From: Tim Osborn To: Keith Briffa , Edward Cook Subject: Fwd: Re: Fwd: Soon & Baliunas Date: Wed Sep 3 15:54:41 2003 Hi Ed, first all, yes I agree that we need a paper that takes a more objective look at where we are now and how we can take things forward in terms of NH temperature reconstructions (and possibly global, SH, spatial etc.). As Keith said, we (mainly I so far) have been planning our version of this (hopefully) "objective assessment", and by chance I was sketching out a vague outline of its possible content. We've been keeping this fairly close to our chests for now, so please keep our plans/ideas to yourself for the moment. There is partial overlap between our ideas and yours, so it might be good to do this jointly. Anyway, my current ideas are a number of forum articles, the first comparing existing reconstructions but without going into more depth, and the other three looking at the way forward (i.e. what should we attempt to do to improve them): Forum piece (1): Comparison of existing reconstructions This has most overlaps with your ideas, though I hadn't thought of it being so comprehensive. I was thinking more of: (a) comparing original series. (b) comparing them after our recalibration to common target data, including discussion of why some things don't change much (e.g. relative positioning of reconstructions), though amplitudes can change - and of course the comparison of Mann et al. with and without oceans/tropics. (c) maybe a bit on comparison with boreholes, though maybe not. (d) uncertainty estimates and how these may decrease with time scale and hence not all reconstructions lie in the Mann et al. uncertainty ranges. Forum piece (2): Selection of predictand and predictor data (a) What to try to reconstruct and why it matters - e.g. will we get the wrong spectral shape if we reconstruct ocean SST from land-based proxies. Plus some on seasonality, though Jones, Osborn and Briffa cover part of that issue (are you aware of that paper, in press with JGR?). (b) What proxies should be used - e.g. does throwing in "poor" proxies cause a problem with simple averaging, weighted averaging and multivariate regression approaches. Plus does using precipitation proxies to reconstruct temperature result in the wrong spectral shape? Forum piece (3): Reconstruction methods Something here on different methods (simple averaging, multivariate regression type approaches) and different implementation choices (e.g. calibration against trends/filtered data). Not entirely sure about this, but it would not be new work, just would critically appraise the methods used to date and what their theoretical/potential problems/advantages might be. Forum piece (4): Estimating uncertainty Again, not entirely sure yet, but this must emphasise the absolute requirement to estimate AND USE uncertainty when comparing reconstructions against observations or simulations etc. Then something about how to do it, contrasting using calibration residuals, verification residuals, parameter uncertainty, with the type of approach that you've taken (bootstrap uncertainty, or measures of the EPS) to look at the common signal, with additional uncertainty of how the common signal differs from the predictand. So that's it!! Perhaps rather ambitious, so maybe a reduction to certain key points might be required. I was deliberately avoiding any review of tree-ring contributions and low-frequency per se, thinking that you and Keith would be taking the lead on that kind of review. One final think to mention, is that the emails copied below and the attached file might be of interest to you as an example of something that *might* go in a comparison paper of existing reconstructions. It's shows how the recalibrated average of existing reconstructions differs from the average of existing calibrated reconstructions. You'll see from Mike Mann's initial request below that he was thinking of it as a contribution to the EOS rebuttal of Soon and Baliunas, but I've not heard much from him since. Also Tom Crowley was very interests in this composite of the reconstructions, and I started to converse with him about it but never finished estimating the uncertainty range on the composite series and kind of stopped emailing him. But I guess either of them might reproduce this idea sometime, if it suits them. A visit to talk face to face about all these things would be good. Keith and I have been talking about how to fit a visit in. Cheers Tim Date: Wed, 12 Mar 2003 16:16:16 +0000 To: "Michael E. Mann" , Tom Crowley , Phil Jones From: Tim Osborn Subject: Re: Fwd: Soon & Baliunas Cc: Malcolm Hughes , rbradley@geo.umass.edu, mhughes@ltrr.arizona.edu, srutherford@gso.uri.edu, k.briffa@uea.ac.uk, mann@virginia.edu This is an excellent idea, Mike, IN PRINCIPLE at least. In practise, however, it raises some interesting results (as I have found when attempting this myself) that may be difficult to avoid getting bogged down with discussing. The attached .pdf figure shows an example of what I have produced (NB. please don't circulate this further, as it is from work that is currently being finished off - however, I'm happy to use it here to illustrate my point). I took 7 reconstructions and re-calibrated them over a common period and against an observed target series (in this