WASHINGTON, D.C. – The one common element in recent weather has been oddness. The West Coast has been warm and parched; the East Coast has been cold and snowed under. Fish are swimming into new waters and hungry seals are washing up on California beaches.
A long-lived patch of warm water off the West Coast, about 1 to 4 degrees Celsius (2 to 7 degrees Fahrenheit) above normal, is part of what’s wreaking much of this mayhem, according to two recent papers in Geophysical Research Letters, a journal of the American Geophysical Union.
“In the fall of 2013 and early 2014 we started to notice a big, almost circular mass of water that just didn’t cool off as much as it usually did, so by spring of 2014 it was warmer than we had ever seen it for that time of year,” said Nick Bond, a climate scientist at the University of Washington-based Joint Institute for the Study of the Atmosphere and Ocean, and lead author of one of the new studies.
Bond coined the term “the blob” last June in his monthly newsletter as Washington’s state climatologist. He said the huge patch of water – 1,000 miles (1,609 kilometers) in each direction and 300 feet (91 meters) deep – had contributed to Washington’s mild 2014 winter and might signal a warmer summer.
Ten months later, the blob is still off our shores, now squished up against the coast and extending about 1,000 miles (1,609 kilometers) offshore from Mexico up through Alaska, with water about 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than normal. Bond says all the models point to it continuing through the end of this year.
The new study by Bond and his colleagues explores the blob’s origins. It finds that it relates to a persistent high-pressure ridge that caused a calmer ocean during the past two winters, so less heat was lost to cold air above. The warmer temperatures we see now aren’t due to more heating, but less winter cooling.
The authors look at how the blob is affecting West Coast marine life. They find fish sightings in unusual places, supporting recent reports that West Coast marine ecosystems are suffering and the food web is being disrupted by warm, less nutrient-rich Pacific Ocean water.
The blob’s influence also extends inland. As air passes over warmer water and reaches the coast it brings more heat and less snow, which the paper shows helped cause current drought conditions in California, Oregon and Washington.
The blob is just one element of a broader pattern in the Pacific Ocean whose influence reaches much further – possibly to include two bone-chilling winters in the Eastern U.S.