2011-09-22 10:45:54Comment at Tamino's
Robert Way

robert_way19@hotmail...
134.153.162.53

I made this comment at Tamino's and was wondering what any of you think of it. Especially the results.

This may be a dumb question but when you say you are subtracting after regression what exactly are you subtracting so that you can know the impact for each variable?

This post here got me thinking about what would be an interesting thought experiment and potentially if it warranted more, some research. Considering we know (and you have demonstrated) that the impacts of Volcanic Eruptions, El Nino and SSNs affect the TLT record why not use them with the SAT to reconstruct the TLT record since the SAT began. I left out using the SSN record because it did not significantly improve the result and I chose to use NOAA because I don’t trust hadley and it regressed better than GISS. Nino 3.4 was used because it was available but in particular I used the winter months (this is done on the annual scale) because that more or less will deal with the lag issue (it seems to have dealt with it). As you can imagine the adjusted R2 is pretty high (about 0.96) so it makes me wonder whether this sort of thing could be a realistic method. I haven’t cross-validated it yet but I will.

Predicted versus actual TLT
http://img37.imageshack.us/img37/5219/predictedtltactual.png

Hindcast Model 1880-2010
http://img200.imageshack.us/img200/9484/predictedtlthindcastmod.png

Predicted versus NOAA
http://img838.imageshack.us/img838/9484/predictedtlthindcastmod.png

2011-09-22 16:34:46
Riccardo

riccardoreitano@tiscali...
93.147.82.133

The underlying assumption is that TLT and SAT are the same thing or, at least, that they always have the same trend. This is not warranted and not well understood; worse, there are reason to believe it does not hold (lapse rate feedback).