[deleted]

Louise Lerner, 5 December 2022.

Excerpt:

>For a long time, we didn’t know very much about the weather in the Southern Hemisphere: most of the ways we observe weather are land-based, and the Southern Hemisphere has much more ocean than the Northern Hemisphere does.

>But with the advent of satellite-based global observing in the 1980s, we could quantify just how extreme the difference was. The Southern Hemisphere has a stronger jet stream and more intense weather events.

>[The authors] used a numerical model of Earth’s climate built on the laws of physics that reproduced the observations. Then they removed different variables one at a time, and quantified each one’s impact on storminess.

> 

>The first variable they tested was topography. Large mountain ranges disrupt air flow in a way that reduces storms, and there are more mountain ranges in the Northern Hemisphere.

>The other half had to do with ocean circulation. Water moves around the globe like a very slow but powerful conveyor belt: it sinks in the Arctic, travels along the bottom of the ocean, rises near Antarctica and then flows up near the surface, carrying energy with it. This creates an energy difference between the two hemispheres.

>The Southern Hemisphere storminess changes were connected to changes in the ocean. They found a similar ocean influence is occurring in the Northern Hemisphere, but its effect is canceled out by the absorption of sunlight in the Northern Hemisphere due to the loss of sea ice and snow.

>The scientists checked and found that models used to forecast climate change as part of the Intergovernmental Panel on Climate Change assessment report were showing the same signals—increasing storminess in the Southern Hemisphere and negligible changes in the Northern—which serves as an important independent check on the accuracy of these models.

Proceedings of the National Academy of Sciences, 2022. DOI 10.1073/pnas.2123512119

You’re welcome southern hemisphere

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/r/MapsWithoutNZ

You would think an article on storms in the southern hemisphere, would include a map with all the countries in the southern hemisphere, particularly considering New Zealand has mountain ranges that would affect this weather phenomena.

Oceans cover 81% of the southern hemisphere and 60% of the northern. It's a big difference.

Do it might not be global warming but tectonic shift.