General AGW debate thread

[BethesdaWX]

Well you are talking about a long term correlation.. I'm not. I'm talking about the intra-cycle effect. TSI correlates quite well intra-cycle. It's why we warmed rapidly in the late 90s as TSI ramped up.. and it's why there has been little warming since 2002 when TSI started crashing.

The reason some people have tried to use geomag aa is that it kept going up after the 1950s when TSI peaked. Even though sunspots and TSI haven't gone up (hence the divergence).. geomag aa kept going up so some people have thought that that could be related to the warming. I believe it's just chance, as there is no causative mechanism, and geomagnetic has since crashed but temps have stayed high.

I don't believe any aspect of the sun explains the long term warming. You seem to agree TSI doesn't because TSI plateaued 50+ years ago. But as for geomag aa I believe the correlation is just chance... the correlation has fallen apart the last 15 years, and there is no causative mechanism.

Meanwhile we have a very clear causal mechanism for CO2 that is empirically tested.

Oh you're talking about Intra-Cycle? I apologize, I Misunderstood.

The Geo-AA index didn't crash until 2007/08, and the lag for Geo-AA index/Atmosphere (directly) is longer than that of TSI, as it is 4-8 years. This could be a reason global temps haven't dropped as significantly yet.....also it tales a long time to remove some of that influence.

This is a very good read, actually is Not a Big AGW skeptic. References several papers.

explains the methods and data behind them too.

Definitely a longer Lag-time. Also seperates Sunspots, TSI, Geo-AA, and SurfaceTemps.

http://www.academicjournals.org/ijps/PDF/pdf2010/July/Aly.pdf NOTE: The Study uses GISS Data, not UAH/RSS, and also assumes the PDO/AMO to have no weight.

Its not that there is No Mechanism, we just do not know enough to assess the intricate processes most likely going on...... Example: we don't know why the Geo-Flux Correlates to the NAO......but it does.....very well!

If in the future, the Geo-AA Correlation is Proven to be coincidence, or if it deviates from global temps significantly, I will Definitely have more Faith in Significant AGW.

[Isotherm]

Yeah I work in the energy sector, which is great because I get the chance to do a lot of research on how different factors may or may not be tied together, and then apply that to forecasting. For me, it's much more exciting that your typical 1-7 day forecasting that most mets do, mostly because there are still so many unknowns, so it's like putting together a very complex puzzle.

I do think we will see an increase in solar studies in the next few years, and hopefully we will uncover something. There are definitely a lot of interesting correlations between geo mag / solar flares and atmospheric patterns... just need to get behind the physics of it all. This winter will help because hardly anyone thought we'd see all the blocking we had from late Nov through Jan. It simply doesn't happen with a solid nina / +QBO / warm IO combo, yet it did, and many think the solar stuff probably played some role since low geo mag activity actually correlates better with the NAO than a lot of indices that are commonly used to try and forecast it.

Regarding the NAO-solar connection: I researched Landscheidt's work thoroughly last fall, and used his excellent findings for a large part of my winter outlook. As a result I accurately predicted the -NAO that occurred this winter, in the face of a +QBO/strong Nina signal.

http://www.americanw..._5436#entry5436

We had a great discussion about solar stuff back on the old board, but unfortunately that is lost.

Solar activity has a direct impact on stratospheric circulation patterns, and based upon statistical analyses I did on the NAO-geomagnetic aa index and the geomag aa-QBO, the geomag aa actually has a higher correlation with the NAO. This tells me solar influences can extend downward into the troposphere, regardless of the QBO state, and the weaker/slower than normal north atlantic jet is a product of the low aa environment. In turn, blocking can develop more readily due to the less progressive upper air pattern.

[VAwxman]

Regarding the NAO-solar connection: I researched Landscheidt's work thoroughly last fall, and used his excellent findings for a large part of my winter outlook. As a result I accurately predicted the -NAO that occurred this winter, in the face of a +QBO/strong Nina signal.

http://www.americanw..._5436#entry5436

We had a great discussion about solar stuff back on the old board, but unfortunately that is lost.

