For the third consecutive year, the Australian Bureau of Meteorology has verified the emergence of the La Nina weather pattern in the Pacific, increasing the likelihood of rain and flooding in many regions of the world. La Nia has returned for three consecutive years for the first time in this century, according to the World Meteorological Organization, a UN organisation.
La Nina events occurring three years in a row are unusual, according to WMO Secretary-General Petteri Taalas. One of the three phases of the El Nio Southern Oscillation is the La Nia weather pattern (ENSO). The unexpected cooling of the tropical eastern Pacific is what is being discussed. La Nina, which translates to ‘The Little Girl’ in Spanish, refers to times when the sea surface temperature in the east-central Equatorial Pacific is below normal.
The atmospheric circulation in the tropical Pacific is arranged under this weather pattern such that moisture is pumped into the atmosphere along Australia’s east coast by warm waters to the country’s northeast and strong trade winds. In turn, when the appropriate systems appear, they draw on that moisture, resulting in torrential downpours and flooding. Key atmospheric and oceanic indicators of the El Nio-Southern Oscillation (Enso) revealed ‘an established La Nia,’ according to the bureau’s twice-weekly bulletin on Australia’s climate drivers.
Since June, the Tropical Pacific’s sea surface temperatures have been dropping, and they are already approaching La Nia thresholds, according to the agency. It went on to say that ‘models suggest that this La Nia event may peak around the spring and revert to neutral circumstances early in 2023’.
La Nina’s global repercussions
Winters are often warmer in Northern Europe—especially the UK—and colder in Southern and Western Europe, bringing snow to the Mediterranean area. In Europe, it lessens the frequency of storms in the autumn. The American continent is where the effects of La Nina’s harsh weather are most noticeable. Stronger winds travel along the equatorial area of the Pacific. While it causes favourable storm conditions in the Caribbean and central Atlantic region. Tornadoes occur often in a number of US states.
The National Oceanic and Atmospheric Administration reports that La Nina can increase the frequency of hurricanes and tropical storms in the Gulf of Mexico and along the Gulf Coast, as well as deliver significant rainfall to Australia, Indonesia, and other regions of Asia. In South America, where La Nina produces drought, particularly in Peru and Ecuador, the situation is inverted.
East Africa too has the same challenges. One of the worst droughts East Africa has experienced in decades is presently taking place as a result of the fourth season of failing rains. According to the UN’s World Food Programme, up to 20 million people might be in danger of acute malnutrition in Ethiopia, Kenya, and Somalia, which are on the verge of a historic humanitarian disaster.