Stratospheric ozone chemistry plays an important role for atmospheric airflow patterns

Washington, March 9 : Using climate simulations, scientists have determined that interactions between the stratospheric ozone chemistry and atmospheric air flow lead to significant changes of airflow patterns from the ground up to the stratosphere.

Developed by scientists at the Research Unit Potsdam of the Alfred Wegener Institute for Polar and Marine Research in Germany, the simulations are a result of the investigation of a fundamental process for climate interactions in the Arctic.

It is not known what causes natural variations of atmospheric air flow patterns which have been playing an important role for climate changes in the last decades. This basic knowledge is necessary to improve climate models that still hold much uncertainty.

So far, feedbacks between chemical processes in the stratosphere and the circulation in the troposphere and stratosphere are not included in complex global climate models linking atmosphere and ocean.

For the first time, scientists from the Alfred Wegener Institute have included a module of stratospheric ozone chemistry into a coupled global climate model.

The scientists show that ozone chemistry significantly influences the Artic Oscillation by comparing simulations of the standard model with results from the model extended by the new ozone chemistry module.

It has been shown that changes of atmospheric air flows and temperature distribution lead to an increase of the negative phase of the Artic Oscillation during the winter seasons.

The results also indicated that if interactions between atmospheric air flow and stratospheric ozone chemistry are being taken into account, they will also have an influence on the stability of the polar vortex in the simulation of future climate developments and should therefore be included in climate models.

"Our research is an important contribution to reduce the uncertainty in the simulation of today's climate," said Sascha Brand of the Alfred Wegener Institute, main author of the published study.

"Today's climate models carry, contrary to many claims, still a high level of uncertainty. Only by understanding the basic processes in the Arctic, can we quantify these deviations and eliminate them," he added.

In a follow-up project, the new model will be used for the calculation of future climate developments.

ANI