Accumulation of Atmospheric Oxygen due to Water Photolysis and Hydrogen Escape.

Overview

Track water loss and oxygen build-up due to hydrodynamic atmospheric escape.

Date

07/25/18

Author

Rodrigo Luger

Modules

AtmEsc STELLAR

Approx. runtime

10 minutes

Water-rich terrestrial planets orbiting low mass stars may experience sustained bombardment by XUV photons during the pre-main sequence phase of the host star. As the planets will likely be in a runaway greenhouse, water can reach the stratosphere where it is photolyzed. Hydrogen can then escape leaving behind the heavier oxygen. This script reproduces Figure 7 in Luger and Barnes (2015).

To run this example

Note

You might need to install tqdm:

pip install tqdm

python makeplot.py <pdf | png>

Expected output

examples/AbioticO2.png

Water loss and oxygen accumulation for planets orbiting in the habitable zones of M dwarfs. The extended pre-main sequence phase of low mass stars leads to vigorous hydrodynamic escape from planets in their habitable zones, causing the loss of surface water (left) and the accumulation of atmospheric oxygen (right). See Luger and Barnes (2015) for more details.