2011-03-05 12:33:50The name is Bond... Girard Bond. (draft article)
Rob Honeycutt

robhon@mac...
98.207.62.223

Here is a first draft of a post on Bond et al 1997.

It still needs a good bit of work but I'd like to get some comments.

2011-03-05 13:36:43
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.202.208

Whaaaaaat?, no Pussy Galore?.

I think you need to explain what GISP2 is first, but nevertheless a great post. And no, can't help with a source for halving the temp records.

2011-03-05 15:27:47
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

1. In this paragraph you have a superfluous letter "a" (implies a singular event in context):

Many of you may be familiar with Dansgaard-Oeschger (D-O) events.  These are the rapid climate change events we see in the ice core data during glacial periods.  They easily recognizable in the GISP2 core as a rapid warming followed by slower cooling, following a 1470 (+/-) year cycle. D-O events are also notable in the climate record as being a redistribution within the climate system because they are also found in Antarctic cores with a corresponding but reverse signal (called an "antiphase").  That is, warming followed by cooling in the north, and cooling followed by warming in the south.  This is not the planet heating up suddenly and then cooling off.  It's the planet rearranging how heat is distributed within the overall climate system.

I suggest switching it to "by" (path-of-least-resistance fix):

Many of you may be familiar with Dansgaard-Oeschger (D-O) events.  These are the rapid climate change events we see in the ice core data during glacial periods.  They easily recognizable in the GISP2 core by rapid warming followed by slower cooling, following a 1470 (+/-) year cycle. D-O events are also notable in the climate record as being a redistribution within the climate system because they are also found in Antarctic cores with a corresponding but reverse signal (called an "antiphase").  That is, warming followed by cooling in the north, and cooling followed by warming in the south.  This is not the planet heating up suddenly and then cooling off.  It's the planet rearranging how heat is distributed within the overall climate system.

2. Colors are much more pronounced on Figure 1, much more washed out on Figure2.  Also, you'll need a color key to identify more clearly which is which (GISP2 or Vostok).  I suggest changing the text label color along the appropriate edge to the same as the on the chart, i.e., Vostok in purple, GISP2 in red (or whichever is which...I dunno looking at the graphs...)

3.  Still need your source for the cite (once you get it, it might be better to put it into the form of a quoted sound-bite):

We have to be careful to understand this when looking at the warming we see taking place now.  Most climatologists believe that [need a source for this] that halving the temperature record we see in the Vostok core, or the EPICA Dome C core paints a more reasonable picture of temperature during the Holocene.

 

I'd also re-phrase it slightly to:

We have to be careful to understand this when looking at the warming we see taking place now.  Most climatologists believe that [need a source for this] that halving the temperature record we see in the Vostok and EPICA Dome C cores paints a more reasonable picture of temperature during the Holocene.

2011-03-05 16:01:02Comments
John Cook

john@skepticalscience...
124.186.229.6
Nice bit of work putting this together. Now I know I plotted the graphs in the first place but I'm not so sure about the different axes - perhaps it's better if you work out the GISP data as temperature anomaly rather than absolute temperature. Eg - work out the average of the entire series then calculate the difference between each data point and the average. Problem is I don't know what the base period for the Vostok series is either. I'm not sure if any of this matters but people might raise their eyebrows at two different axes and it might be a potential distraction.

Not sure about the hockey team line at the end.

2011-03-05 18:35:33
nealjking

nealjking@gmail...
91.33.103.53

"There is still much that is not well understood about what drives both D-O and Bond events.  They are well accepted in the literature and are curious because of the regularity with which the occur."

=>

"There is still much that is not well understood about what drives both D-O and Bond events.  They are well accepted in the literature and are curious because of the regularity with which they occur."

=================================================

"When we start reconciling these records we find, yes, there are dramatic and rapid climate change events in the Holocene. Larger changes tend to occur in the high latitudes of the northern hemisphere while the southern hemisphere remains more stable with occasional redistributions of temperature from the north.  But the planet as a whole is not suddenly warming for unknown reasons."

=>

"When we start reconciling these records we find, yes, there are dramatic and rapid climate change events in the Holocene. Larger changes tend to occur in the high latitudes of the northern hemisphere while the southern hemisphere remains more stable with occasional redistributions of temperature from the north.  But the planet as a whole is not suddenly warming for unknown reasons during these events."

=================================================

"We have to be careful to understand this when looking at the warming we see taking place now.  Most climatologists believe that [need a source for this] that halving the temperature record we see in the Vostok core, or the EPICA Dome C core paints a more reasonable picture of temperature during the Holocene."

What do you mean by "halving" the temperature record? Dividing the time period in 2? Dividing the temperature by 2 ? and why?

=================================================

"Dare I say it?  I think Bond has joined the Hockey Team."

I would skip this:

- "Hockey Team" is a pejorative term used by the CA folks.

- Bond may take offence at this designation.

