April 9, 2015
‘Warm blob’ in Pacific Ocean linked to weird weather across the U.S.
‘Warm blob’ in Pacific Ocean linked to weird weather across the U.S.
In a blog post last month, Hartmann focused on the more recent winter of 2014-15 and argues that, once again, the root cause was surface temperatures in the tropical Pacific.
That pattern, which also causes the blob, seems to have become stronger since about 1980 and lately has elbowed out the Pacific Decadal Oscillation to become second only to El Niño in its influence on global weather patterns.
“It’s an interesting question if that’s just natural variability happening or if there’s something changing about how the Pacific Ocean decadal variability behaves,” Hartmann said. “I don’t think we know the answer. Maybe it will go away quickly and we won’t talk about it anymore, but if it persists for a third year, then we’ll know something really unusual is going on.”