Amaya, D. J., N. E. Bond, A. J. Miller and M. J. DeFlorio, 2016:
The evolution and known atmospheric
forcing mechanisms behind the 2013-2015
North Pacific warm anomalies
U.S. CLIVAR Variations, 14, 1-6.
Summary.
In the winter of 2013/2014, North Pacific sea surface
temperature (SST) anomalies exceeded three standard deviations above the mean
over a large region, shifting focus away from the tropics and onto the extratropics
as the associated atmospheric circulation patterns helped exacerbate the most
significant California drought in the instrumental record.
This extratropical warming has since become known in the
media and the literature simply as "the Blob" or "the Warm Blob" and represents a
climate state unlike anything seen in the last 30 years.
In contrast to the more offshore Blob, the Arc Pattern that followed it in fall 2014 is
characterized by broad coastal warming, reminiscent of
a Pacific Decadal Oscillation (PDO)-like structure.
The Baja Warming Pattern, the third and final development of these extreme anomalies in fall 2015, has similar spatial
characteristics to the Pacific Merdional
Mode.
We present here a synthesis of what
is currently known about the occurrence and unique forcing mechanisms of these extreme warm SST anomalies (marine heat waves), including comparisions with historical magnitudes.
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