Two years ago, a huge, inexplicable hot patch of water appeared in the Pacific Ocean, and stayed right through the seasons — until now. Referred to among scientists as "the Blob", it's finally gone away, taken by El Niño. It may only be a matter of time, though, before the Blob lives again. Image: A comparison of Pacific sea surface anomalies at the end of July 2015 and the beginning of January 2016 / Images from NASA Earth Observatory
When the Blob appeared in the Pacific sometime around the end of 2013, scientists thought it was just a temporary anomaly in hot ocean temperatures. When it hadn't disappeared after two years, however, the question instead became whether or not it was going away at all. With the latest data, NASA's Earth Observatory is finally calling the Blob dead.
The hot, still water in the Blob was so churned up by the combination of El Niño winds and low sea surface pressures that, although there were some initial fears that warm El Niño temperatures might make things even hotter, instead the opposite happened. This El Niño is probably the strongest one ever seen. Even with all that strength, though, the Blob was so resilient to change that, even though El Niño started to work on it in November, it took months for it to finally break itself apart.
The disappearance of the Blob is good news, especially for fishers. While it was there, the Blob's warm water killed off marine life and fed a toxic algae bloom. What it's not, though, is anything even approaching an answer to just what all of that was — or what it might be in the coming years.
Researchers still aren't really sure where the Blob came from the first time, and so they're also not sure whether El Niño's dissipation of that hot water is permanent or temporary. What they are sure of, though, is that — even after El Niño broke things up — the residual heat of the Blob was so intense that pockets of warm water still remain as deep as 300m below the surface to this day. At least for now, though, the larger Blob seems to have left as mysteriously as it came.
Top image: The Pacific sea surface in July 2015 / Image from NASA Earth Observatory