cc: wigley@ucar.edu date: Mon Nov 22 09:29:09 2004 from: Phil Jones subject: Fwd: Re: K&C (fwd) to: Adrian.Simmons@ecmwf.int, santer1@llnl.gov Adrian and Ben, Roger Pielke did send this to me over the weekend, so he's being honest in one respect. I still think he's reading far too much into NCEP1. The bottom panel of their Fig1 shows both CRU and GHCN (-ERA40) having no difference over the period from the late 1960s. If the obs assimilated before 1967 (even in the US) were improved, the apparent drop before might disappear. Cheers Phil Date: Fri, 19 Nov 2004 18:35:58 -0700 (MST) From: Roger Pielke To: p.jones@uea.ac.uk cc: wigley@cgd.ucar.edu Subject: Re: K&C (fwd) X-UEA-MailScanner-Information: Please contact the ISP for more information X-UEA-MailScanner: Found to be clean Phil- FYI; thank you for sharing your paper. I have circulated the attached to our CCSP Committee with the permission of Eugenia and Ming, and want to also share with you. The conclusion from my own work with the NCEP reanalysis is that it is appropriate for trend assessments if integrated metrics are used (thickness for example), and for regions where the regional trend signal is quite large. We have published on both of this issues. One value-added of reanalyses is that since the winds are monitored independently of the temperatures, they provide information on the horizontal layer averaged temperatures in the mid- and high-latitudes, which helps adjust, to some extent, biases in the temperatures. Also, as we have shown with regional data (e.g. Florida) and others have shown elsewhere (e.g. Andy Pitman for Australia) there is a clear land use change signal on surface temperature. This provides independent evidence that the Kalnay and Cai results should be expected. Roger -- +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Roger A. Pielke, Sr., Professor and State Climatologist 1371 Campus Delivery, Department Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371, Phone: 970-491-8293/Fax: 970-491-3314, Email: pielke@atmos.colostate.edu VISIT OUR WEBSITES AT: [1]http://blue.atmos.colostate.edu/ and [2]http://climate.atmos.colostate.edu ---------- Forwarded message ---------- Date: Fri, 19 Nov 2004 11:04:42 -0700 (MST) From: Roger Pielke To: _NESDIS NCDC CCSP Temp Trends Lead Authors , chris.folland@metoffice.gov.uk, peter.thorne@metoffice.gov.uk Cc: Eugenia Kalnay , Ming Cai Subject: Re: K&C (fwd) Resent-Date: Fri, 19 Nov 2004 11:05:15 -0700 Resent-From: CCSPTempTrendAuthors.NCDC@noaa.gov Hi All I requested to Ming Cai and Eugenia Kalnay that they respond to the comments regarding their work. The response is forwarded to you in this e-mail. This debate, of course, should really take place in the literature. There has been, however, in my view an unfortunate change over time where reviewers who disagree with already published work recommend rejection of subsequent work rather than letting the community view and assess the different perspectives on a science issue. Our report has to make sure it is inclusive, in order to avoid this pitfall. An unbiased discussion of the K&C results, and ways to resolve the disagreement through hypothesis testing, should be included in the appropriate chapters. Roger -- +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Roger A. Pielke, Sr., Professor and State Climatologist 1371 Campus Delivery, Department Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371, Phone: 970-491-8293/Fax: 970-491-3314, Email: pielke@atmos.colostate.edu VISIT OUR WEBSITES AT: [3]http://blue.atmos.colostate.edu/ and [4]http://climate.atmos.colostate.edu ---------- Forwarded message ---------- Date: Fri, 19 Nov 2004 12:16:27 -0500 From: cai To: Roger Pielke Cc: Ming Cai , Y. K. Lim , Eugenia Kalnay Subject: Re: K&C Dear Roger, Attached is the preliminary summary report on our recent work on the estimate of land-use-change climate impact using the reanalysis. Very fortunately, we had secured a one-year funding from NSF starting last August. Despite a short time period, we have already produced sufficient results to confirm the robustness of our original work using different datasets that have the state-of-art quality. Here I just want to add one more comment about Simmons et al. paper. Basically, they claimed that the difference between the ERA40 and CRU is very small and therefore, our method is not applicable if the