Weather experts have discovered large 'rivers' in the Kenyan sky that carry away water vapour from northern Kenya and channel it to Congo, where it rains heavily.
These rivers appear partly responsible for the long dry periods witnessed in Kenya over the last three years, they said.
In Northern Kenya, it is currently raining, after more than five seasons without rain.
The researchers explained these 'rivers' in the sky are actually strong winds that carry millions of tonnes of water vapour, the key ingredient in rainfall.
They are triggered by the deep valleys of the Rift Valley in places such as Turkana.
“These valleys, including the Turkana Basin in Kenya, cause East Africa to dry by channelling water vapour towards Central Africa, a process that simultaneously enhances rainfall in the Congo Basin rainforest,” they said in a paper published by the Nature Journal.
“Without the valleys, the uplift of the rift system leads to a wetter climate in East Africa and a drier climate in the Congo Basin.”
The researchers are from Oxford University. In April 2021, they joined a team from the Kenyan Meteorological Department to Northwest Kenya for a month to release more than 200 weather balloons to sample the river for the very first time.
The Nature paper is titled, 'Valley formation aridifies East Africa and elevates Congo Basin rainfall.'
The university sent a separate statement explaining the finding.
Co-author of the paper, Prof Richard Washington, said, “The experiments show the valleys affect climate on a continental scale. It can’t rain equally everywhere, and the valleys help to sustain high rainfall in the Congo Basin, while leaving East Africa prone to drought.”
One of the largest of these rivers flows across northwest Kenya. This river — which they named ‘Turkana Jet’ — carries water vapour from its source in the Indian Ocean across the arid plains of East Africa to support the great Congo Basin rainforest.
The researchers suggested that this river carries as much as a five times as much water as the Congo River — the second-largest river in Africa.
This makes East Africa much drier than other tropical land regions, including the Amazon and Congo rainforests.
The statement also quotes Dr Callum Munday, who led the study. “Normally, when we think of valleys and water, we think of the rivers that flow along the ground. In East Africa, deep valleys, such as the Turkana Valley, channel strong winds and create invisible rivers in the sky. These invisible rivers carry millions of tonnes of water vapour, the key ingredient for rainfall.”
There are no Kenyans credited as co-authors in the report, which names Callum Munday, Nicholas Savage, Richard G. Jones and Richard Washington as the authors.
Northern Kenya is expected to receive depressed rains between March and May, marking the sixth straight season without adequate rains.
This has also led to high food prices, currently affecting the whole country.
The Food Security Monitor report released by the Alliance for a Green Revolution in Africa (AGRA) this week showed slight improvements in food insecurity across the dry areas due to the impact of the current rains.
“These improvements are expected to last a limited time with the situation projected to deteriorate from March to June 2023,” the report read.
The food security report further showed that there has been an increase in the prices of basic food items and the number of people who cannot produce and or cannot afford food has also increased.
The report showed that much of the East African region continues to experience atypically high food prices due to worsening macroeconomic conditions and persistently low domestic cereal supplies.
In Kenya, overall maize prices in Eldoret and Nakuru are lower than they were one to three months ago. In addition, maize prices were also down 22.57 per cent in Nakuru compared to six months ago.
“These price declines were due to a surplus of about 6.7 million bags based on carryover stocks of 14.2 million bags, an estimated 400,000 bags to be imported from the region by private sector and two million outside of Comesa,” AGRA said in the report.
(Edited by V. Graham)
