2011-09-26 19:30:08The Deep Ocean Warms When Global Surface Temperatures Stall
Rob Painting

Yeah, real clunky title, it's a 'work on'. Post is here.  

2011-09-27 01:51:50
Mark Richardson

I wonder from the Fig. 2 inset, is this 'missing heat' haunting us, or just that radiative imbalance has grown and you're measuring from the trough of natural temperature swings?

2011-09-27 04:47:54
Rob Painting

Mark - bingo!  

2011-09-27 05:08:33
Julian Brimelow

Rob, nice post.

My only concern is the two haitus periods that you show-- you know some might make accusations of cherry-picking or something. Are those shaded areas based on dates specified in the paper?


Maybe you can help we understand something, b/c you ahve worked on this so much of late.  If that heat is being sequestered deeper down, what in a few years is going to lead to rapid wamring again?  Is some fraction of that sequestered heat returned to near thesurface or near the surface?  that Fig. 4 looks very similar to the loading psattern for PDO and ENSO (not sure about S. Hemi.), so is that what we are seeing?  I wonder if the ARGO data for the last 5 years or so show this spatial pattern?  That would be a great find if so, b/c then we would have confirmaton and a much better idea of what is going on.

Talking of Fig 4. the captions says "Figure 4 - Composite average sea surface temperature trends for hiatus decades"  but is also shows temperatures over land.

I think that some statement should be made in the post to address claims made by Pielke and others that this finding suggests that climate sensitivity is lower and that that heat will not come back to "haunt" us any time soon.

"So at some point in the very near future we can expect surface temperatures to gather up a head of steam, and begin rising at a rapid rate. "

This sounds a little too confident.  Maybe preface it with some cautionary language..."may", "could be", "likely"....

Any thoughts on the role being played by aerosols?

2011-09-27 17:31:01
Rob Painting

Alby, this is the way Jerry Meehl explained it to me:

"Maybe the way to visualize this is picture a plot of a sine wave with a long term average of zero. The ups and downs of the sine wave occur around that zero line. Then start tilting the whole sine wave plot upwards. Now the downs of the sine wave are nearly level, and the ups  are much more steep. That's more of less what is happening in the climate system. There are natural ups and downs of the temperature time  series, but when you tilt it upwards (the long term warming trend), the naturally occurring downs are now nearly level, and the ups are more steep. So we have a system that naturally produces these ups and downs, and we've superimposed a long term warming trend that changes how we experience the natural ups and downs"

And yes, you are correct about the pattern during hiatus periods resembling the PDO. I chose not to mention that because I have a sneaky suspicion it will encourage skeptic comments waffling on about the PDO. 

I thought about two graphics to demonstrate this, (sine wave) but my graphical learning curve is slow, and I don't have that much time to spend on it at the moment. I will dedicate a post to this in the future though.

Fig 4. - whoops. Fixed.

Pielke - will be addressed in the Pielke's Cherrypicks, or if that doesn't eventuate - another post.

Good point about the ending. Fixed.

Aerosols - I suspect they have definitely played a part, but I'm still awaiting the publication of a few aerosol papers.

I was thinking of a post or two wrapping together the ocean heat content bizzo, and seperate posts on the noughties slowdown, as suggested by aerosols. I wonder if the hiatus would have been virtually no hiatus at all, but for aerosol-induced global dimming?  


2011-09-27 17:57:09
Rob Painting

Oh, and the two periods were chosen beacuse these were decade-long periods where surface temperatures had a small (0.1 °C) negative trend.

I've amended the text accordingly. Cheers.

2011-09-27 18:52:56
Glenn Tamblyn


Nice post Rob. Really interesting study.

What would have been really neat is if Meehl had unpacked the historical XBT data into 0-300 & 300-700m curves. Since the most striking feature of their bar graph from the models is the big difference between those two layers, this should be observable in the historical xbt data.  Oh to have had ARGO operational 20 years earlier.

It might be worth expanding a little on the underlying mechanism. For a layman it is really counter-intuitive. How can the heat get to these deeper layers if the upper layer isn't warming much? To many people that idea doesn't make sense. So simply likening it to ENSO isn't explanatory enough for most people.

This is potentially a REALLY important paper. What will be interesting to watch is how our understanding of the underlying fluid-mechanics of this pans out - can we extract from the models more about why this pattern occurs. Given the size of the difference between the top 2 layers, a serious chunk of climate variability is locked up in there.

2011-09-27 19:05:58
Rob Painting

Thanks Glenn. Agreed, I was hoping to track down data to confirm the modeling, but haven't had the time yet. Another excuse to write a follow up to this.

As for explaining the mechanism - yeah, I get ya. Shouldn't take too much - the problem is looking at the OHC in layers completely ignores the upwelling & downwelling components. I think this too, will have to be addressed in the follow up - I have an idea for graphics to illustrate the point.

And yes I agree, this may be a significant paper - we're honing in on why the climate naturally varies.  

2011-09-29 06:57:46
Dana Nuccitelli

Very interesting Rob.  My only comment is Figure 1 - the two black lines confused me (I thought they were an arrow or something) until I figured out they were labeling the hiatus decades.  Think you can modify that figure to make it clearer?

Let me know when this one's ready to publish.

2011-09-29 16:48:32
Rob Painting

Bah, had a feeling someone would take issue with that! Now sorted.

Ready to roll. I'll have to write a follow-up to this to cover the valid points Glenn raised, and to highlight the natural variability aspect as explained by Jerry Meehl. I'll link back to this in the green box.

I'll eventually turn a few of these posts into rebuttals. Be nice to bury Pielke's nonsense with specific rebuttals.