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The the World Meteorological Organization (WMO) have warned that the La Nina that took has caught the Earth since September 2020 is set to last 2023.
The La Nina has affected global temperatures and worsened droughts, flooding, temperatures and rainfall patterns. The UN agency also stated that if the climatic effect sustains till 2023, this will be "triple-dip La Niña" the third such instance since 1950 that La Nina has stayed on for three years.
WMO Global Producing Centers for Long Range Forecasts indicate that there is about a 70% chance of the current La Niña conditions extending into boreal summer 2022, and about 50-60% during July-September 2022. “Despite the stubborn La Niña in the equatorial central and eastern Pacific, widespread warmer than-average sea-surface temperatures elsewhere are predicted to dominate the forecast of air temperatures for June-August 2022. However, the extent and strength of predicted warming is less than during March-May 2022... ," WMO said.
There are some indications that the probability may increase again slightly during the boreal fall of 2022 and early boreal winter of 2022-23.
What is La Nina
La Niña refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation, namely winds, pressure and rainfall. It usually has the opposite impacts on weather and climate as El Niño, which is the warm phase of the so-called El Niño Southern Oscillation (ENSO).
La Nina effect
The WMO said that there is a good 70% chance that that the protracted La Nina event -- which has held the globe in its clutches almost uninterrupted since September 2020 -- will continue until at least August.
"Some long-lead predictions even suggest that it might persist into 2023," it said in a statement.
The effect has widespread impacts on weather around the world -- typically the opposite impacts to the El Nino phenomenon, which has a warming influence on global temperatures.
Notably, the current la Nina took effect in Septemver 2020 and has continued through May 2022 across the tropical Pacific.
There was a temporary weakening of the oceanic components of La Niña during January and February 2022, but it has strengthened since March 2022.
Example of La Nina
The weather conditions in La Nina are empirically favourable than the El Nino effect. The ongoing drought situation in the Horn of Africa are the southern part of South America are testimony to the ongoing La Nina effect.
The above average rainfall in South East Asia and Australia and the predictions for an above average Atlantic hurricane season are also hallmarks of hte La Nina effect.
Human impact on climate and La Nina
It has been understood and stressed upon that the global climate change now is a cause of human interruption. the naturally occurring climate events are also intensifying due to the rising temperatures on earth or global warming.
"Human-induced climate change amplifies the impacts of naturally-occurring events like La Nina and is increasingly influencing our weather patterns," WMO chief Petteri Taalas said in a statement.
He pointed in particular to "more intense heat and drought and the associated risk of wildfires -- as well as record-breaking deluges of rainfall and flooding".
La Nina in India
The Indian metrological Department (IMD) has suggested that moderate moderate La Nina conditions are prevailing over the equatorial Pacific region. La Niña conditions are likely to continue throughout the forecast period till September.
In May, IMD said monsoon rainfall between June to September is likely to be “normal" at 103%, with a model error of +/-4%. in April, IMD said monsoon rainfall was likely to be 99% of LPA.
IMD director general M Mohapatra said last month that they have increased the quantum of rainfall likely during monsoon because projections are showing La Nina conditions will continue till the end of monsoon. “La Nina conditions will support normal rains which may be countered a little due to development of negative Indian Ocean Dipole (IOD) conditions over the Indian Ocean."
La Nina has a cooling influence in India even as it recorded a very unusual spring and summer dominated by extreme record-breaking heat spells. Experts said worse is yet to come during the upcoming El Nino season