Saturday, October 4, 2014

New excuse #53 for the "pause" in global warming: "Competition" with two natural ocean oscillations

A new paper published in the Journal of Geophysical Research Atmospheres finds the "recent cooling in the eastern Pacific Ocean and associated climate impacts" are due to "a competition of global warming" with the natural ocean oscillations the "Interdecadal Pacific Oscillation (IPO), and the Atlantic Multidecadal Oscillation (AMO)." 

The authors relate the eastern Pacific cooling over the past 29 years to a "competition" between "global warming" & IPO & AMO, and to the "climate impacts" which have in-turn been linked to the 18+ year "pause" of global warming. 

According to the authors,
"The cooling trend in the eastern tropical Pacific sea surface temperature (SST) during 1979-2008 is statistically significant at the 10% level out of the equator rather than along the equator."
The paper is a new variant on others claiming the negative phase of the Interdecadal Pacific Oscillation (IPO) was alone responsible for the 18-26 year "pause" in global warming, others claiming some combination of the Atlantic Multidecadal Variability and Pacific Decadal Oscillation (PDO) were jointly responsible, as well as others claiming 'missing heat' in the deep Atlantic alone was responsible.


The formation of the recent cooling in the eastern tropical Pacific Ocean and the associated climate impacts: A competition of global warming, IPO and AMO

Lu Dong and Tianjun Zhou

The cooling trend in the eastern tropical Pacific sea surface temperature (SST) during 1979-2008 is examined by using a wide variety of datasets for the ocean and atmosphere. The results show that the cooling trend is statistically significant at the 10% level out of the equator rather than along the equator. Diagnostic analysis indicates that the SST cooling in the eastern tropical Pacific is resulted from a competition of global warming mode, Interdecadal Pacific Oscillation (IPO) mode and Atlantic Multidecadal Oscillation (AMO) mode. The cooling trend is preliminarily dominated by the phase transition of IPO from positive to negative phases in the year around 1998/1999, which overwhelms the effect of global warming in past three decades. Quantitative estimates based on the average of four different SST datasets indicate that the global warming mode offsets more than half of the cooling effect of IPO mode. The phase transition of AMO during 1990s causes a weak warming trend in the eastern tropical Pacific and partly weakens the cooling, making the trend along the equator less significant. Climate impacts associated with global warming mode, IPO mode and AMO mode are further examined. The surface air temperature cooling over the eastern tropical Pacific, the easterly wind anomaly along the Pacific equator, the enhanced zonal gradient in sea level pressure over tropical Pacific, and the increased precipitation over the Asian monsoon region during 1979-2008 are dominated by the phase transition of IPO.


It's not nice to fool Mother Nature
Or to "compete" with her either

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