Extreme heat in the North Pacific: The Blob

Water is strangely warm in parts of the North Pacific: in the Gulf of Alaska, off Southern California, and stretching across the Bering Sea.

A NOAA Northwest Fisheries Science Center press release reported: Not since records began has the region of the North Pacific Ocean been so warm for so long. That references over a century of record-keeping. The sea surface is exhibiting temperatures as much as 3 degrees Celcius [5.4 degrees Fahrenheit] higher than average.

Unusually warm temperatures dominate three areas of the North Pacific: the Bering Sea, Gulf of Alaska and an area off Southern California. Temperature bar lists degrees Celsius (each increment is 1.8 F). / Courtesy NOAA NCDC
Unusually warm temperatures dominate three areas of the North Pacific: the Bering Sea, Gulf of Alaska and an area off Southern California. Temperature bar lists degrees Celsius (each increment is 1.8 F). / Courtesy NOAA NCDC

Nick Bond, climatologist at the Joint Institute for the Study of the Atmosphere and Ocean at University of Washington, reported on the phenomenon in a 2014 Office of the Washington State Climatologist newsletter and dubbed it ‘The Blob’.

Since its seeming origins in the fall of 2013 The Blob has expanded from a circular area off the West Coast to a red (used in images to denote temperatures hotter than usual) coloring waters from the coastline to about 1,000 miles offshore and stretching from Arctic waters off Alaska’s shore along the West Coast down to Mexico. The phenomenon is expected to continue through the end of 2015.

Impacts on wildlife

That’s bad news for established marine food webs. Species thrive best in temperatures they’re adapted to. Even plant species are observed to change ranges in response to heightening temperatures– in North America that means trending north or uphill on mountain slopes. Where they can, marine species might respond to unusual water temperature by changing their ranges. Joseph Orsi, fisheries biologist. Auke Bay Laboratory, Alaska Fisheries Science Center, reported sighting in the Gulf of Alaska of warm water species like ocean sunfish, pomphret, blue sharks and thresher sharks.

Thresher sharks were among the species associated with warmer waters that turned up in research surveys in the Gulf of Alaska this summer / Courtesy NOAA
Thresher sharks were among the species associated with warmer waters that turned up in research surveys in the Gulf of Alaska this summer / Courtesy NOAA

Nate Mantua is an oceanographer. He heads the landscape ecology team at NOAA’s Southwest Fisheries Science Center. According to Mantua “If the warming persists for the whole summer and fall, some of the critters that do well in a colder, more productive ocean could suffer reduced growth, poor reproductive success and population declines,” he said, “This has happened to marine mammals, sea birds and Pacific salmon in the past.” While “At the same time, species that do well in warmer conditions may experience increased growth, survival and abundance.”

Just how will The Blob impact established marine species? Tara Kulash reported in a July 2015 article in the Oregonian titled ‘Sea change: Here’s what’s wrong in the Pacific Ocean’ that native cold-water plankton being impeded or driven away by hot temperatures, or out-competed by tropical plankton, spell bad news for predators that usually prey on them. Cold-water plankton population levels are below normal. Bill Peterson, oceanographer at NOAA’s Northwest Fisheries Science Center, said the tropical plankton moving in with warmer waters aren’t as high in fat content as native cold-water plankton. It means animals like whales and sea birds that feed on plankton have a tougher time.

That could be what’s causing the die-off of seabirds called auklets, which Kulash reported are washing ashore dead on shores from California to Canada. Kulash wrote “That number reached tens of thousands. That’s 100 times more than their average mortality rate.” Peterson said auklets, whose favored plankton prey is cold-water plankton, dive to depths of 40 meters. It’s reasonable to think whatever cold-water plankton remained likely sought refuge below The Blob’s heated water which locally reached something like 80 meters depth.

The Blob’s warm waters boost the growth of toxic algal blooms and spell potential trouble for fisheries. Peterson predicted that migrating juvenile salmon and steelhead reaching the heated ocean waters from the Columbia River may experience poor survival.

“We’re seeing some major environmental shifts taking place that could affect the ecosystem for years to come,” according to John Stein, NOAA Fisheries’ Northwest Fisheries Science Center Director. You can read more from NOAA’s Northwest Fisheries Science Center about ecosystemic impacts in the September 2014 article ‘Unusual North Pacific warmth jostles marine food chain’.

But what is it?

What’s causing the strange warm water zones? The trends don’t match those of El Niño, which promotes unusually warm temperatures in the equatorial Pacific, though El Niño conditions are predicted to be more likely than not to develop this year. They don’t seem to sync perfectly with the Pacific Decadal Oscillation, which is characterized by persistently higher sea surface temperature anomalies in the northeastern Pacific. This is likely something newly recorded and analyzed. A study funded by NOAA titled ‘Causes and impacts of the 2014 warm anomaly in the NE Pacific’ finds The Blob formed because of a persistent high-pressure ridge over the Pacific Ocean.

Storms and winds, when present, stir up waves, assist in heat transfer at the water-air interface, and help drive upwelling of cold water from the deeper ocean. Storm clouds shield ocean waters below from warming sunlight.

High pressure in the atmosphere tends to suppress local winds and storms. So high pressure over the Pacific can reduce heat transference and reduce the formations of storms like the intense winter storms that usually cool off waters in the Gulf of Alaska. The persistent high-pressure ridge reduced winter cooling, which led to The Blob’s unusual endurance.

The persistent ridge of high pressure has affected weather patterns / Courtesy NOAA
The persistent ridge of high pressure has affected weather patterns / Courtesy NOAA

That high-pressure ridge is also being fingered as a culprit encouraging and exacerbating problems on land: the current extreme droughts in the western US, and last winter’s harsh conditions in the eastern US. Bond talks about it more as he revisits the topic of The Blob in a May 2015 article ‘What is the ‘warm blob’ in the Pacific and what can it tell us about our future climate?’ posted on The Conversation.

Climate futures

While The Blob represents an extreme event, Bond recorded “It bears emphasizing that the development and evolution of the blob is an example of a naturally occurring, short-term perturbation in the atmosphere and ocean climate of the North Pacific.” “Nevertheless, the oceans are warming, and conditions akin to those of the last couple of years are liable to become more common in future decades, albeit for different reasons.” This is a chance to look forward.

The US Drought Monitor for July 28 2015 / Courtesy the National Drought Mitigation Center (NDMC) in association with NOAA and the USDA
The US Drought Monitor for July 28 2015 / Courtesy the National Drought Mitigation Center (NDMC) in association with NOAA and the USDA

You can help Oregon State University climate researchers by signing up at climateprediction.net. Researchers are looking for volunteers to lend their computing power to climate models. Essentially the project, promoted by Phil Mote, Director of the Oregon Climate Change Research Institute, creates virtual Earths and simulates different climate environments. If you choose to install it the program will automatically run when your computer is not in use; you can use the program to see the results after a simulation has run on your machine. Pretty cool. Or, visit the website to follow along with the project online.

Laura Nielsen 2015

Frontier Scientists: presenting scientific discovery in the Arctic and beyond