May 11, 2020

Dipole causes extreme rainfall

Dipole causes extreme rainfall

Last January it rained more than twice as much as usual in our project area in Kuku, Kenya: 91 mm instead of the regular 40 mm. This excessive rainfall was caused by an unusually strong Indian Ocean Dipole (also known as the Indian Niño). Read all about how this dipole works!

The Indian Ocean Dipole

Due to the Indian Ocean Dipole there has been a lot of rainfall in the eastern part of Africa during the last short rainy season from November till February. But how does this rain arise? 

An ocean dipole occurs when the surface of the ocean warms up one side while simultaneously cooling down at the other side. The result? Due to the warming up of the water, more moisture gets into the air. This leads to extensive cloud formation. Eventually, these clouds cause lots of rain.  

This process has taken place during the short rainy season in the eastern part of Africa. Due to the Indian Ocean Dipole, the water in the ocean next to East Africa has warmed up extensively. And that means: lots of rain in this area, including Kenya.

The consequences

This large amount of rain unfortunately causes serious floods, especially in the lower areas. Luckily, due to the bunds we’ve been digging, a lot of the rainwater has been captured. This means more regreening and less flooding!  See below the beautiful result of this rain: even outside the bunds, vegetation has grown.