Research reveals ozone in the atmosphere has weakened one of the Earth’s main cooling mechanisms
According to new NSF funded research, ozone levels in the upper and lower atmosphere were responsible for almost a third of the warming seen in ocean waters bordering Antarctica in the second half of the 20th century.
These levels also may be weakening one of Earth’s most important cooling mechanisms, making it a more significant greenhouse gas than previously thought.
What are the full dangers of ozone, the greenhouse gas?
The greenhouse gas ozone is considered a danger, with even relatively low ozone levels in the air can be harmful to human health. Ozone is one of the key components of smog and is already considered a hazardous pollutant, however, research shows it may also play a significant role in driving climate change in the coming years.
Created in the upper atmosphere by the interaction of oxygen molecules and UV radiation from the sun, and by chemical reactions between pollutants such as vehicle exhaust fumes in the lower atmosphere.
Ozone close to Earth’s surface is harmful to people and the environment, but this study reveals that it also has a big impact on the ocean’s ability to absorb excess heat from the atmosphere.
Deep and rapid changes in the Southern Ocean, as it soaks up warming
The Southern Ocean has been experiencing deep and rapid warming effects, as it continues its role as one of the main regions for soaking up excess heat as the planet warms.
Researchers have discovered that the majority of this warming can be attributed to ozone increases in the lower atmosphere.
“This study highlights the complexity of the atmosphere-ocean interactions that play a role in Earth’s heat balance, and the need for continued observations of the atmosphere-ocean system and reliable models to simulate these processes,” said Sean Kennan, a program director in NSF’s Division of Ocean Sciences.
By simulating changes in ozone levels in the upper and lower atmosphere between 1955 and 2000, researchers from the University of California, Riverside were able to isolate the way in which the levels affected warming and increase the current understanding of ozone’s impact on the Southern Ocean heat uptake.
“This study highlights the complexity of the atmosphere-ocean interactions that play a role in Earth’s heat balance, and the need for continued observations of the atmosphere-ocean system and reliable models to simulate these processes,” said Sean Kennan, a program director in NSF’s Division of Ocean Sciences.
Simulations show how decrease in ozone impact the ocean
The simulations showed that a decrease in ozone in the upper atmosphere and increase in the lower atmosphere both contributed to ocean warming seen in upper ocean waters at high latitudes.
The study revealed that the increased ozone in the lower atmosphere caused 60% of the overall ozone-induced warming seen in the Southern Ocean over the period studied – far more than previously thought.
Increased ozone in the lower atmosphere caused 60% of the overall ozone-induced warming
Changes in ozone concentrations in the atmosphere affect westerly winds in the Southern Hemisphere and causes contrasting levels of salt and temperature close to the surface in the Southern Ocean. Both affect ocean currents in distinct ways, thereby affecting ocean heat uptake.
