Sunday, May 15, 2011

More Analyzing the Wager to Death

The wager based on the 2015 average GISS surface temperature versus the 2008 surface temperature is interesting. The overly simple regression analysis, (or eyeballing) leads me to believe that the wager is pretty fair and is virtually a coin toss. The originator of the wager of course feels that it is a sucker bet, or he would not have made it.

In my opinion, the timing and intensity of the ENSO quasi-cycle makes or breaks the bet. The surface temperature response to the ENSO/PDO quasi-cycles does tend to favor the originator of the wager. The atmosphere responds differently to the ENSO/PDO than many would expect.

Sensible heating (warming) has a quicker temperature response than sensible cooling as it approaches the latent cooling threshold. So while the GISS temperature shows warming quickly, cooling takes a longer time to happen. There is some correlation between the GISS temperature and the ENSO/PDO, but that is super imposed on a general warming trend. Part of that trend is due to land use/CO2 and part is the natural way the atmosphere responds to sensible cooling. In order to cool, the ENSO/PDO cooling impact has to be enough to cause enough latent atmospheric cooling. Since the Hurricane ACE is low, that part of the latent cooling is not available (which is fine by me).

The difference in the rates of warming and cooling is pretty clearly shown in the temperature record if you compare the slopes of the warming trends to the cooling trends. That means that a lag in cooling relative to ENSO/PDO is somewhat likely, more sever winter storms and chaotic spring storms take longer to get rid of the moisture than a kick butt hurricane season. This makes predicting future climate more complicated and the wager more fun.

The above chart is the GISS global surface temperature in the burgundy color that may look black with the period from 1950 to 1982 in thin line and the rest in thick line. The regression for each period is shown in the same color with the varying thickness. In the orangeish color is the ENSO Data from NASA and in the light blue is the PDO index data from the University of Washington. I have inserted an orange dashed mean line for the ENSO which is pretty close to the PDO index. The chart is pretty busy and I could have picked better colors, but the information is there.

Prior to 1982, there was a better correlation between temperature and the ocean oscillations. After 1982, the temperature trends keeps on heading up with some correlation with ENSO/PDO super imposed on the warming temperature trend. The correlation is not all that great because there are more pieces to the puzzle, but ENSO and or PDO do appear to be players in the puzzle of reasonable significance. It is a wager analysis, so I can take a few liberties.

The more the ENSO/PDO trends falls below the ENSO mean, the more the impact the ENSO and/or PDO appear to have on the temperature trend. So there is a cooling lag, not dependent on time, but dependent on a magic temperature threshold that can change with the overall impact of various forcings both natural and man made. Since the ENSO/PDO values are at the lowest point since 1982 and on a par with the values prior to 1982, there is a reasonable likelihood that the GISS temperature trend can flatten and possibly start cooling if the ENSO/PDO trend continues below the mean of the overall trends.

I call the temperature threshold magic, because I have no idea what its real value is in the current state of the oscillations. I am pretty confident that if the temperature trend starts to cool, that the cooling slope will be less than or equal to the slope of the last cooling trend.

In this chart from before, I weighted the analysis to the near term, because of the wager. The blue line is the regression of GISS global monthly from 2001 and the red line is the regression for the wager start date in 2008. Warming wagers will base their confidence on these trends (pseudo trends if you prefer). The Orange line is the regression starting in 2009, March. The orange pseudo trend was cherry picked to find the most resent regression with roughly the best R squared value. That should be the maximum cooling pseudo trend possible with current conditions. The two dashed trends are the more recent pseudo trends which I use to estimate the more realistic near term path of a cooling trend should it actually develop. The green dashed line is the win line for the guys betting on 2015 average being below 2008 average.

All this boils down to the ENSO/PDO staying at or below the magic temperature threshold. As a reminder, I am not a climate scientist, statistician or psychic, I just enjoy a friendly wager on occasion. Anyway, the climate science professionals may get a kick out of this analysis because when wagering is involved, cherry picking is allowed.

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