Why the Southern Hemisphere is stormier than the Northern Hemisphere

About the episode

For centuries, sailors in the world’s oceans have noted that they have to face the worst storms when in the southern hemisphere. Now researchers think they know why it’s stormier there than elsewhere.

Since the 1980s, satellite data has also confirmed that storms in the Southern Hemisphere – where you’ll find Australia and parts of Africa and South America – are more violent than in the Northern Hemisphere. . About 24% more intense, to be more precise.

Researchers at the University of Chicago now think they have an idea why. They combined observations, existing literature and climate models and found two possible causes.

The first: the mountain ranges. In the northern hemisphere, you will find many more. If they removed that in the simulations, the airflow changed and the storm difference in the two hemispheres became much smaller. The other cause: ocean currents. The energy of this current differs per hemisphere. This is because it sinks in the Arctic, crosses the bottom and then rises near Antarctica to continue moving on the surface. If they equalized that current in the simulations, the rest of the storm difference disappeared.

What they also found is that the difference has grown since satellite measurements began in the 1980s. The Southern Hemisphere is getting increasingly stormy. They could link this increase to changes in the oceans. All the knowledge that is important to better estimate and prepare for the consequences of climate change in the future.

Read more: The southern hemisphere is stormier than the north, and we finally know why.