Solar Activity Impacts Polar Ozone and May Influence Climate

As temperatures rise on our planet, greenhouse gases are mostly to blame. Now, scientists have taken a closer look and have found that the sun affects middle atmosphere ozone, which may have potential implications on smaller scale to regional climate.

The amount of greenhouse gases in our atmosphere is certainly affecting our climate. Yet the sun's fluctuations may also be to blame. This climate variability isn't a trend, like climate change, but instead is tied to solar activity fluctuations year-to-year.

Earth's radiation belts are located in near-Earth space. These belts contain vast quantities of solar energetic electrons, which are trapped by Earth's magnetic field. During magnetic storms, which are often caused by solar winds from solar flares or coronal mass ejections, the electrons speed up and enter the atmosphere in the polar regions. In the atmosphere, these electrons ionize gas molecules and create ozone-depleting catalyst gases. This can reduce the ozone in the upper atmosphere as much as 90 percent on a momentary basis.

"The detected ozone variation may in part help understand the alternation of local mild and cold winter seasons, as hints have been obtained in previous research that the ozone changes in the middle atmosphere may link as far as the surface of Earth and affect, among other things, polar wind streams," said Pekka Veronen, one of the researchers, in a news release.

In fact, the researchers found that there are strong effects in the polar latitudes. The amount of ozone at 70 to 90 km altitude can vary more than 30 percent during a solar cycle. This ozone variation is so great that it may likely impact the temperature balance of the atmosphere which, in turn, can affect atmospheric winds.

"These results are only the first step but an important one, allowing us to better understand the long-term impacts of this type of solar activity, and its role in regional climate variability," said Monika Andersson, one of the researchers.

The findings are published in the journal Nature Communications.