case, land-only, Apr-Sep, >20N - BUT I GET SIMILAR RESULTS WITH OTHER CHOICES, and this re-calibration stage is not critical). You will have seen figures similar to this in stuff Keith and I have published. See the coloured lines in the attached figure. In this example I then simply took an unweighted average of the calibrated series, but the weighted average obtained via an EOF approach can give similar results. The average is shown by the thin black line (I've ignored the potential problems of series covering different periods). This was all done with raw, unsmoothed data, even though 30-yr smoothed curves are plotted in the figure. The thick black line is what I get when I re-calibrate the average record against my target observed series. THIS IS THE IMPORTANT BIT. The *re-calibrated* mean of the reconstructions is nowhere near the mean of the reconstructions. It has enhanced variability, because averaging the reconstructions results in a redder time series (there is less common variance between the reconstructions at the higher frequencies compared with the lower frequencies, so the former averages out to leave a smoother curve) and the re-calibration is then more of a case of fitting a trend (over my calibration period 1881-1960) to the observed trend. This results in enhanced variability, but also enhanced uncertainty (not shown here) due to fewer effective degrees of freedom during calibration. Obviously there are questions about observed target series, which series to include/exclude etc., but the same issue will arise regardless: the analysis will not likely lie near to the middle of the cloud of published series and explaining the reasons behind this etc. will obscure the message of a short EOS piece. It is, of course, interesting - not least for the comparison with borehole-based estimates - but that is for a separate paper, I think. My suggestion would be to stick with one of these options: (i) a single example reconstruction; (ii) a plot of a cloud of reconstructions; (iii) a plot of the "envelope" containing the cloud of reconstructions (perhaps also the envelope would encompass their uncertainty estimates), but without showing the individual reconstruction best guesses. How many votes for each? Cheers Tim At 15:32 12/03/03, Michael E. Mann wrote: p.s. The idea of both a representative time-slice spatial plot emphasizing the spatial variability of e.g. the MWP or LIA, and an EOF analysis of all the records is a great idea. I'd like to suggest a small modification of the latter: I would suggest we show 2 curves, representing the 1st PC of two different groups, one of empirical reconstructions, the other of model simulations, rather than just one in the time plot. Group #1 could include: 1) Crowley & Lowery 2) Mann et al 1999 3) Bradley and Jones 1995 4) Jones et al, 1998 5) Briffa et al 200X? [Keith/Tim to provide their preferred MXD reconstruction] 6) Esper et al [yes, no?--one series that differs from the others won't make much of a difference] I would suggest we scale the resulting PC to the CRU 1856-1960 annual Northern Hemisphere mean instrumental record, which should overlap w/ all of the series, and which pre-dates the MXD decline issue... Group #2 would include various model simulations using different forcings, and with slightly different sensitivities. This could include 6 or so simulation results: 1) 3 series from Crowley (2000) [based on different solar/volcanic reconstructions], 2) 2 series from Gerber et al (Bern modeling group result) [based on different assumed sensitivities] 1) Bauer et al series (Claussen group EMIC result) [includes 19th/20th century land use changes as a forcing]. I would suggest that the model's 20th century mean is aligned with the 20th century instrumental N.Hem mean for comparison (since this is when we know the forcings best). I'd like to nominate Scott R. as the collector of the time series and the performer of the EOF analyses, scaling, and plotting, since Scott already has many of the series and many of the appropriate analysis and plotting tools set up to do this. We could each send our preferred versions of our respective time series to Scott as an ascii attachment, etc. thoughts, comments? thanks, mike At 10:08 AM 3/12/2003 -0500, Michael E. Mann wrote: Thanks Tom, Either would be good, but Eos is an especially good idea. Both Ellen M-T and Keith Alverson are on the editorial board there, so I think there would be some receptiveness to such a submission.t I see this as complementary to other pieces that we have written or are currently writing (e.g. a review that Ray, Malcolm, and Henry Diaz are doing for Science on the MWP) and this should proceed entirely independently of that. If there is group interest in taking this tack, I'd be happy to contact Ellen/Keith about the potential interest in Eos, or I'd be happy to let Tom or Phil to take the lead too... Comments? mike At 09:15 AM 3/12/2003 -0500, Tom Crowley wrote: Phil et al, I suggest either BAMS or Eos - the latter would probably be better because it is shorter, quicker, has a wide distribution, and all the points that need to be made have been made before. rather than dwelling on Soon and Baliunas I think the message should be pointedly made against all of the standard claptrap being dredged up. I