A significant portion of the Atlantic Ocean near the equator experienced a rapid and unprecedented cooling over the summer months, leaving scientists puzzled about the cause. While the temperatures in the area have started to climb back to normal levels, the reasons behind this sudden drop remain unclear. The cold patch, which appeared in early June, formed after months of unusually warm surface waters. Scientists are now attempting to unravel the mystery, but so far, have found few explanations.
Unusual Temperature Drop
The affected area spans several degrees both north and south of the equator and is known to fluctuate between warm and cold phases every few years. However, the rate of cooling observed this time was exceptional. Franz Tuchen, a postdoctoral research associate at the University of Miami, is closely monitoring this event and acknowledges that the rapid temperature decline is highly unusual, he highlighted in a blog post.
Similarly, Michael McPhaden, a senior scientist with the National Oceanic and Atmospheric Administration (NOAA), has expressed his confusion, noting that the phenomenon could be the result of processes that are not yet fully understood.
Potential Links to Climate Patterns
In February and March, the sea surface temperatures in the eastern equatorial Atlantic reached their highest levels since 1982, exceeding 30 degrees Celsius. By June, temperatures began to plummet, reaching their lowest point at 25 degrees Celsius by late July.
Initial forecasts suggested that this cooling event might evolve into an Atlantic Niña, a regional climate pattern that typically increases rainfall in western Africa and decreases it in northeastern Brazil and other regions near the Gulf of Guinea. However, as the cold patch has recently begun to warm, it is now unlikely to be classified as an Atlantic Niña.
Possible Causes Being Investigated
Despite the current warming trend, understanding the factors that led to the dramatic cooling is essential for better grasping Earth’s climate dynamics, which could ultimately improve weather forecasting. However, none of the expected processes, such as stronger trade winds or equatorial upwelling, appear to be responsible. In fact, the cooling region coincided with weaker winds southeast of the equator, contradicting the typical pattern where stronger winds would lead to cooler surface waters.
McPhaden pointed out that while some unusually strong winds developed to the west of the cold patch in May, they were not strong enough to account for the significant temperature drop. As a result, scientists have been exploring other potential climate processes, such as heat fluxes in the atmosphere or shifts in ocean and wind currents, but none have emerged as clear drivers of the event.
Ongoing Research and Observations
Although the dramatic cooling is not believed to be directly linked to human-driven climate change, it remains a natural variation of the climate system in the equatorial Atlantic. Tuchen, McPhaden, and other climate scientists are continuing to monitor the cold patch using data from satellites, oceanic buoys, and other meteorological tools. The full impact of this event on surrounding regions may take months to unfold, but scientists are keeping a close watch on any developments.