THE STRANGE INDIAN OCEAN event causing heavy rains in Kenya

As a young post-doc fellow at a university in Japan, in 1998, Saji Hameed was puzzled by strange events that had taken place four years earlier. The 1994 summer (June-September) had been unusually hot in Japan, and researchers were still unable to identify the cause. Later that year, an Indian Ocean surface current that moves from west to east had reversed and moved in the opposite direction.

Saji and his colleagues finally unravelled the mystery in 1999. They discovered the events were triggered by unique air-sea interactions in the Indian Ocean, causing the ocean’s surface to cycle between cold and warm. They called the phenomenon the Indian Ocean Dipole (IOD). The cycle rotates around positive, negative and neutral. The extremely dry weather in Japan was caused by a positive IOD, which, on the other hand, dumps unusually heavy rains on East Africa.

Animation by Lucy Swan, sound design by Eric Thuo

Animation by Lucy Swan, sound design by Eric Thuo

Saji recently warned a positive IOD was back and would peak in November, leading to heavier rains in Kenya and other East African countries. During a positive IOD, sea surface temperatures in the Indian Ocean near Africa's east coast are warmer than usual, and that evaporation is dumped inside Eastern Africa in form of excessive rains. In September, Saji told Weather.com that positive IODs tend to occur every 10 years.

INDIAN OCEAN DIPOLE INDEX 2015 - 2019

*Australian Government Bureau of Meteorology

*Australian Government Bureau of Meteorology

 “I mostly fear about the situation in East Africa, which is vulnerable even without an adverse climate event. We are talking about millions of people being displaced, emergence of Rift Valley fever and other flood-related issues as experienced during the strong IOD of 2006,” he said.

The Kenya Meteorological Department has also attributed the ongoing heavy rains to the dipole. The department said the rains would be heaviest in November, and could cause destruction and deaths. “This constitutes a positive Indian Ocean Dipole that is favourable for good rainfall over much of East Africa,” said Met director Stella Aura. “In Western Kenya, where enhanced rainfall is expected, lightning strikes may occur, especially in counties such as Kisii, Kisumu, Kakamega and Bungoma [Mt Elgon areas]. Cases of flooding are also highly probable.”

By October 21, the heavy rains in Kenya had displaced at least 1,000 people and left at least 10 dead. In Baringo, leaders warned residents living in lower areas to move to higher ground to prevent deaths due to floods and landslides. Governor Stanley Kiptis urged residents living on the flat and hilly sides of Baringo South, Mogotio, Baringo North, Tiaty, Baringo Central and Eldama Ravine subcounties to take precaution. Other areas that suffer perennial floods and landslides are Sintaan, Ng’ambo in Marigat bordering Lake Baringo, and Kabasis, Salawa, Tenges and Timoboiwo in Baringo Central. “I want to urge my people to be watchful and tell others we are not ready to lose anybody because we heard the rain may continue until December,” Kiptis told the Star.

In Busia, county commissioner Jacob Narengo said the rains were becoming more dangerous and disastrous, and urged the disaster management committee to ensure no family lives along riverbanks. He spoke during Mashujaa Day celebrations at Kolanya Primary School, Teso. In Teso North and South in Busia county, more than 400 families need relief food after their homes, crops and animals were swept away by floodwaters. This was after the rivers Malakisi and Ang’olol broke their banks. Villages that have been hard hit by flash floods include Akiriamasit, Amoni, Onyunyur, Kamolo and Buria. Teachers were forced to close schools.

In Mandera, the heavy rains have caused Sh2 billion losses. Governor Ali Roba told the Star livestock have been killed and dams, water pans, properties, roads and underground tanks destroyed. “While we may not be able to correct all of the above to [their] original position, certainly we will respond to mitigate the impacts and reduce the severity of the negative impacts on humans,” he said.

In Wajir, leaders raised the alarm after one person and at least 900 animals died. Some of the worst-hit areas include Wargadud in Tarbaj subcounty, Elnoor in Eldas subcounty and Gurar, Adadijole, Dinikhu and Bosicha in Wajir North.