2011-03-06 03:24:13
Rob Honeycutt

robhon@mac...
98.207.62.223

Thanks guys!  I think I may drop the bit about halving the Vostok core.  It's a rather weak argument and drifts from the central topic.  And I'll drop the hockey team bit too.

Mostly I'm grappling with a good way to close.

Daniel the washed out effect was something I was trying to do.  The graphic gets a bit too busy and you can't really see the events I'm trying to point out.  So I was trying to gray out the other parts.  Perhaps I need to work on this a bit more.

2011-03-06 03:39:27
nealjking

nealjking@gmail...
91.33.103.53

- You give a reasonable definition of the D-O events, but I don't see a clear explanation of what constitutes a Bond event. You say it's similar but lesser, and has something to do with debris. That doesn't give me a very clear concept.

- You relate the graphs to the MWP and the RWP, without providing any way to look for this correlation. Maybe if I were given the dates?

- To generate a good sign-off line, you need a good take-away message. What is it?

2011-03-06 08:23:54
Rob Honeycutt

robhon@mac...
98.207.62.223

Did some updating on this. It still feels like it's not done.  It's lacking a strong close. Maybe it's okay, I'd just love for the last line to have a bit more punch.

I did get Pussy Galore in for Rob Painting (sorta kinduv).

Still need to work on the second graphic.

Still need to add some links to various outside sources.

For John, I did a bunch of work on the numbers before I did these charts. I dropped all the data for both records prior to 10k. I've noticed that Bond event 5 lines up almost identical to where I've seen it in other charts. So, it's probably not good enough for a real peer review but I think it's pretty close. 

I'm leaving in the two trend lines just as an added bonus to show people that the southern records are not changing as rapidly as the Greenland ice cores.

I'm not sure changing the GISP2 data to an anomaly would help. The scale of the two records is the same in that 1C = 1C.  But you have to keep them a bit offset from each other on the chart in order to clearly see the different events. The most accurate way would be to keep the two complete separate so they don't touch.  But then the lines are so small it's hard to read.

I'm certainly open to suggestions on how to make the graphs easier to read.

2011-03-06 08:24:30
Chris Colose

colose@wisc...
69.71.240.186

Hi Rob, good post so far but could use some expansion.  Here are some initial impressions

1) I would source your data, or if your graph came from a particular paper, that paper.  When you talk about "halving the temperature record" what you are probably refering to is making an assumption that the global temperature is roughly linearly related to the local Vostok temperature by a factor of 0.5 (polar amplification effect).  Hansen's "Target CO2: Where should humanity aim" does this (and cites a paper that you can follow) although clearly it's not a universal theoretical constraint that the climate must follow throughout the whole record, so if you plot things in that way I think it's fine but I'd lay out your assumptions.

2) There's a potential source of confusion between the Bond events over the Holocene as you've laid it out, and Bond cycles usually discussed in the context of the D-O:Heinrich event process in the last glaciation.  Briefly, Bond cycles often refer to a sequence of D-O events (which themselves can exhibit a trend such that one D-O event is progressively colder than the last one) and then finally a Heinrich layer appears to complete the sequence (see e.g. Richard Alley's 2007 paper in Annual Review of Earth and Planetary Sciences).  The terminology is confusing, even in the literature, which is why I point it out here.

3) There is a fair degree of skepticism concerning the existence or importance of this "1500 year" stuff over the Holocene.  For instance, just as an example comment by Eric Steig at RC once: "There is no evidence of this “cycle’s” existence in the Holocene (last 11,000 years). What Bond showed is that there are quasi-cycles that Bond argued have the same cause as the ones during the glacial period. Personally, I’m very skeptical about this, but it is just a matter of conjecture on both parts. Unfortunately Gerard Bond died last year so he can’t defend himself." 

I'm also posting a personal exchange with Richard Alley I had a few years ago on this (please don't post this elsewhere).  You could paraphrase, but it's also good to make a connection to those people who will inevitably connect this alleged "cycle" to modern global warming, as some have inappropriately done:

 

"If there is a 1500-year cycle in the climate system during the Holocene, the cycle is very weak, so we have to look really carefully to see it and there is a lot of argument about the reality or not. No consensus has emerged on existence despite an immense number of studies, so any signal must be very small. Because any signal appears very small compared to the muted natural variability of the climate over the most recent millennia, the idea seems quite far-fetched that any influence of this possible-but-unproven natural cycle would suddenly become so huge as to swamp out the natural variability that has obscured it in the past and the strong changes expected from human influence. Scientifically, a 1500-year cycle would be interesting; it points towards “new physics”, and we love new things. But for prediction, I would not rely on it. Because we don’t know whether it is or not, we don’t know where we are in the cycle if it is, so we don’t know which way it would be going naturally. -- Richard"


In any event, if you stick to what you are doing, I would talk a bit more about mechanisms or "why people care."  There are skeptics who have abused this (Singer and Avery have emphasized the 1500 year cycles in their nonsense before) so if you want to make connections to skeptics, that could be a good starting point.

