Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres

Details Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres

2007-07-11

arxiv.org/abs/0707.1557v1

Astronomy and Astrophysics, Volume 472, Issue 2, pp.665-679, 2007

Astronomy and Astrophysics

Astrophysics

27 pages, 15 figures, Astronomy & Astrophysics accepted

Scientific paper

10.1051/0004-6361:20066663

Previous research has indicated that high amounts of ozone (O3) and oxygen (O2) may be produced abiotically in atmospheres with high concentrations of CO2. The abiotic production of these two gases, which are also characteristic of photosynthetic life processes, could pose a potential "false-positive" for remote-sensing detection of life on planets around other stars.We show here that such false positives are unlikely on any planet that possesses abundant liquid water, as rainout of oxidized species onto a reduced planetary surface should ensure that atmospheric H2 concentrations remain relatively high, and that O2 and O3 remain low. Our aim is to determine the amount of O3 and O2 formed in a high CO2 atmosphere for a habitable planet without life. We use a photochemical model that considers hydrogen (H2) escape and a detailed hydrogen balance to calculate the O2 and O3 formed on planets with 0.2 of CO2 around the Sun, and 0.02, 0.2 and 2 bars of CO2 around a young Sun-like star with higher UV radiation. The concentrations obtained by the photochemical model were used as input in a radiative transfer model that calculated the spectra of the modeled planets. The O3 and O2 concentrations in the simulated planets are extremely small, and unlikely to produce a detectable signature in the spectra of those planets. We conclude that with a balanced hydrogen budget, and for planets with an active hydrological cycle, abiotic formation of O2 and O3 is unlikely to create a possible false positive for life detection in either the visible/near-infrared or mid-infrared wavelength regimes.

Affiliated with

Also associated with

No associations

Rating

Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres 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 Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-434618