21st century mostly due to higher downward radiation from increased humidity and to reduced albedo in the presence of melting. There is a net production of surface liquid water over eastern ice shelves (Abbot, Cosgrove, and Pine Island) but not over western ice shelves (Thwaites, Crosson, Dotson, and Getz). This is explained by the evolution of the melt-to-snowfall ratio: below a threshold of 0.60 to 0.85 in our simulations, firn air is not entirely depleted by melt water, while entire depletion and net production of surface liquid water occur for higher ratios. This suggests that western ice shelves might remain unaffected by hydrofracturing for more than a century under RCP8.5, while eastern ice shelves have a high potential for hydrofracturing before the end of this century.

scholarly journals On the probability of habitable planets

2013 ◽  
Vol 12 (3) ◽  
pp. 177-185 ◽  
Author(s):  
François Forget
Keyword(s):  
Liquid Water ◽  
Climate Models ◽  
Climatic Conditions ◽  
Point Of View ◽  
Habitable Zone ◽  
One Dimensional ◽  
The Past ◽  
Surface Liquid ◽  
New Generation ◽  
Global Mean

AbstractIn the past 15 years, astronomers have revealed that a significant fraction of the stars should harbour planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e. suitable for life and its evolution? These questions have been discussed for years and we are slowly making progress. Liquid water remains the key criterion for habitability. It can exist in the interior of a variety of planetary bodies, but it is usually assumed that liquid water at the surface interacting with rocks and light is necessary for emergence of a life able to modify its environment and evolve. The first key issue is thus to understand the climatic conditions allowing surface liquid water assuming a suitable atmosphere. These have been studied with global mean one-dimensional (1D) models which have defined the ‘classical habitable zone’, the range of orbital distances within which worlds can maintain liquid water on their surfaces (Kasting et al. 1993). A new generation of 3D climate models based on universal equations and tested on bodies in the solar system are now available to explore with accuracy climate regimes that could locally allow liquid water. The second key issue is now to better understand the processes which control the composition and the evolution of the atmospheres of exoplanets, and in particular the geophysical feedbacks that seem to be necessary to maintain a continuously habitable climate. From that point of view, it is not impossible that the Earth's case may be special and uncommon.

scholarly journals Why Geosciences and Exoplanetary Sciences Need Each Other

Elements ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. 229-234
Author(s):  
Oliver Shorttle ◽  
Natalie R. Hinkel ◽  
Cayman T. Unterborn
Keyword(s):  
Solar System ◽  
Liquid Water ◽  
Plate Tectonics ◽  
Earth Observations ◽  
The Earth ◽  
Surface Liquid ◽  
Insight Into

The study of planets outside our Solar System may lead to major advances in our understanding of the Earth and may provide insight into the universal set of rules by which planets form and evolve. To achieve these goals requires applying geoscience’s wealth of Earth observations to fill in the blanks left by the necessarily minimal exoplanetary observations. In turn, many of Earth’s one-offs—plate tectonics, surface liquid water, a large moon, and life: long considered as “Which came first?” conundrums for geoscientists—may find resolution in the study of exoplanets that possess only a subset of these phenomena.

Anomalous region on Mars: implications for near-surface liquid water

Nature ◽  
1980 ◽  
Vol 288 (5787) ◽  
pp. 126-129 ◽  
Author(s):  
S. H. Zisk ◽  
P. J. Mouginis-Mark
Keyword(s):  
Liquid Water ◽  
Near Surface ◽  
Surface Liquid ◽  
Anomalous Region

scholarly journals Tidal evolution in multiple planet systems: application to Kepler-62 and Kepler-186

2014 ◽  
Vol 9 (S310) ◽  
pp. 58-61
Author(s):  
Emeline Bolmont ◽  
Sean N. Raymond ◽  
Jérémy Leconte ◽  
Alexandre Correia ◽  
Elisa Quintana
Keyword(s):  
Liquid Water ◽  
Dynamical Evolution ◽  
Habitable Zone ◽  
Tidal Evolution ◽  
Surface Liquid