suggest two figures- one on time series and another showing the spatial array of temperatures at one point in the Middle Ages. I produced a few of those for the Ambio paper but already have one ready for the Greenland settlement period 965-995 showing the regional nature of the warmth in that figure. we could add a few new sites to it, but if people think otherwise we could of course go in some other direction. rather than getting into the delicate question of which paleo reconstruction to use I suggest that we show a time series that is an eof of the different reconstructions - one that emphasizes the commonality of the message. Tom Dear All, I agree with all the points being made and the multi-authored article would be a good idea, but how do we go about not letting it get buried somewhere. Can we not address the misconceptions by finally coming up with definitive dates for the LIA and MWP and redefining what we think the terms really mean? With all of us and more on the paper, it should carry a lot of weight. In a way we will be setting the agenda for what should be being done over the next few years. We do want a reputable journal but is The Holocene the right vehicle. It is probably the best of its class of journals out there. Mike and I were asked to write an article for the EGS journal of Surveys of Geophysics. You've not heard of this - few have, so we declined. However, it got me thinking that we could try for Reviews of Geophysics. Need to contact the editorial board to see if this might be possible. Just a thought, but it certainly has a high profile. What we want to write is NOT the scholarly review a la Jean Grove (bless her soul) that just reviews but doesn't come to anything firm. We want a critical review that enables agendas to be set. Ray's recent multi-authored piece goes a lot of the way so we need to build on this. Cheers Phil At 12:55 11/03/03 -0500, Michael E. Mann wrote: HI Malcolm, Thanks for the feedback--I largely concur. I do, though, think there is a particular problem with "Climate Research". This is where my colleague Pat Michaels now publishes exclusively, and his two closest colleagues are on the editorial board and review editor board. So I promise you, we'll see more of this there, and I personally think there *is* a bigger problem with the "messenger" in this case... But the Soon and Baliunas paper is its own, separate issue too. I too like Tom's latter idea, of a more hefty multi-authored piece in an appropriate journal (Paleoceanography? Holocene?) that seeks to correct a number of misconceptions out there, perhaps using Baliunas and Soon as a case study ('poster child'?), but taking on a slightly greater territory too. Question is, who would take the lead role. I *know* we're all very busy, mike At 10:28 AM 3/11/03 -0700, Malcolm Hughes wrote: I'm with Tom on this. In a way it comes back to a rant of mine to which some of you have already been victim. The general point is that there are two arms of climatology: neoclimatology - what you do based on instrumental records and direct, systematic observations in networks - all set in a very Late Holocene/Anthropocene time with hourly to decadal interests. paleoclimatology - stuff from rocks, etc., where major changes in the Earth system, including its climate, associated with major changes in boundary conditions, may be detected by examination of one or a handful of paleo records. Between these two is what we do - "mesoclimatology" - dealing with many of the same phenomena as neoclimatology, using documentary and natural archives to look at phenomena on interannual to millennial time scales. Given relatively small changes in boundary conditions (until the last couple of centuries), mesoclimatology has to work in a way that is very similar to neoclimatology. Most notably, it depends on heavily replicated networks of precisely dated records capable of being either calibrated, or whose relationship to climate may be modeled accuarately and precisely. Because this distinction is not recognized by many (e.g. Sonnechkin, Broecker, Karlen) we see an accumulation of misguided attempts at describing the climate of recent millennia. It would be better to head this off in general, rather than draw attention to a bad paper. After all, as Tom rightly says, we could all nominate really bad papers that have been published in journals of outstanding reputation (although there could well be differences between our lists). End of rant, Cheers, Malcolm > Hi guys, > > junk gets published in lots of places. I think that what could be > done is a short reply to the authors in Climate Research OR a SLIGHTLY > longer note in a reputable journal entitled something like "Continuing > Misconceptions About interpretation of past climate change." I kind > of like the more pointed character of the latter and submitting it as > a short note with a group authorship carries a heft that a reply to a > paper, in no matter what journal, does not. > > Tom > > > > > Dear All, > > Apologies for sending this again. I was expecting a stack of > >emails this morning in > > response, but I inadvertently left Mike off (mistake in pasting) > >and picked up Tom's old > > address. Tom is busy though with another offspring ! > > I looked briefly at the paper last night and it is