North of the equator, April showers bring May flowers. But in the Southern Hemisphere, April droughts bring doubts.
Since the 1970s, southern Australia — and other areas of the Southern Hemisphere —have seen decreased levels of rain between April and May, which is autumn in that part of the Earth. But what's causing this extended drought?
Previous research has pointed the finger at a southward shift in storm tracks and weather systems during the late 20th century.
But a study published today (Oct. 4) in the journal Scientific Reports takes the explanation one step further. Its findings suggest that changing storm patterns and the ensuing droughts are due to a southern shift in the Hadley cell, the large-scale pattern of atmospheric circulation that transports heat from the tropics to the subtropics.