El Niño ebbs after summer of despair
Mbongeni Mguni | Monday April 8, 2024 06:01
The phenomenon shift comes not a moment too soon after an update made available this week shows over 9,000 drought-related reported cattle deaths in Botswana, Namibia, Zambia, and Zimbabwe between October 2023 and February 2024.
“A record mid-season dry spell of over 30 days has affected vast parts of the region including Angola, Botswana, DRC, Malawi, Mozambique, Namibia, Zambia, and Zimbabwe,” SADC researchers stated. “These areas have received the lowest rainfall for the late-January/February timeframe in at least 40 years.”
Charles Molongwane, principal meteorologist at the Department of Meteorological Services, says a change is coming.
“We are going to be transiting into ENSO neutral in the next few months,” he told Mmegi recently.
But what are El Niño and ENSO neutral?
According to the US National Ocean Service and the United Nations Office for the Coordination of Humanitarian Affairs, El Niño means Little Boy in Spanish. South American fishermen first noticed periods of unusually warm water in the Pacific Ocean in the 1600s. The full name used is El Niño de Navidad because El Niño typically peaks around December.
“In Southern Africa, the El Niño weather phenomenon is a significant factor driving humanitarian needs. Its effects, including drought, erratic rainfall, flooding, and high temperatures, vary across different areas within countries,” researchers from both organisations state.
The region is experiencing extremely dry conditions during the 2023–2024 El Niño season, including one of the driest Februarys experienced in over 40 years, resulting in widespread crop failure across central parts of the region. These conditions have also led to water scarcity, diminished crop yields, and subsequently, food shortages, along with displacement and the proliferation of diseases.
ENSO neutral or the El Niño-Southern Oscillation (ENSO) in a neutral phase, occurs when water temperature anomalies in the eastern and central Pacific are between 0.5°C and -0.5°C.
This transition will hit Botswana over the winter to spring period when the country generally does not receive rains and when most subsistence farmers are off their fields.
Critical to the turnaround in rainfall fortunes, many in the country hope to see ENSO neutral in the return of summer later this year.
According to the National Oceanic and Atmospheric Administration, the US government agency charged with forecasting weather as well as monitoring oceanic and atmospheric conditions, climate changes are likely to shift to ENSO neutral from April to June with odds of La Niña developing between June and August, rising to 55%.
For Botswana and neighbouring countries, La Niña conditions point to higher rainfall amounts, more widely spread across the summer season. La Niña can be remembered in 2019 when Gaborone recorded 244 millimetres of rain in the space of a few weeks between November and December, then the wettest start to the rain season in decades.
Farmers and ordinary Batswana will be hoping the forecasts come to fruition this year, following a season to forget.