In Nyeri, county commissioner David Kipkemei urged people living in areas prone to landslides to move to safer areas. “Let us be keen so we don't lose lives and property,” he said.

When Dr Saji introduced the world to the IOD through a research paper, ‘A dipole mode in the tropical Indian Ocean', in the Nature Journal in 1999, the scientific community scoffed at the idea. Most climate scientists had written off the Indian Ocean as capable of generating its own climate mode. Ten years later, Dr Saji’s paper had become one of the most cited papers in climate science. In 2009, Dr Saji said by understanding the IOD, countries such as Kenya could forestall disasters.

“The disastrous consequences of severe floods that displaced nearly two million people in East Africa and the severe drought that caused widespread wildfires in Indonesia and Malaysia, besides triggering unprecedented haze in neighboring countries during an IOD event in 2006, could have been managed better if the event was predicted in advance and affected countries were alerted to its possible impacts,” he told the Science Watch Magazine in September, 2009.

*UNOCHA

*UNOCHA

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AREAS AFFECTED

Unusually heavy rainfall & flooding in large areas of East Africa have affected at least 2.5 million people since July, according to UNOCHA

*UNOCHA

*UNOCHA

PEOPLE AFFECTED

South Sudan has experienced the worst of the flooding so far, with 908,000 people affected. Flooding has resulted in displacement & loss of livestock

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*UNOCHA

*UNOCHA

CHOLERA CASES

4,554 cases of cholera have been confirmed in Kenya this year. The risk of cholera is heightened by flooding, due to water contamination

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*UNOCHA

*UNOCHA

Across East Africa, the heavy rains have affected more than 2.5 million people, causing displacement and loss of property, crops and livestock, according to ReliefWeb, the world’s largest humanitarian information portal. 

In South Sudan, since July, floods have devastated large areas, affecting more than 908,000 people, 420,000 of whom still need urgent humanitarian assistance. “In Ethiopia, an estimated 570,000 people have been affected, including over 202,000 people displaced,” ReliefWeb says in its October report. The figures have likely gone up. In Sudan, about 346,300 people were affected by flooding in July and August. The rains and stagnant water have led todisease outbreaks, including cholera, Dengue fever, Rift Valley fever (RVF) and chikungunya.

According to Unicef, heavy rains have affected more than 547,000 people in Somalia and displaced 370,000 people. Uganda has also been affected while in Tanzania the death toll from floods has risen to more than 40 people. In Kenya, more than 100,000 people are affected, with Wajir county among those hardest-hit.

An aerial view taken from a helicopter shows flooding in Lukuangole, South Sudan Nov 1, 2019. REUTERS/Samir Bol

A child displaced by flood sits on a wheelbarrow in Gumuruk, South Sudan Nov 1, 2019. REUTERS/Samir Bol

Children displaced by floods clean their laundry within the flood waters, South Sudan Nov 1, 2019. REUTERS/Samir Bol

An aerial view taken from a helicopter shows flooding in Lukuangole, South Sudan Nov 1, 2019. REUTERS/Samir Bol

A child displaced by flood sits on a wheelbarrow in Gumuruk, South Sudan Nov 1, 2019. REUTERS/Samir Bol

Children displaced by floods clean their laundry within the flood waters, South Sudan Nov 1, 2019. REUTERS/Samir Bol

An aerial view taken from a helicopter shows flooding in Lukuangole, South Sudan Nov 1, 2019. REUTERS/Samir Bol

Children displaced by floods clean their laundry within the flood waters, South Sudan Nov 1, 2019. REUTERS/Samir Bol

An aerial view taken from a helicopter shows flooding in Lukuangole, South Sudan Nov 1, 2019. REUTERS/Samir Bol

Children displaced by floods clean their laundry within the flood waters, South Sudan Nov 1, 2019. REUTERS/Samir Bol