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 University of Washington papers to appear 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 UW-based Joint Institute for the Study of the Atmosphere and Ocean, a joint research center of the UW and the U.S. National Oceanic and Atmospheric Administration.
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 in each direction and 300 feet 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 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 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.