Bistability of atmospheric oxygen and the Great Oxidation

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

23

Scientific paper

The history of the Earth has been characterized by a series of major transitions separated by long periods of relative stability. The largest chemical transition was the `Great Oxidation', approximately 2.4 billion years ago, when atmospheric oxygen concentrations rose from less than 10-5 of the present atmospheric level (PAL) to more than 0.01 PAL, and possibly to more than 0.1 PAL. This transition took place long after oxygenic photosynthesis is thought to have evolved, but the causes of this delay and of the Great Oxidation itself remain uncertain. Here we show that the origin of oxygenic photosynthesis gave rise to two simultaneously stable steady states for atmospheric oxygen. The existence of a low-oxygen (less than 10-5 PAL) steady state explains how a reducing atmosphere persisted for at least 300 million years after the onset of oxygenic photosynthesis. The Great Oxidation can be understood as a switch to the high-oxygen (more than 5 × 10-3 PAL) steady state. The bistability arises because ultraviolet shielding of the troposphere by ozone becomes effective once oxygen levels exceed 10-5 PAL, causing a nonlinear increase in the lifetime of atmospheric oxygen. Our results indicate that the existence of oxygenic photosynthesis is not a sufficient condition for either an oxygen-rich atmosphere or the presence of an ozone layer, which has implications for detecting life on other planets using atmospheric analysis and for the evolution of multicellular life.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Bistability of atmospheric oxygen and the Great Oxidation 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 Bistability of atmospheric oxygen and the Great Oxidation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bistability of atmospheric oxygen and the Great Oxidation will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1440119

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.