4) The "8.2k" event may be correlative with a particular "Bond event" but it's not clear to me that they are as dependent as you imply in this post.  The explanation for the 8.2k event is a catastrophic flood (e.g., Clarke et al., 2004) which doesn't necessitate any cyclic process within the climate system, and so could be completely coindicidental with another forcing that happens to have the same sign (if this is indeed what is happening and the timing is accurate enough to truely be synchronous).  There's been a lot of work on the 8.2k event since Bonds paper in the late '90s.

Hope that helps

2011-03-06 08:45:35
Rob Honeycutt

robhon@mac...
98.207.62.223

Chris...  That helps a ton!  It's really a pretty complex issue.  I think my approach here is more to use Bond events to illustrate that you can't just look at single records of temperature.  But being accurate about the science is obviously important.

2011-03-06 09:44:06
Rob Honeycutt

robhon@mac...
98.207.62.223

Chris...  Do you think it's fair to hone in on the antiphase nature of these and other events in the ice core records the way I'm going?

The driver of the events is less concern to me with regards to this article.  I'm looking more to suggest that Bond events, D-O events and other antiphased events are showing us that 1) the global climate system is dynamic, and 2) heat moves around the planet in mysterious ways.

Most importantly I want to drive home the idea that you can't look at the GISP2 or another individual NH proxy and think you're looking at a history of global temperature.

2011-03-06 13:16:45
Chris Colose

colose@wisc...
69.71.240.186

Rob, if that is your only point I think you're going through a rather round-a-bout way, and the the glacial abrupt climate changes are probably a better template for a clear and unambiguous see-saw pattern.  The Holocene Bond events are not well known especially in the blogosphere, which is fine (I like to communicate things which aren't well-known or popularly misunderstood myself) but I think you need a better rationale for it than just "the climate is dynamic" and "one temperature record is not a global record" which has been covered a million times before.  Perhaps if you connect it to skeptical claims about natural variability, like the Avery and Singer writings, you'd be making a better point.  It is of course your post though.

Another obvious point is that while causes may not be your concern, the global distribution of the temperature change is intimately related to the nature of the forcing (e.g, a large rise in CO2 vs. a collapse of the THC will have different spatio-temporal patterns in terms of the response).  This was a point I emphasized in my guest post at RealClimate on the Younger Dryas

http://www.realclimate.org/index.php/archives/2010/07/revisiting-the-younger-dryas/

which might also help piecing together your thoughts...

Chris

2011-03-08 12:39:01updated
Rob Honeycutt

robhon@mac...
98.207.62.223

Would folks take a gander at this updated version of Bond, Gerald Bond and give some criticism.

I didn't make huge revisions.  I'm trying to put forth the idea that Bond events help us (the general audience) to understand that climate is dynamic within the holocene but what's going on today is different that what we see occurring naturally.

2011-03-09 10:28:22comments
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

 I'd suggest formatting the secton headings as Heading 3.

"They are easily recognizable in the GISP2 core by rapid warming followed by slower cooling, following a 1470 (+/-) year cycle".  As I recall, it's +/- about 10%, so would it be accurate to revise this to read "1470 +/- 150 year cycle"?

"That is, warming followed by cooling in the north, and cooling followed by warming in the south."  Seems like this should more accurately read something like "warming in the north simultaneous to cooling in the south, and vice-versa".  It might be better to replace north and south with Arctic and Antarctic, too.

"view to a kill" => is that a Bond phrase?

Overall, good post!

2011-03-09 11:34:30Heh
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

View To A Kill is both a James Bond movie and the title track to the movie by Duran Duran.

And yes, I'm showing my age by that admission of knowledge (no Googling req'd).

2011-03-09 17:41:00
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.231.184

Is that the one where Bonds car get rammed, snaps in two and he's driving around Paris with only the front half?. Man, pissed myself laughing when I first saw that. 

2011-03-09 18:54:49
nealjking

nealjking@gmail...
91.33.114.132

I still don't get a clear idea of what you specifically mean by "a Bond event".

Where is it defined?

2011-03-10 06:54:55
Rob Honeycutt

robhon@mac...
98.207.62.223

Neal...  A Bond event, as I understand it, is technically a "pulse" event in the north Atlantic of debris that shows up in sea bottom cores and are closely related to warming events shown in the Greenland ice core records.  I believe they are called Bond events because it was Bond that originally identified these IRD pulses and associated them with a lesser version of a D-O event during the Holocene.

But like I say in the article, these are still apparently being hotly debated within the scientific community.  And I believe that is primarily because the events are so mild in comparison to D-O events, so it's still really hard to pin down exactly what's going on.

It would be great if I could be more definitive on the bipolar seesaw nature of temperature during the Holocene but I think the science is not quite there yet.

I'll see if I can reword that paragraph describing Bond events to clarify it better.

Dana...  I will make adjustments to the paragraph you noted.  Thanks!