Pacific Ocean 'Blob' blamed for making summer air quality worse in 2015

SEATTLE -- It's not enough "The Blob" had to take away a winter's snowpack and help make for some of the hottest summers on record in the Pacific Northwest two years ago, now it's also being blamed for making air quality worse.

New research by meteorologists at the University of Washington-Bothell found higher concentrations of ozone across much of the West Coast in the summer of 2015, especially the Northwest.

"The Blob" was the colloquial name regionally adopted to describe an unusual pool of warm waters that formed in the Pacific Ocean just off the U.S. West Coast. With water temperatures reaching as much as 5-7 degrees above normal, "the Blob" acted like a massive electric blanket, helping Seattle's winter of 2014-15 be relatively chill-free and shattering records for hottest summer --and hottest year on record. The city had a record-smashing 12 days above 90 degrees in 2015 and eight of the year's months finished in the Top 5 warmest on record, with four setting all-time highs.

Those hot temperatures and corresponding lack of cloud cover and calmer winds were the perfect conditions to produce ozone, which is a result of chemical reactions between solar energy and pollution and is considered hazardous to human health.

And produce ozone it did. Elevated ozone levels were found in Washington, Oregon, western Utah and northern California, according to the UW study published Wednesday in Geophysical Research Letters as part of the American Geophysical Union.

Lead author Dan Jaffe ,a professor of atmospheric sciences at the University of Washington-Bothell, says the effects were most noticeable in our neck of the woods.

"Washington and Oregon was really the bullseye for the whole thing, because of the location of the winds," Jaffe said in a UW news release announcing the study's results.

Jaffe's group has been measuring ozone since 2004 from high atop Mt. Bachelor in central Oregon. They noted a large spike in the measurements taken in June of 2015 -- an increase of 12 parts per billion above the average.

"At first we were like 'Whoa, maybe we made a mistake,' " Jaffe said. "We looked at our sensors to see if we made an error in the calibration. But we couldn't find any mistakes. Then I looked at other ozone data from around the Pacific Northwest, and everybody was high that year."

Indeed, ozone levels were found to have been between 3 and 13 parts per billion higher than average over the northwestern U.S. and the increase was enough to push Salt Lake City and Sacramento over the federally allowed limits of 70 ppb, the study said.

"Managers saw that air quality was violating the air quality standards on many days, and they didn't know why," Jaffe said.

Jaffe and his team's analysis concluded the higher ozone spikes corresponded to areas under the spell of "The Blob's" effects.

"Ultimately, it all links back to the blob, which was the most unusual meteorological event we've had in decades," Jaffe said. "Temperatures were high, and it was much less cloudy than normal, both of which trigger ozone production. And because of that high-pressure system off the coast, the winds were much lower than normal. Winds blow pollution away, but when they don't blow, you get stagnation and the pollution is higher."

Jaffe says his research suggests large scale climate patterns also play roles in air quality.

"Our environmental laws need to be written with an understanding that there's a lot of variability from one year to the next, and with an understanding of the long-term path of where we're heading under climate change," Jaffe said. "This work helps us understand the link between climate variability and air quality, and it can give us an idea of what to expect as our planet continues to warm."

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