La Nina is a weather phenomenon that occurs in the Pacific Ocean but can have a series of effects on weather patterns around the world. This year, the La Nina process in the tropical Pacific Ocean has not gone smoothly.
The slow emergence of La Nina shows some of the effects of long-term human-caused global warming. La Nina and El Nino are the main causes of climate change around the world in the short to medium time range.
The arrival of La Nina, far from the initial forecast this year, is forcing climate scientists and meteorologists to rethink some of the long-standing methods used to measure and predict these events.
Currently, the La Nina signal in the equatorial tropical Pacific Ocean has not yet appeared due to the influence of record-warm ocean temperatures outside the region, Axios informed.
This means that the framework that meteorologists use to diagnose, detect and describe La Nina may need to be updated. Researchers have been researching this issue and are likely to have a solution.
Axios explains that this is related to climate change that is turning off signals of La Nina and El Nino events by increasing ocean temperatures over large seas and potentially changing the weather patterns that La Nina often affects.
With global sea surface temperatures reaching record highs in 2023 and 2024, the way scientists calculate the presence of La Nina is being broken. Currently, although the sea water temperature has decreased, it is still much higher than normal.
According to ENSO forecaster Michele L'Heureux of the National Oceanic and Atmospheric Administration (NOAA)'s Climate Prediction Center, comparing ocean temperatures to the 30-year average may no longer be effective because rapid warming is occurring.
Instead, the relatively large ENSO index could be a better diagnostic tool, she said. This index compares ocean temperatures in the relevant tropical equatorial Pacific Ocean with the surrounding oceans to diagnose the occurrence or presence of La Nina.
Ms. L'Heureux has published studies on the " relatively ENSO index" and NOAA scientists are discussing with forecasters at many other agencies, including the Australian Bureau of Meteorology, to determine the right time to use this index.
Winter is usually the time when the La Nina effect is most obvious, but it is predicted that this La Nina will appear weak and short. An important question for forecasters is whether typical La Nina weather patterns will emerge this winter based on forecast intensity. Ms. L'Heureux pointed out that a weak La Nina does not mean having small impacts on the weather.