appalling - > >worst word I can think of today > > without the mood pepper appearing on the email ! I'll have time to > >read more at the weekend > > as I'm coming to the US for the DoE CCPP meeting at Charleston. > >Added Ed, Peck and Keith A. > > onto this list as well. I would like to have time to rise to the > >bait, but I have so much else on at > > the moment. As a few of us will be at the EGS/AGU meet in Nice, we > >should consider what > > to do there. > > The phrasing of the questions at the start of the paper > >determine the answer they get. They > > have no idea what multiproxy averaging does. By their logic, I > >could argue 1998 wasn't the > > warmest year globally, because it wasn't the warmest everywhere. > >With their LIA being 1300- > >1900 and their MWP 800-1300, there appears (at my quick first > >reading) no discussion of > > synchroneity of the cool/warm periods. Even with the instrumental > >record, the early and late > > 20th century warming periods are only significant locally at > >between 10-20% of grid boxes. > > Writing this I am becoming more convinced we should do > >something - even if this is just > > to state once and for all what we mean by the LIA and MWP. I think > >the skeptics will use > > this paper to their own ends and it will set paleo back a number of > > > >years if it goes > > unchallenged. > > > > I will be emailing the journal to tell them I'm having > >nothing more to do with it until they > > rid themselves of this troublesome editor. A CRU person is on the > >editorial board, but papers > > get dealt with by the editor assigned by Hans von Storch. > > > > Cheers > > Phil > > > > Dear all, > > Tim Osborn has just come across this. Best to ignore > >probably, so don't let it spoil your > > day. I've not looked at it yet. It results from this journal > >having a number of editors. The > > responsible one for this is a well-known skeptic in NZ. He has let > > > >a few papers through by > > Michaels and Gray in the past. I've had words with Hans von Storch > > > >about this, but got nowhere. > > Another thing to discuss in Nice ! > > > > Cheers > > Phil > > > >>X-Sender: f055@pop.uea.ac.uk > >>X-Mailer: QUALCOMM Windows Eudora Version 5.1 > >>Date: Mon, 10 Mar 2003 14:32:14 +0000 > >>To: p.jones@uea > >>From: Tim Osborn > >>Subject: Soon & Baliunas > >> > >> > >> > >>Dr Timothy J Osborn | phone: +44 1603 592089 > >>Senior Research Associate | fax: +44 1603 507784 > >>Climatic Research Unit | e-mail: t.osborn@uea.ac.uk > >>School of Environmental Sciences | web-site: University of East > >>Anglia __________| [1]http://www.cru.uea.ac.uk/~timo/ Norwich NR4 > >>7TJ | sunclock: UK | > >>[2]http://www.cru.uea.ac.uk/~timo/sunclock.htm > > > >Prof. Phil Jones > >Climatic Research Unit Telephone +44 (0) 1603 592090 > >School of Environmental Sciences Fax +44 (0) 1603 507784 > >University of East Anglia > >Norwich Email p.jones@uea.ac.uk > >NR4 7TJ > >UK > >--------------------------------------------------------------------- > >------- > > > > > >Attachment converted: Macintosh HD:Soon & Baliunas 2003.pdf (PDF > >/CARO) (00016021) > > > -- > Thomas J. Crowley > Nicholas Professor of Earth Systems Science > Dept. of Earth and Ocean Sciences > Nicholas School of the Environment and Earth Sciences > Box 90227 > 103 Old Chem Building Duke University > Durham, NC 27708 > > tcrowley@duke.edu > 919-681-8228 > 919-684-5833 fax Malcolm Hughes Professor of Dendrochronology Laboratory of Tree-Ring Research University of Arizona Tucson, AZ 85721 520-621-6470 fax 520-621-8229 _______________________________________________________________________ Professor Michael E. Mann Department of Environmental Sciences, Clark Hall University of Virginia Charlottesville, VA 22903 _______________________________________________________________________ e-mail: mann@virginia.edu Phone: (434) 924-7770 FAX: (434) 982-2137 [3]http://www.evsc.virginia.edu/faculty/people/mann.shtml Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- -- Thomas J. Crowley Nicholas Professor of Earth Systems Science Dept. of Earth and Ocean Sciences Nicholas School of the Environment and Earth Sciences Box 90227 103 Old Chem Building Duke University Durham, NC 27708 tcrowley@duke.edu 919-681-8228 919-684-5833 fax ______________________________________________________________ Professor Michael E. Mann Department of Environmental Sciences, Clark Hall University of Virginia Charlottesville, VA 22903 _______________________________________________________________________ e-mail: mann@virginia.edu Phone: (434) 924-7770 FAX: (434) 982-2137 [4]http://www.evsc.virginia.edu/faculty/people/mann.shtml ______________________________________________________________ Professor Michael E. Mann Department of Environmental Sciences, Clark Hall University of Virginia Charlottesville, VA 22903 _______________________________________________________________________ e-mail: mann@virginia.edu Phone: (434) 924-7770 FAX: (434) 982-2137 [5]http://www.evsc.virginia.edu/faculty/people/mann.shtml References 1. http://www.cru.uea.ac.uk/~timo/ 2. http://www.cru.uea.ac.uk/~timo/sunclock.htm 3. http://www.evsc.virginia.edu/faculty/people/mann.shtml 4. http://www.evsc.virginia.edu/faculty/people/mann.shtml 5. http://www.evsc.virginia.edu/faculty/people/mann.shtml