AbstractA large number of observed exoplanets are part of multiple planet systems. Most of these systems are sufficiently close-in to be tidally evolving. In such systems, there is a competition between the excitation caused by planet-planet interactions and tidal damping. Using as an example two multiple planet systems, which host planets in the surface liquid water habitable zone (HZ): Kepler-62 and Kepler-186, we show the importance and effect of both planetary and stellar tides on the dynamical evolution of planets and on the climate of the HZ planets.

scholarly journals Early oxidation of the martian crust triggered by impacts

2020 ◽  
Vol 6 (44) ◽  
pp. eabc4941
Author(s):  
Zhengbin Deng ◽  
Frédéric Moynier ◽  
Johan Villeneuve ◽  
Ninna K. Jensen ◽  
Deze Liu ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Liquid Water ◽  
Water Reservoir ◽  
Warm Climate ◽  
Oxygen Isotopic ◽  
Water On Mars ◽  
Surface Liquid ◽  
Impact Melts ◽  
Martian Regolith ◽  
Standing Question

Despite the abundant geomorphological evidence for surface liquid water on Mars during the Noachian epoch (>3.7 billion years ago), attaining a warm climate to sustain liquid water on Mars at the period of the faint young Sun is a long-standing question. Here, we show that melts of ancient mafic clasts from a martian regolith meteorite, NWA 7533, experienced substantial Fe-Ti oxide fractionation. This implies early, impact-induced, oxidation events that increased by five to six orders of magnitude the oxygen fugacity of impact melts from remelting of the crust. Oxygen isotopic compositions of sequentially crystallized phases from the clasts show that progressive oxidation was due to interaction with an 17O-rich water reservoir. Such an early oxidation of the crust by impacts in the presence of water may have supplied greenhouse gas H2 that caused an increase in surface temperature in a CO2-thick atmosphere.

scholarly journals Dual Frequency Orbiter-Radar System for the Observation of Seas and Tides on Titan: Extraterrestrial Oceanography from Satellite

2019 ◽  
Vol 11 (16) ◽  
pp. 1898
Author(s):  
Marco Mastrogiuseppe
Keyword(s):  
Liquid Water ◽  
Liquid Hydrocarbon ◽  
Radar System ◽  
Global Ocean ◽  
Dual Frequency ◽  
Love Number ◽  
Tidal Amplitude ◽  
Surface Liquid ◽  
Extraterrestrial Oceanography ◽  
Ice Shell

Saturn’s largest moon, Titan, is believed to have a ~100 km thick ice shell above a global ocean of liquid water. Organic materials, including liquid hydrocarbon lakes and seas in its polar terrain, cover Titan’s surface, which makes it a world of two oceans. The RADAR instrument on board Cassini, was able to probe lakes and seas during few dedicated altimetric observations, revealing its capability to work as a sounder. Herein, we describe the design of, and scientific motivation for, a dual frequency X/Ka-band radar system that is able to investigate Titan’s subsurface liquid water ocean, as well as the depth and composition of its surface liquid hydrocarbon basins. The proposed system, which could take advantage of the telecommunications dish, can operate as a sounder, as Synthetic Aperture Radar (SAR) able to map the surface at tens meters of scale resolution, and when data are acquired from close-adjacent orbits, as a repeat-pass SAR interferometer (InSAR). The instrument, which is based on the architecture of the Cassini RADAR, can also characterize Titan’s interior by using geophysical measurements of the tidal amplitude to derive high accuracy estimates of the Love number h2 from a 1500 km circular orbit.

scholarly journals Sulfate Aerosol Hazes and SO2 Gas as Constraints on Rocky Exoplanets’ Surface Liquid Water

2019 ◽  
Vol 887 (2) ◽  
pp. 231 ◽  
Author(s):  
Kaitlyn Loftus ◽  
Robin D. Wordsworth ◽  
Caroline V. Morley
Keyword(s):  
Liquid Water ◽  
Sulfate Aerosol ◽  
Surface Liquid ◽  
So2 Gas
Sign in / Sign up

Export Citation Format

Share Document