2011-05-13 05:59:00Spencer: Weak Warming of the Oceans 1955-2010 Implies Low Climate Sensitivity
oslo

borchinfolab@gmail...
90.149.33.182

Roy Spencer in the low climate sensitivity game:

Weak Warming of the Oceans 1955-2010 Implies Low Climate Sensitivity

I havn't really read through this in detail, but there might be something wrong in the argumentation here. Just a hunch.

2011-05-13 06:51:21
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.97.203
Well I notice a couple of issues. Firstly, it looks like he's calculating transient, not equilibrium sensitivity. Secondly, he's assuming all the energy imbalance is going into the upper 700m of oceans when we know some is going deeper and some is going into the surface (warming air, melting ice, etc.). This is a bit out of my depth so there are probably other mistakes I'm not seeing.
2011-05-13 07:57:02
Riccardo

riccardoreitano@tiscali...
93.147.82.184

It's hard to think that he does not know how to use the heat balance equation. Apparently he really doesn't, though, otherwise he would't publish this garbage.

He assumed that the 700 m ocean are in radiative balance with the atmosphere while the mixed layer depth is on average only about 100 m. And as noted by Dana, he's calculating the transient climate sensitivity, which indeed is known to be somewhere around 1 °C per doubling CO2.

2011-05-13 08:00:40
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.97.203
transient sensitivity is about 2°C, with 1°C at the low end of possible values. What do you think of doing a blog post response to this, Riccardo? Somebody should, but like I said, it's outside my depth.
2011-05-13 08:16:23
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Maybe Barry Bickmore and Arthur Smith could help?  This has all the makings of yet another Spencer blunder.....

2011-05-13 08:25:47
oslo

borchinfolab@gmail...
90.149.33.182

My understanding is that dana has a good point (just learned about transient climate sensitivity through the Lindzen post), always nice to learn something new :-)

Well, as this comment is from a scientist, even if he is a bad one, my thinking is that this should be given some priority?

Which data set is he using anyway? Is there a such continous dataset for such a long period for these depths whith global coverage?

2011-05-13 08:40:34
Riccardo

riccardoreitano@tiscali...
93.147.82.184

Barry Bickmore would be ideal. He already did a lot of work on Spencer and the faulty use of the heat balance equation.

2011-05-13 08:51:46barry
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.97.203

Good point, I'll shoot Barry an email and see if he's interested.

2011-05-13 10:28:11
Alex C

coultera@umich...
67.149.101.148

>>>Is there a such continous dataset for such a long period for these depths whith global coverage?

Domingues 2008 has ocean data.  I find it odd that Spencer is quoting IPCC's AR4 to argue against when more updated OHC data and analyses are available.

2011-05-13 14:20:04
Ari Jokimäki

arijmaki@yahoo...
192.100.112.202

Spencer does the mistake he as a scientist should not do but has done it before in his blog writings - he doesn't research his claims. There has been a few papers recently on deep ocean heat but Spencer is not even looking if the research is there: "While some might claim that it is because warming is actually occurring much deeper in the ocean than 700 m, the vertical profiles I have seen suggest warming decreases rapidly with depth, and has been negligible at a depth of 700 m." Scientist looking into this issue should be able to easily to find the deep ocean heat research. Spencer decided not to look.

 

2011-05-13 14:46:08
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.97.203
Agreed, Ari. It's hard to believe Spencer is unaware of von Schuckmann's work at least. That was the most glaring error I noticed. Assuming 100% of the energy imbalance is going into the upper 700 meters of ocean? Really? I guess you need to make bad assumptions when your goal is to get a lowball sensitivity estimate.
2011-05-13 20:51:00
Alex C

coultera@umich...
67.149.101.148

>>>I guess you need to make bad assumptions when your goal is to get a lowball sensitivity estimate.

Which is exactly what we saw in the Spencer's Great Blunder series.  He assumes unrealistic values for several variables - I would love to see how his model would turn out if he assumed a deeper heat sink and included more accurate data not averaged over a 50+ year period.

2011-05-14 03:55:34
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Got a response from Barry.  He says he'll see what he can come up with.

