News Climate

Weather patterns over Southern Hemisphere have a regular pulse

Atmospheric cycle 20 to 30 days long is first one found outside tropics

UPS AND DOWNS  Clouds and clear skies appear over the southern midlatitudes in this weather visualization. Storminess and rainfall in the region cycles up and down every 20 to 30 days.

Goddard Space Flight Center Scientific Visualization Studio/NASA

By Gabriel Popkin

- More than 2 years ago

Variations in rainfall and storm intensity over a broad swath of the Southern Hemisphere follow a pattern that repeats every 20 to 30 days.