Ozone hole linked to deterioration of Southern Ocean carbon sink

By Noreen Parks

In addition to weakening Earth’s natural shield against excessive radiation levels, ozone depletion above Antarctica has significantly dampened the Southern Ocean’s ability to absorb atmospheric CO2 and has accelerated acidification of southern polar waters, according to new research reported online June 20 in Geophysical Research Letters (2009, DOI 10.1029/2009GL038227). Of the atmospheric CO2 generated by humans and absorbed by the world’s oceans, more than 40% is believed to be taken up by the Southern Ocean; this makes that body of water one of the planet’s major carbon sinks. Global climate models have predicted that southern polar waters would compensate for the steadily rising CO2 levels by soaking up the greenhouse gas. However, recent studies based on shipboard measurements have revealed declining CO2 uptake in those waters. Scientists have posited that intensified westerly winds caused by the ozone hole drive surface water to mix with deeper, CO2-rich water, thus limiting the ocean’s capacity to draw the gas down from the atmosphere. …

Ozone hole linked to deterioration of Southern Ocean carbon sink.