2011-05-17 03:30:21
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Great!

2011-05-17 06:46:11
MarkR
Mark Richardson
m.t.richardson2@gmail...
134.225.187.197

Should also include the effect of land temperatures (land has warmed about 50% faster. This increases Earth's skin temperature and its blackbody radiation), which boosts his sensitivity estimate by 15%.

 

Also, according to the IPCC 'where is global warming going' figure, you should add another 5-10% to the absorbed heat from melting ice and warming atmosphere/continents. Once you include his ocean down to 2000 metre figures that brings you up to 1.5 C.

 

If there are any slow acting positive feedbacks, then the real value is bigger.

2011-05-17 06:51:13
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Yep Mark, Spencer revised his post to include heat in the deeper oceans, bringing his estimate up to 1.3°C with that one correction alone.  Correcting his many errors brings the value up close to the 2°C transient sensitivity pretty quickly.

2011-05-17 18:11:38
MarkR
Mark Richardson
m.t.richardson2@gmail...
134.225.187.197

I don't see how to get to 2 C. What else should be accounted for? :)

 

But the figures are so uncertain that you can't really tell. And assuming a symmetrical uncertainty distribution in λ, then the uncertainty in sensitivity will be skewed towards the higher end (since that is 1/λ)

2011-05-18 07:20:47
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Note how that one change increased the TCR by 30%  And not too how he keeps hammering away that his values are less than the lower bound of 1.5 C reported in the IPCC AR4.  He doe snot seem to provide a range, is + 1.3 C the mean or median?

God, I hope he is right.....alas, I doubt it very much.

Looking forward to hearing back from Barry...

2011-05-18 07:29:01
Riccardo

riccardoreitano@tiscali...
188.152.84.249

It's not just the data he uses, there's a conceptual flaw in his analysis. You can not use a one box model but force the temperature of the box to that of a small part of it. He's actually adding one more box, the mixed layer, without considering the relevant heat fluxes and response time. If the box is one you have to average any relevant physical quantity over the box.

2011-05-18 07:56:44
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

I've had a few email correspondances with Barry, who's had a few with Spencer.  Barry used the HadSST2 temps, and it resulted in a much larger feedback curve than Spencer's.  Spencer's explanation is that rather than using observed surface temperatures, he generated them with his model using the GISS forcing.  So that may be a significant problem in Spencer's analysis too.

2011-05-18 08:47:20
Riccardo

riccardoreitano@tiscali...
188.152.84.249

How could he generate surface temperature without assuming a climate sensitivity?

2011-05-18 09:33:41
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Hmmm that's a good question.  I didn't get the details on exactly what he did.  But that would seem to present a bit of a conundrum.

2011-05-18 11:30:15
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.97.203
Barry says "he linked the two temperatures together by a factor of 3.5 (so there was only one variable, plus lambda) and generated the temperature values  by running the finite difference model.  He played around with the lambda value until he got something that sort of looked like he wanted it to."
2011-05-18 16:10:50
Riccardo

riccardoreitano@tiscali...
93.147.82.93

Doh! Worse than I thought. He just multiplied his surface temperature by 3.5 thus reducing the sensitivity by the same factor.

2011-05-21 00:53:20
bbickmore

bbickmore@comcast...
67.182.217.158

Would anyone like to critique my response to Roy before I go live?  Here's the link.

http://bbickmore.wordpress.com/2011/05/20/roy-spencers-latest-silver-bullet/

The password is "quartzite".

2011-05-21 02:40:04
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Dear Dr. Bickmore,

Many thanks for this.  It must have taken you quite some time complete this undertaking.  

To be honest this subject is well beyond my area of expertise, but your response reads well and is internally consistent.  It also appears to robustly highlight yet more problems with Dr. Spencer's efforts to arrive at a low value for CS.

It is quite remarkable how many independent lines of evidence arrive at the +3 C number. Is there potential for a paper on using OHC data to estimate/constrain CS?

2011-05-21 03:00:00
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Ah, I didn't see Barry beat me to the punch.  I also made this into an SkS blog post and put it here for comment.