Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets
A possible surface type that may form in the environments of M-dwarf planets is sodium chloride dihydrate, or "hydrohalite" (NaCl $\cdot$ 2H$_2$O), which can precipitate in bare sea ice at low temperatures. Unlike salt-free water ice, hydrohalite is highly reflective in the near-infrared,...
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ftdatacite:10.48550/arxiv.1808.09977 2023-05-15T18:18:46+02:00 Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets Shields, Aomawa L. Carns, Regina C. 2018 https://dx.doi.org/10.48550/arxiv.1808.09977 https://arxiv.org/abs/1808.09977 unknown arXiv https://dx.doi.org/10.3847/1538-4357/aadcaa arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences article-journal Article ScholarlyArticle Text 2018 ftdatacite https://doi.org/10.48550/arxiv.1808.09977 https://doi.org/10.3847/1538-4357/aadcaa 2022-04-01T09:19:22Z A possible surface type that may form in the environments of M-dwarf planets is sodium chloride dihydrate, or "hydrohalite" (NaCl $\cdot$ 2H$_2$O), which can precipitate in bare sea ice at low temperatures. Unlike salt-free water ice, hydrohalite is highly reflective in the near-infrared, where M-dwarf stars emit strongly, making the effect of the interaction between hydrohalite and the M-dwarf SED necessary to quantify. We carried out the first exploration of the climatic effect of hydrohalite-induced salt-albedo feedback on extrasolar planets, using a three-dimensional global climate model. Under fixed CO$_2$ conditions, rapidly-rotating habitable-zone M-dwarf planets receiving 65% or less of the modern solar constant from their host stars exhibit cooler temperatures when an albedo parameterization for hydrohalite is included in climate simulations, compared to simulations without such a parameterization. Differences in global mean surface temperature with and without this parameterization increase as the instellation is lowered, which may increase CO$_2$ build-up requirements for habitable conditions on planets with active carbon cycles. Synchronously-rotating habitable-zone M-dwarf planets appear susceptible to salt-albedo feedback at higher levels of instellation (90% or less of the modern solar constant) than planets with Earth-like rotation periods, due to their cooler minimum day-side temperatures. These instellation levels where hydrohalite seems most relevant correspond to several recently-discovered potentially habitable M-dwarf planets, including Proxima Centauri b, TRAPPIST-1e, and LHS 1140b, making an albedo parameterization for hydrohalite of immediate importance in future climate simulations. : 12 pages, 4 figures, 1 table, accepted for publication in the Astrophysical Journal Text Sea ice DataCite Metadata Store (German National Library of Science and Technology) |
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Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences |
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Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences Shields, Aomawa L. Carns, Regina C. Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets |
topic_facet |
Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences |
description |
A possible surface type that may form in the environments of M-dwarf planets is sodium chloride dihydrate, or "hydrohalite" (NaCl $\cdot$ 2H$_2$O), which can precipitate in bare sea ice at low temperatures. Unlike salt-free water ice, hydrohalite is highly reflective in the near-infrared, where M-dwarf stars emit strongly, making the effect of the interaction between hydrohalite and the M-dwarf SED necessary to quantify. We carried out the first exploration of the climatic effect of hydrohalite-induced salt-albedo feedback on extrasolar planets, using a three-dimensional global climate model. Under fixed CO$_2$ conditions, rapidly-rotating habitable-zone M-dwarf planets receiving 65% or less of the modern solar constant from their host stars exhibit cooler temperatures when an albedo parameterization for hydrohalite is included in climate simulations, compared to simulations without such a parameterization. Differences in global mean surface temperature with and without this parameterization increase as the instellation is lowered, which may increase CO$_2$ build-up requirements for habitable conditions on planets with active carbon cycles. Synchronously-rotating habitable-zone M-dwarf planets appear susceptible to salt-albedo feedback at higher levels of instellation (90% or less of the modern solar constant) than planets with Earth-like rotation periods, due to their cooler minimum day-side temperatures. These instellation levels where hydrohalite seems most relevant correspond to several recently-discovered potentially habitable M-dwarf planets, including Proxima Centauri b, TRAPPIST-1e, and LHS 1140b, making an albedo parameterization for hydrohalite of immediate importance in future climate simulations. : 12 pages, 4 figures, 1 table, accepted for publication in the Astrophysical Journal |
format |
Text |
author |
Shields, Aomawa L. Carns, Regina C. |
author_facet |
Shields, Aomawa L. Carns, Regina C. |
author_sort |
Shields, Aomawa L. |
title |
Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets |
title_short |
Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets |
title_full |
Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets |
title_fullStr |
Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets |
title_full_unstemmed |
Hydrohalite Salt-albedo Feedback Could Cool M-dwarf Planets |
title_sort |
hydrohalite salt-albedo feedback could cool m-dwarf planets |
publisher |
arXiv |
publishDate |
2018 |
url |
https://dx.doi.org/10.48550/arxiv.1808.09977 https://arxiv.org/abs/1808.09977 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
https://dx.doi.org/10.3847/1538-4357/aadcaa |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1808.09977 https://doi.org/10.3847/1538-4357/aadcaa |
_version_ |
1766195455311478784 |