On Atmospheric Loss of Oxygen Ions from Earth Through Magnetospheric Processes

• DOI: 10.1126/science.1058913
• Publication Date: 2002-07-27T09:48:21Z
• Authors: K. Seki; R. C. Elphic; M. Hirahara; T. Terasawa; T. Mukai
• Keywords: 13. Climate action; 01 natural sciences; 7. Clean energy; 0105 earth and related environmental sciences

In Earth's environment, the observed polar outflow rate for O + ions, the main source of oxygen above gravitational escape energy, corresponds to the loss of ∼18% of the present-day atmospheric oxygen over 3 billion years. However, part of this apparent loss can actually be returned to the atmosphere. Examining loss rates of four escape routes with high-altitude spacecraft observations, we show that the total oxygen loss rate inferred from current knowledge is about one order of magnitude smaller than the polar O + outflow rate. This disagreement suggests that there may be a substantial return flux from the magnetosphere to the low-latitude ionosphere. Then the net oxygen loss over 3 billion years drops to ∼2% of the current atmospheric oxygen content.