date: Wed Apr 16 09:58:52 2008 from: Keith Briffa subject: Re: CRU TS3.0 to: Gerard van der Schrier Morning Gerard the parameter I expect to be best represented in these data is the mean PDSI for summer, in that the trees will grow well in spring and summer in response to warm conditions provided there is sufficient soil water. They will not do well reconstruction temperature or precipitation individually , or even in combination because of lag effects in the association between rain and soil moisture , and over supply of rain will have no affect on growth (or slight negative because of associated summer cold). As for the Gabbi idea we would be better to discuss by phone. I will ring you cheers Keith At 09:41 16/04/2008, you wrote: Keith, Ditto that you are happy to work on the 1000-year oak -based reconstruction - centred on Northwest Europe. We will process the oak data and get back to you on this soon. About these oak recons. - I am thinking of doing perhaps something similar to what Gaby Hegerl did in her J. Clim paper (2007, detection of human influence on a new, validated 1500-yr temp. recon.) Do you think that's possible? What exactly is the parameter you want to reconstruct with these oak data? Cheers, gerard cheers Keith At 10:24 15/04/2008, Gerard van der Schrier wrote: Keith, I've agreed with Ed that I do the PDSI calculations and do some additional quality control tests. Harry will probably keep me updated when he finds more problems with the data. About the Int.J.Clim. paper: I've gone through the remarks you made and which you send me. There are some issues the referees raised, like the infilling of data, which are solved easily. We just have to put more emphasis on the remark we made that infilling is only used for T, the places where P is infilled are flagged as absent and not used in the analysis. I expect that other points are (nearly) as easy. About the Dai paper and other plans with PDSI: the idea is to see if the self-calibrating PDSI is changed dramatically if Penman-Monteith is used rather than Thornthwaite, and i'd like to see a comparison using a complicated and the simple waterbalance model as well. We've discussed this earlier and we don't expect any problems here simply due to the calibrating which probably "adjusts" for any problems with potential evapotranspiration. This should make one paper. The next paper is a global dataset based on the updated CRU data - the rework of Dai's paper. Now that we discuss this topic: I guess we may have problems in regions like the Sahara or Siberia - any ideas yet? We could wait and see how the scPDSI behaves, but is the PDSI a valid index for these regions anyway? Cheers, Gerard Gerard do you wish me to chase this up ? Also can you update me on the Int.J.Clim paper status. Are you considering a rework of the Dai global paper ? Cheers Keith At 08:38 14/04/2008, you wrote: Hi Harry, Sorry to bother you again about the CRU updated data. Ed Cook and myself were wondering about the status of the CRU TS 3.0 data. Is it ready or not yet? We are slightly confused about the status of this update. Some time ago, I received an ftp address for this data and I downloaded the data (both Temp - tx, tg, tn- and Precip). But later, I learned that CRU withdrew support for these data - so I stopped working with these data. Can you tell me where (which continents or which time periods) you suspect most in the dataset I downloaded? (downloaded it at the end of September last year). Or would you advise me not to use the data at all before there is a properly tested dataset? Cheers, Gerard -- ---------------------------------------------------------- Gerard van der Schrier Royal Netherlands Meteorological Institute (KNMI) dept. KS/KA PO Box 201 3730 AE De Bilt The Netherlands schrier@knmi.nl +31-30-2206597 [1]www.knmi.nl/~schrier ---------------------------------------------------------- -- Professor Keith Briffa, Climatic Research Unit University of East Anglia Norwich, NR4 7TJ, U.K. Phone: +44-1603-593909 Fax: +44-1603-507784 [2]http://www.cru.uea.ac.uk/cru/people/briffa/ -- ---------------------------------------------------------- Gerard van der Schrier Royal Netherlands Meteorological Institute (KNMI) dept. KS/KA PO Box 201 3730 AE De Bilt The Netherlands schrier@knmi.nl +31-30-2206597 [3]www.knmi.nl/~schrier ---------------------------------------------------------- -- Professor Keith Briffa, Climatic Research Unit University of East Anglia Norwich, NR4 7TJ, U.K. Phone: +44-1603-593909 Fax: +44-1603-507784 [4]http://www.cru.uea.ac.uk/cru/people/briffa/ -- ---------------------------------------------------------- Gerard van der Schrier Royal Netherlands Meteorological Institute (KNMI) dept. KS/KA PO Box 201 3730 AE De Bilt The Netherlands schrier@knmi.nl +31-30-2206597 [5]www.knmi.nl/~schrier ---------------------------------------------------------- -- Professor Keith Briffa, Climatic Research Unit University of East Anglia Norwich, NR4 7TJ, U.K. Phone: +44-1603-593909 Fax: +44-1603-507784 [6]http://www.cru.uea.ac.uk/cru/people/briffa/