Mathematics – Logic
Scientific paper
May 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011aas...21840207h&link_type=abstract
American Astronomical Society, AAS Meeting #218, #402.07; Bulletin of the American Astronomical Society, Vol. 43, 2011
Mathematics
Logic
Scientific paper
A group of microorganisms can disproportionate sulfite and elemental sulfur into sulfide and sulfate to obtain energy for a living. We explore if the sulfide produced by microorganisms can alter the atmospheric composition to manifest in the spectrum of a habitable exoplanet. We consider a dry (i.e., limited ocean cover) habitable planet of Earth size and mass, orbiting a Sun-like star. As on Earth, volcanoes release sulfur as sulfur dioxide and hydrogen sulfide, but the volcanic production of hydrogen sulfide is limited by the scarcity of water. In the meantime, in our scenario, microbes can flourish in the ocean and effectively make use of the energy gained from the sulfur disproportion and release sulfide as the metabolic byproduct. The metabolic sulfur disproportion can enhance the overall outgassing rate of hydrogen sulfide by nearly one order of magnitude over the non-biological emission. To study the atmospheric response to this enhancement, we build a one-dimensional chemical transport model that treats all O, H and S bearing species and the relevant photochemical and chemical reactions. The vertical transport is approximated with the eddy diffusion. We also consider the formation and the sedimentation of elemental sulfur aerosols and sulfate aerosols in the atmosphere and explore the effect of aerosol particle size on the chemistry and the radiative transfer. To establish hydrogen sulfide as a biosignature, we need to understand the atmospheric response to the sulfide outgassing, the spectral features of hydrogen sulfide and its photochemical products, and the volcanic release of H2S. The current work will address the first two problems, and the main uncertainty will remain at the possible false positives due to the volcanism.
Bains William
Hu Renyu
Seager Sara
No associations
LandOfFree
Can Hydrogen Sulfide Gas Be a Biosignature in a Habitable Exoplanet? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Can Hydrogen Sulfide Gas Be a Biosignature in a Habitable Exoplanet?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Can Hydrogen Sulfide Gas Be a Biosignature in a Habitable Exoplanet? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1743072