By Sam Collentine, Meteorologist Posted 4 years ago November 5, 2019
The Pacific Ocean "Blob" - Explained
In the fall of 2014, Nick Bond, a research scientist at JISAO and Washington State Climatologist, coined a patch of unusually warm water off the North American coast "the Blob". The warmer temperatures went on to wreak havoc on marine environments over the following year. Now, in late 2019, another slug of warm water has appeared, this time stretching all the way to Hawaii.
According to Bond, the Blob is likely a result of an extended ridge of high pressure that sits directly off and over the West Coast of the United States. This high pressure stretches north to the Bering Sea and Alaska, which according to daily monitoring from NOAA, includes unusually warm temperatures in recent years
The University of Washington's College of the Environment recently sat down with Bond to talk about this new Blob, what we might expect, and its impact on the marine ecosystem.
We’re seeing a new Blob form along our coast. How does it compare to the one in 2014?
At its maximum right now, well off the coast of Oregon, it’s about three degrees Celsius (five degrees Fahrenheit) above normal. It’s very warm in the Gulf of Alaska, and the Chukchi Sea is really hot. The present event is at least as big as it was in 2014. It doesn’t extend as far down into Southern and Baja, California like the last one, but it does extend a little bit further out to the southwest. For most of its geographic extent, it looks like the layer of warm water is relatively shallow, roughly 20-30 meters deep, whereas with the Blob of 2014-16 was more like 100 or more meters deeper.
We know that the last one had profound impacts on the marine ecosystem. Can you talk about those impacts?
We noticed the warmer water in the summer of 2014, but it really started manifesting in real noticeable impacts later in 2014 as that warm water moved into the coastal region. One of the first real effects we saw was a massive die-off of seabirds along the Washington-Oregon coast, Cassin’s auklets. They were emaciated. The auklets target krill and large zooplankton that depends on cold water. Then in 2015, all sorts of things happened. Higher mortality of marine mammals, from sea lions down in California to fin whales in the Gulf of Alaska. There were also harmful algal blooms that got a lot of attention. Soon there were a lot of unusual sightings of warm water species, including things like ocean sunfish that were up in the Gulf of Alaska. So there were all sorts of disruptions to the marine environment.
What about now? Are we seeing these same disruptions to marine organisms?
It’s a little early. We don’t really know how this one is going to play out.
How long can we expect this current Blob to stick around?
The seasonal weather predictions are suggesting that as the storms start rolling through the north Pacific, the warm water temperatures will get damped down. In most cases, as storm systems go by there’s an increase of winds that draws more heat out of the ocean. Moreover, the winds and associated waves with those storms cause more mixing of the upper ocean, bringing up cooler water from below which cools the surface layers. We think for this year it’ll stay on the warm side, but not as warm as it was with this past event.
Why are we seeing this happen, and is this something that we can expect more of?
The climate community is looking into that. The easy answer is that it is random variability in the atmosphere and ocean. It’s not like we’ve gone into a different sort of climate regime where the weather patterns have really shifted or anything like that. But we also know that the oceans are warming; there’s a baseline upward trend in temperatures. So that means when we get these perturbations, they’re happening on top of what’s already an elevated baseline. I think the important point is that with climate change, at least so far, it’s just making it that much worse.
What can we learn about the future from these events?
From the ecosystem point of view, we can use these events to a certain extent as a dress rehearsal for the kind of changes we’re anticipating with global warming. In very rough terms, the climate models as a group are showing that the temperatures in these warm events are going to be what the normal temperatures are in the middle of the century. We’re certainly going to have warm and cool events in the future, so with that baseline warming, it means that when you have those warm events in the future, they’re going to be out there in uncharted territory. And then it’ll take a cool event in the future to create something like what we see as normal conditions today.
Final Question: If you had to rename "the Blob", what would you name it?
Yeah, well, you know, I have some regrets about coming up with that four-letter word, you know, digging deep into my vocabulary, of course. Yeah, boy. I think the term "marine heatwave" is better. Maybe it doesn’t roll off the tongue quite the same way, but I’m comfortable with that.
This interview originally appeared in the November 2019 University of Washington College Newsletter.
In summary, "the Blob" is potentially harmful to marine life, but it is a result rather than a cause of weather. We should not blame the Blob for the lack of snow and dry weather that has been observed in California and across the Western United States.
NOAA: The tropics as a prime suspect behind the warm-cold split over North America during recent winters. Link to read here.
Cliff Mass: Why have our low temperatures been so HIGH this summer? Link to read here.
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