August 15, 2007
LOOKS LIKE CAPTAIN OZONE WILL HAVE TO KILL EL NINO:
Synchronized Chaos: Mechanisms For Major Climate Shifts (American Geophysical Union, 8/02/07)
In the mid-1970s, a climate shift cooled sea surface temperatures in the central Pacific Ocean and warmed the coast of western North America, bringing long-range changes to the northern hemisphere.Posted by Orrin Judd at August 15, 2007 12:51 PMAfter this climate shift waned, an era of frequent El Ninos and rising global temperatures began.
Understanding the mechanisms driving such climate variability is difficult because unraveling causal connections that lead to chaotic climate behavior is complicated.
To simplify this, Tsonis et al. investigate the collective behavior of known climate cycles such as the Pacific Decadal Oscillation, the North Atlantic Oscillation, the El Nino/Southern Oscillation, and the North Pacific Oscillation.
By studying the last 100 years of these cycles' patterns, they find that the systems synchronized several times.
Further, in cases where the synchronous state was followed by an increase in the coupling strength among the cycles, the synchronous state was destroyed. Then. a new climate state emerged, associated with global temperature changes and El Nino/Southern Oscillation variability.
The authors show that this mechanism explains all global temperature tendency changes and El Nino variability in the 20th century.
"After this climate shift waned, an era of frequent El Ninos and rising global temperatures began."
I don't know whether to blame the scientists or the media, but there's been a strange shift in the apparent definition of "El Nino" in the past 20 years or so. It was originally supposed to refer to the large warm ocean currents in the equatorial Pacific off of South America that produced unusually severe weather (such as very, very wet winters in the Western US, and very hot summers), every 7 years or so (2004, 1998, 1992, 1983). In recent years there have apparently been "El Nino" events (defined as the presence of that warm ocean current) every couple of years, and yet the severe weather years (which used to be the defining characteristic of "El Nino") still occur every 7 years. In other words, someone (and, again, I'll let the reader decide whether it's likely the scientists or the media) doesn't know what the heck they're talking about.
Posted by: b at August 15, 2007 1:47 PMBut the "Science is settled" and that's that. End of discussion! The world's scientists are in consensus.
Posted by: Genecis at August 16, 2007 7:46 AM