Atlantic ocean's mysterious cooling baffles scientists

A large area of the Atlantic Ocean near the equator is cooling down. Scientists do not know what is causing this phenomenon, and little information has been available to help decipher the mystery.

This summer, over the span of a few months, a wide band of the Atlantic Ocean along the equator cooled down at a record pace. The "cold patch" is slowly fading, but scientists still do not understand what is causing the change in water temperature.

As reported by livescience.com, the cold patch anomaly formed at the beginning of June following a series of the highest surface water temperatures observed in over 40 years. Although it is known that this region transitions from a warm phase to a cold phase every few years, the speed at which it went from record high to low temperatures is "truly unprecedented," according to Franz Tuchen, an associate professor at the University of Miami.

"We are still scratching our heads over what exactly is happening," said Michael McPhaden, a senior scientist at the National Oceanic and Atmospheric Administration (NOAA) in an interview with Live Science. "It may be some transient feature that developed from processes we don't fully understand," he added.

Surface water temperatures in February and March exceeded 30 degrees Celsius, making them the warmest since 1982. Starting in June, temperatures began to plummet, reaching about 25 degrees Celsius.

Forecasts indicate that the cooling may be on the brink of transforming into the Atlantic version of Niña. This climate pattern tends to increase rainfall in western Africa and decrease it in northeastern Brazil and countries around the Gulf of Guinea. This phenomenon is not as strong as La Niña in the Pacific and has not occurred since 2013. It would be declared if below-average temperatures persisted for three months, i.e., until the end of August. In recent weeks, water temperatures have slightly increased.

However, Franz Tuchen argues that determining exactly what caused the dramatic cooling would allow scientists to better understand the whims of Earth's climate, which could benefit weather forecasting.

According to scientists, water temperature cooling is also associated with trade winds blowing near the equator. McPhaden suggests that some abnormally strong winds, which developed west of the cold patch in May, might have initiated the record-fast cooling. However, the wind strength did not increase as much as the temperature dropped.

Scientists believe that the recent changes in water temperature are unlikely related to human activity. McPhaden argues that it cannot be ruled out, but he believes it is a natural process.