On Dec 29, 4:18 pm, Robbo <[email protected]> wrote: > Tsonis et al (2007) and Swanson and Tsonis (2009) results are not > based on correlation. They used a relatively new network approach to > analysing complex systems. They used 4 ocean/climate indices - the > Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation > (NAO), the El Nin˜o/Southern Oscillation(ENSO), and the North Pacific > Oscillation (NPO) and show that climate behaves on multidecadal > timeframes as you would expect it to - as a complex system in terms of > complex systems theory. Climate bahaves as a forced nonlinear > oscillator at scales frome ENSO to ice ages and beyond. This supports > your argument rather than otherwise. Small changes in initial > conditions leading to large changes in climate. > > See for instnce - Slowing down as an early warning signal for abrupt > climate change - Vasilis Dakos*, Marten Scheffer*†, Egbert H. van > Nes*, Victor Brovkin‡§, Vladimir Petoukhov‡, and Hermann > Held‡:www.pnas.org/cgi/doi/10.1073/pnas.0802430105 > > The 2007 paper from Tsonis et al- A new dynamical mechanism for major > climate shifts - is the more important in giving the background ideas. > The 2009 Swanson and Tsonis paper is an update. There is no such thing > as simple causality in climate - climate has many degrees of freedom > that are dynamically interactive. There is no chicken and no egg - > just a dynamically evolving system that includes both the PDO and THC > as well as many other factors.
The system is highly damped, else the entire climate system would "ring" with a harmonic of the major driving force, the yearly insolation cycle, would it not? Remember that the forces must balance the energy flows thru the system, sunlight in, IR out and the IR emissions are a function of T^4 (mol). That there is an obvious oscillation in the ENSO cycle does not imply that there are other, longer term periods of oscillation (not fixed period cycles). It's often claimed that the solar sunspot cycle shows up in the weather data, but finding the longer term frequencies, such as the Gleissberg cycle, is a subject of continual debate. > The 10,000 years was eyeballed from the Vostok ice core data. Temp > changes either way of up to 10 degrees over a few thousand years. The > Bermuda-Labrador Basin Transport Index is down since early this > century - there is a nice collection of ocean/climate data > athttp://ioc-goos-oopc.org/state_of_the_ocean/sub/berm_lab_trans.php- > and it is très amusant to speculate that early in 1998 might have been > the warmest point in the next 100,000 years. It is overwhelmingly > probable that an ice age is around the next climate > corner. > > That gives me an idea - use autocorrelation minima (slowing down in > complex systems theory) on the Vostok data to predict initiation of > the next ice age. I may be gone for some time. Before you go off on a wild goose chase, here's some food for thought: http://www.aip.org/history/climate/cycles.htm E. S. --- -- You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/globalchange
