We Finally Know Why The Southern Hemisphere Is So Much Stormier

Extreme weather events are not evenly divided between the two parts of the globe. The Southern Hemisphere is stormier than the Northern for a number of reasons.

A new study looking in detail at global storm patterns identifies the heights of mountain ranges and the circulation of energy around the ocean as two primary factors in determining how storms brew above and below the equator.

To reach their conclusions, a team of researchers from the University of Chicago and the University of Washington ran a series of modified climate models, looking at how changing variables had an impact on the number of storms that were created.

Tiffany Shaw, a climate scientist at the University of Chicago, says that instead of putting the Earth in a jar, they use climate models built on the laws of physics.

One part of the climate models was changed at a time. Half of the storminess disappeared when the land mass of the Northern and Southern Hemispheres were flattened.

They put the brakes on the global conveyor belt of ocean current when it cools and sinks in the northern part of the planet. This loss in energy transfer brought storm levels in the two hemispheres into line with each other.

Satellite observations show that the number of storms in the Southern Hemisphere has increased since the 1980s while the Northern Hemisphere has not changed.

Changes in the atmosphere and ocean temperatures are likely to be the reason for that. The loss of sea ice and snow balance out the shifts in the north.

The Southern Hemisphere is projected to become stormier than the Northern Hemisphere due to a tug of war between tropical and polar climates.

After World War II, scientists began to track the weather and climate around the world, even though sailors had known the different conditions in each hemisphere for a long time.

With the arrival of large-scale, real-time satellite imagery at the beginning of the 1980s, researchers were able to obtain a wealth of new information on weather conditions, allowing them to map out and monitor how they were changing over time.

Climate change models will be fed the new findings to help understand how the warming planet might affect storms and weather patterns in the two hemispheres.

Shaw says that laying this foundation of understanding helps society better prepare for the impacts of climate change.

If models are giving us good information now, we can trust what they say about the future. It's important to get the right answer for the right reasons.

The research was published in a journal.