Solar activity has a direct impact on stratospheric circulation patterns, and based upon statistical analyses I did on the NAO-geomagnetic aa index and the geomag aa-QBO, the geomag aa actually has a higher correlation with the NAO. This tells me solar influences can extend downward into the troposphere, regardless of the QBO state, and the weaker/slower than normal north atlantic jet is a product of the low aa environment. In turn, blocking can develop more readily due to the less progressive upper air pattern.

I have no doubt this stuff plays a role, and did so this past winter, so don't take this as a too much of a post of disagreement. But the bolded part is the problem to me, as that is not proven. The theory is that it impacts the stratospheric PV and then that is transported to the troposphere, but that is not what went on this year. We actually had a much stronger PV and a colder stratosphere versus normal, so there has to be another mechanism. And that is where it gets murky. There is not a sound explanation as to the physics behind it yet.

[BethesdaWX]

I have no doubt this stuff plays a role, and did so this past winter, so don't take this as a too much of a post of disagreement. But the bolded part is the problem to me, as that is not proven. The theory is that it impacts the stratospheric PV and then that is transported to the troposphere, but that is not what went on this year. We actually had a much stronger PV and a colder stratosphere versus normal, so there has to be another mechanism. And that is where it gets murky. There is not a sound explanation as to the physics behind it yet.

I remember something about MT waves surfacing in the same regions?

Seems like whatever goes on between geomagnetic activity & the NAO/AO is quite intricate. A raging -NAO would be very hard pressed to dominate during a +QBO/+IO/Nina...it just doesnt fit, and a solar min seems to correlate quite well to the recent -NAO plunge.

[VAwxman]

I remember something about MT waves surfacing in the same regions?

Seems like whatever goes on between geomagnetic activity & the NAO/AO is quite intricate. A raging -NAO would be very hard pressed to dominate during a +QBO/+IO/Nina...it just doesnt fit, and a solar min seems to correlate quite well to the recent -NAO plunge.

Right. Granted, we did shoot the block down after January, but for the first half of winter, the way it dominated in the face of all those other factors was quite amazing.

I definitely am not disagreeing with Isotherm's assessment that it was somehow tied into the solar stuff. I just can't find the mechanism. The MT waves off Asia were responsible for some of it, and those were also enhanced by the Asian snowcover, but the NAO block really was cranking even before that was put in place. Interesting stuff, no doubt.

[Isotherm]

Right. Granted, we did shoot the block down after January, but for the first half of winter, the way it dominated in the face of all those other factors was quite amazing.

I definitely am not disagreeing with Isotherm's assessment that it was somehow tied into the solar stuff. I just can't find the mechanism. The MT waves off Asia were responsible for some of it, and those were also enhanced by the Asian snowcover, but the NAO block really was cranking even before that was put in place. Interesting stuff, no doubt.

Definitely agree with you, and I was also searching for the "whys" behind the connection, but couldn't find many papers related to the topic (in fact maybe we're referring to the saem one re: stratospheric vortex). But seeing that type of correlation between two indices is fairly hard to come by in meteorology (during the 80s and 90s the aa and NAO wasn't far from 1 to 1) so I certainly couldn't pass up using it. Even if we don't find out the physical mechanisms behind the strong correlation, I'll probably be using it again considering it worked quite well this winter as a test case.

We know all this stuff is connected somehow, but the hard part is piecing together those individual factors (solar, stratosphere, NAO) with physical reasoning.

The -NAO/-AO of this winter seemed to be much more a product of tropospheric forcings, considering the stratosphere was as hostile as one can get (raging +QBO, strong nina). That's why I'm wondering if the low aa can actually cause the north atlantic jet to become weaker than normal, and I believe this was speculated in one paper but there's no definitive evidence as you noted.