reanalysis is as good as the ERA40. There are two things that are incorrect in their claims. First of all, if the reanalysis were made to be exactly the same as the observations, by definition, there would be no difference between reanalysis and the surface observations. Since the ERA40 was obtained by directly assimilating the CRU surface observations whereas the NNR didn't use any surface temp. observation, it is natural to expect that the difference between the surface observation and ERA40 is small. Second, Simmons et al. manually reduces the difference between the ERA40 and CRU by setting the mean difference between the ERA40 and CRU from 1987 to 2001 be ZERO. As a result, the difference "LOOKs" very small in recent years. However, the difference from 1961 to 1985 has to be larger (otherwise, they would make an error in their plot). In other words, by doing so, the gap between the ERA40 and CRU appears decreasing in time rather increasing in time as shown in KC and in the new figure 1 in the attached file (which is the same as Simmons et al. paper except we reset the 1960-70 to be zero in order to see how the POSITIVE gap increases in time). If we closely examine their figures, we will see by applying their treatment, the gap between CRU and reanalysis is a NEGATIVE one (e.g., CRU is below ERA40 from 1960 to 1980) and such a NEGATIVE gap decrease in time is equivalent to that the POSITIVE gap increases in time as found in KC from the NNR data (e.g., the CRU becomes more above the ERA40). So Simmons et al's results actually CONFIRM our findings rather discredit our finding. We actually reproduced Simmons et al calculations and confirm that their results are correct (see the second attached figure, which is identical to Fig.1 in our preliminary report except the NEGATIVE gap is used and 1-year running mean was applied as in Simmons et al). But their interpretations are incorrect. I appreciate if you could also forward the email to the CCSP authors. Let me know if you want to me to reply to Tom and CCSP co-authors directly. Regards. Ming The report: The replica of one of the key figures in Simmons et al. On Nov 18, 2004, at 4:53 PM, Roger Pielke wrote: Tom- Since we have not seen the paper, we cannot make any judgements on the robustness of that paper in showing that the Kalnay and Cai work is "flawed". I expect to have a summary by Eugenia and Ming tomorrow, however, which will address the published concerns on their work, and will forward to the Committee. Please forward us a copy of the Simmons et al paper. I also would like a response to my MWR Florida paper where we specifically show the dominant role of documented land use change in peninsular Florida in the 20th century on July-August surface air temperature change. Or Andy Pitman's work who shows a major effect on temperature trends in south-western Australia due to land use change. This work, and others like it, support the conclusions of Kalnay and Cai on a major role of land surface processes on surface temperature trends. How do you reconcile those independent conclusions with the paper you list above? Roger -- +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++ Roger A. Pielke, Sr., Professor and State Climatologist 1371 Campus Delivery, Department Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371, Phone: 970-491-8293/Fax: 970-491-3314, Email: pielke@atmos.colostate.edu VISIT OUR WEBSITES AT: [5]http://blue.atmos.colostate.edu/ and [6]http://climate.atmos.colostate.edu On Thu, 18 Nov 2004, Tom Wigley wrote: Date: Thu, 18 Nov 2004 14:28:16 -0700 From: Tom Wigley To: CCSP Authors Subject: K&C Resent-Date: Thu, 18 Nov 2004 14:28:17 -0700 Resent-From: CCSPTempTrendAuthors.NCDC@noaa.gov Folks, Roger makes the point that there is no comprehensive assessment of this paper. There is ... It is in a paper that has, I believe, been accepted by JGR atmospheres. A.J. Simmons, P.D.Jones, et al. "Comparison of trends and low-frequency variability in CRU, ERA-40 and NCEP/NCAR". I think the conclusion is that the K&C paper *is* flawed. Tom. Ming Cai Associate Professor Department of Meteorology Florida State University, Tallahassee, FL 32036 Email: cai@met.fsu.edu, cai@csit.fsu.edu Phone: (850)-645-1551, FAX: (850)-644-9642 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 ----------------------------------------------------------------------------