cc: Chris Folland date: Fri Oct 15 11:04:40 2004 from: Phil Jones subject: Re: IPCC Chapter3 to: "Thorne, Peter" , "Parker, David (Met Office)" Peter, I've just sent an email to David about this. Maybe if I send you the email that Kevin send to Per Kallberg at ECMWF, you'll see what should be in the box on Reanalyses and their use as climate records. Getting all these bits of text pieced together will be a challenge and it is likely we will not get it right at the first draft. There are 3 other meetings to either completely rewrite or more hopefully fine tune the zeroth order draft. Cheers Phil Hi Per The section you were asked to help on is an appendix Box: maybe half or up to 1 printed page of text in IPCC format or order 1 page single spaced 12 point font on A4 plus small figure. The appendix is about techniques, measurement systems etc. This box should be about reanalyses and and the challenges of creating a homogeneous and continuous climate record. Recall this is for IPCC with a focus on long-term change. So my thoughts on this would be to summarize quickly the observing system and how it changes over time, and its quality. The bias corrections for satellites should be dealt with and how well you think it turned out. We might be able to add a small figure (like the one of all the satellites as fn of time?). The bottom line should be a clear assessment of what the reanalyses can be used for (variability?) and what they can not (trends, decadal?). This is an opportunity to both highlight the reanalyses with a realistic assessment of them for many people, and also advocate for the next steps. This is in contrast to the request I earlier sent to Adrian which was really to exploit the reanalyses to the extent possible and say something about the climate record itself. I'll follow up on that separately. At 10:41 15/10/2004, Thorne, Peter wrote: David (cc Chris, Phil), I still think this is fundamentally a wrong headed decision. We are not just talking about MSU here, but general principles of trying to create CDRs from raw data that has been maintained with operational rather than climate monitoring principles at the heart of it. This applies to satellites as equally as to radiosondes. In fact in satellites it is easier to understand as there are less d.o.f. in the choices of raw data and yet we still get a huge range of results. I maintain that having a box for the raobs but not for satellites brings an Animal Farm mentality to the report: "All UA obs are equal, but some are more equal than others" could be a very obvious (and dangerous) take home, unless I am alone in being as suspect of satellites as raobs, which I hope I'm not. I argue we take one of the following options: 1. fold the raobs box into the reanalysis one 2. set up a separate box for satellite obs 3. expand the remit on my box to UA climate and not limit ourselves solely to raobs there which I'd be happy to do. That would require a bit more space, but not a huge amount. Peter On Fri, 2004-10-15 at 10:22, Parker, David (Met Office) wrote: > Kevin > > Thanks. > > Maybe the Reanalysis box should be entitled "Changes in Satellite and > other Observing Systems and their impacts of reanalyses" to make it > clearer. > > Jim Renwick has responded with an invite to Chris Folland. Our email > addresses have changed from metoffice.com to metoffice.gov.uk and the > change could, conceivably, have caused a problem. > > Regards > > David > > > > > On Thu, 2004-10-14 at 17:56, Kevin Trenberth wrote: > > Hi David > > I am thinking that the box on "Changes in observing system impacts on > > reanalyses" will deal with inhomogeneities in satellite data and other > > data, and so I am less inclined to focus on this issue just for the > > MSU. Anyway that was the thinking. We can see how it works out. > > > > I will follow up with Jim: I have to say I have not heard from him since > > Trieste, so I have been assuming he has been doing as we requested. But > > maybe not. > > > > Dian Siedel was replaced in both places by Melissa Free. That should be > > on the revised annotated outline and on the updated list of CAs. > > Melissa is at the same organization. > > Kevin > > > > Parker, David (Met Office) wrote: > > > > >Kevin > > > > > >We have just had an internal meeting on our contributions to IPCC and > > >the following were noted: > > > > > >The outline chapter has a box on adjustments to homogenize radiosondes, > > >allocated to Peter Thorne. He comments that there should be one also on > > >adjustments to homogenize satellite retrievals...otherwise we give the > > >impression that while radiosondes have problems, satellite data are > > >perfect! Could we ask Carl Mears to write a box? > > > > > > > > >Some invitations from LAs have not yet been received, e.g. Chris Folland > > >hasn't had one from Jim Renwick on atmospheric circulation. > > > > > >Have we found a replacement for Dian Seidel on 3.4.2.1 (radiosonde > > >humidity)? > > > > > >Thanks for your efforts! > > > > > >David > > > > > > > > > > > > > > > -- Peter Thorne Climate Research Scientist Hadley Centre for climate prediction and research Met Office, FitzRoy Road, Exeter, EX1 3PB Tel:+44 1392 886552 Fax:+44 1392 885681 [1]http://www.hadobs.org 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 ----------------------------------------------------------------------------