Earth’s oceans are simmering with the heat trapped by increasing amounts of greenhouse gases. But one patch of water in the North Atlantic is stubbornly resisting the trend, and actually dropping in temperature.

This ‘cold blob‘ has been a subject of interest for climatologists ever since it was first spotted back in 2015. Unfortunately, the complexities of ocean circulation make it a tricky thing to easily explain.

A new study adds detail to the phenomenon, revealing there’s more than one cause at work.

A team of researchers from the Max Planck Institute for Meteorology in Germany applied long-term climate modelling to simulate various configurations to find which match the observed plunge in temperature.

One of the factors they identified comes as no real surprise, backing up previous studies that show a current of water called…