oceans experience nearly two months of record temperatures; Find out what is known about the phenomenon | environment

The world’s oceans a temperature record of surface waters since March. The latest measurements reached a temperature of 21 degrees Celsius, which is a figure – at least – 0.2 degrees Celsius higher than that achieved in previous periods.

Since March 13, the average global ocean temperature has exceeded the values ​​of all annual measurements since the 1980s.

📈 context: On April 24, the global average sea surface temperature exceeded approx One-tenth of a degree Celsius (0.2°C) compared to the same date in 2016 (the hottest year so far).

The data is from the University of Maine Climate Analyzer, which is a climate and meteorological data platform widely used by researchers in the field. (See chart below).

This may seem like a minuscule amount, but for the average world’s oceans – which occupy 71% of the Earth’s surface – to increase by that amount in such a short time “is huge”, explains climate scientist Chris Karnauskas, of the University of Colorado in the US.

🌡 Possible hypotheses for the record: Some researchers believe that this jump in ocean temperatures is related to the following factors:

🌊 First of all, we need to understand that the El Niño is caused by a slowdown in the trade winds, which blows in a westerly direction near the equator. Where there is nothing to transfer heat towards the Indian Ocean, the Pacific waters cook in the sun, without moving much, and end up much warmer.

With that said, the northern and northeastern regions here in Brazil, for example, tend to get less rain during an El Niño event, while it rains more frequently in the south.

Another feature of the phenomenon in the country is the high temperatures in winter in the southeast and in the second half of the year in the midwest.

The World Meteorological Organization (WMO) estimates that there is a 60% chance of an El Niño by the end of July.

Therefore, some climatologists dismiss concerns surrounding this sudden increase and claim that it is the result of a higher El Niño accompanied by a steady increase in human-caused warming.

➡️ An important factor for this thesis is that this warming of the oceans was seen in particular off the coasts of Peru and Ecuador, where most of the El Niño events began prior to the 1980s.

On the other hand, other researchers say this does not seem to be just a consequence of El Niño. This is because there are many marine heat waves or points of ocean warming that do not fit the pattern of the phenomenon, such as those in the North Pacific Ocean near Alaska and the coast of Spain.

“That’s a big sign. I think it’s going to take us some effort to really understand it.”

Karnauskas also analyzed some of the global sea surface temperature anomalies in an effort to understand which regions were responsible for much of the global warming.

In doing so, he found a long stretch of the equator from South America to Africa, which included the Pacific and Indian oceans.

In March, sea surface temperatures off the east coast of North America were 13.8°C higher than the 30-year average from 1981-2011.

For Karnauskas, part of this region is clearly an El Niño phenomenon in the making, a thesis that scientists could confirm in the coming months as the phenomenon gains strength. But the region in the Indian Ocean is different and may be an independent increase in this phenomenon.

In addition to this warming, the world experienced an unusually cool surface due to La Niña for three years, a phenomenon that was a veritable cap on a bowl. But now that lid is closed.

Without La Niña, the level of warming would have been worse. “It has been a temporary drawback to rising global temperatures,” said Petteri Taalas, WMO Secretary-General.

However, the effect of El Niño on temperatures is usually observed in the year following the meteorological phenomenon. Therefore, the WMO fears that the effects may be observed in 2024.

In addition, the problem is that the temporary La Niña control over the increase in global temperatures no longer exists. “One consequence of this is that March 2023 was the second-highest March on record in terms of global mean surface temperatures on the planet,” NOAA oceanographer Mike McFadden said in an email.