Ocean Circulation Affected By Ozone Thinning

Scientists warn that a gap in the Antarctic ozone layer has impacted the way the waters in the southern oceans mix, with the potential to alter the amount of atmospheric CO2 and possibly affect climate change.

Darryn W. Waugh, from the John Hopkins Kriegar School of Arts and Sciences, said: "This may sound entirely academic, but believe me, it's not. This matters because the southern oceans play an important role in the uptake of heat and carbon dioxide, so any changes in southern ocean circulation have the potential to change the global climate."

Stratosphere Changes can Alter Ocean Circulation and Affect Global Climate
Periodic changes in winds 15 to 30 miles high in the stratosphere influence the seas by striking a vulnerable Achilles heel in the North Atlantic, which in turn affect Earth's climate.

Waugh's team used measurements taken from the early 1990s to the mid-to-late 2000s of the amount of a chemical compound known as "chlorofluorocarbon-12," or CFC-12, in the southern oceans, the journal Science reports.

CFC-12 was first produced commercially in the 1930s and its concentration in the atmosphere increased rapidly until the 1990s when it was phased out by the Montreal Protocol on substances that deplete the ozone layer.

Prior to the Montreal Protocol, CFC-12 was used in products such as aerosol hairsprays and refrigerants and in air conditioning systems, according to a Johns Hopkins' statement.

Emissions Abroad may Cause Springtime Ozone Increases Over Western North America
Air flowing eastward from the Pacific Ocean causes a rise in springtime ozone levels above western North America.

From those ocean measurements, Waugh's team was able to infer changes in how rapidly surface waters have mixed into the depths of the southern oceans.

Because they knew that concentrations of CFCs at the ocean surface increased in tandem with those in the atmosphere, they were able to surmise that the higher the concentration of CFC-12 deeper in the ocean, the more recently those waters were at the surface.

Experts Expect Ozone Layer Recovery to Take Four Decades
The World Meteorological Organization (WMO) has said that the ozone layer outside the Polar regions will take four decades to recover to its pre-1980 levels.

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Elevated Springtime Ozone Levels Associated With Emissions from Abroad
In a new study, scientists have pointed out that springtime ozone levels above western North America are increasing mainly due to air flowing eastward from the Pacific Ocean.