date: Mon, 21 Apr 2008 08:56:29 +0000 from: Gerard van der Schrier subject: Re: CRU TS3.0 to: t.osborn@uea.ac.uk Hi Tim, I'm slightly confused by the data on the ftp site. Are the .climgen files just unzipped versions of the .tar.gz files? Cheers, Gerard Hi Gerard and Ed, I didn't think that I'd linked my climgen data page from anywhere else (yet) because it isn't ready for public release (yet), though I have forwarded the URL to a few "private" users -- maybe they have added it as a link to their websites? May I ask where you stumbled across it? There have been many problems with CRU TS 3.0 data files so far. I probably wouldn't use anything from Sep 2007 -- though perhaps mean temperature (tmp) is ok; certainly min and max temperature (tmn and tmx) and precipitation (pre) are rubbish and aren't salvageable by avoiding a few regions! If you got vapour pressure and/or wetday counts, then those too were almost completely wrong. However, I'm much more confident about the accuracy of the files on my climgen website, which Harry has re-calculated over recent weeks. At least for data since 1950. There's probably some problems during 1901-1950, though probably fewer that in the CRU TS 2.1 version (though some problems are new!). No doubt there are some problems post 1950 too, but again there were probably more in CRU TS 2.1. Still waiting for vapour pressure and wetdays, and cloud cover updates are some months away. The question is, are they ready for use? Nobody has really used them in anger yet. I'm distributing them to the QUEST-GSI project, who will probably be the first users -- they may find problems that we may correct. If you're willing to use them with the expectation that there may be some updates to correct certain problems (more so before 1950 I'd guess), then I'm happy for this. Harry sounds as if he isn't -- or at least that he wasn't so happy for them to be distributed back in Sep 2007. I've cc'd Phil to see what he thinks -- also Phil may want to say how you might cite the data set (e.g. provisional paper authors/title?). If you do use the data, then the ascii/text files on my climgen website are in a fairly self-explanatory format (time series for each land grid box), though Harry has also produced netCDF files containing grids of monthly data. Cheers Tim Regarding data versions, On Sun, April 20, 2008 10:44 am, Edward Cook wrote: Hi Gerard, Perhaps you already know it, but apparently the precip problem over Bangladesh has been corrected now (Harry indicated that was in progress) as indicated by a website description of Tim Osborn ([1]http:// [2]www.cru.uea.ac.uk/~timo/climgen/data/questgsi/). He even provides an ftp link for the TS 3.0 data files ([3]http://www.cru.uea.ac.uk/~timo/ climgen/data/questgsi/globobs/), perhaps not thinking that I would stumble across it. Anyway, if not already too late, perhaps you will want to use the newest version of the TS 3.0 precip data to generate the global scPDSI data. Cheers, Ed ================================== Dr. Edward R. Cook Doherty Senior Scholar and Director, Tree-Ring Laboratory Lamont-Doherty Earth Observatory Palisades, New York 10964 USA Email: [4]drdendro@ldeo.columbia.edu Phone: 845-365-8618 Fax: 845-365-8152 ================================== On Apr 15, 2008, at 1:18 PM, Gerard van der Schrier wrote: Hi Ed, Given Harry's reply, shall I just use the data I have (version of September 2007), and run some quality control checks? Cheers, Gerard Hi Gerard, On 14 Apr 2008, at 8:38, Gerard van der Schrier 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. Sorry about that. If it was up to me, there would be no confusion because nobody would have seen it at all.. but in real life there are shifting priorities.. 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? I *think* temperature is OK. Precip has a few glitches, (which I've been investigating over the past two weeks), the major one is Bangladesh in the 1990s. Here, updates were added to the database a year or two back but were 10x too low.. I've now found and corrected that. Precip *currently* being regernerated (as I type!). So - use Temp, and Precip but not Bangladesh. Or anywhere else that looks odd when you examine it ;-) Cheers Harry Cheers, Gerard -- ---------------------------------------------------------- Gerard van der Schrier Royal Netherlands Meteorological Institute (KNMI) dept. KS/KA PO Box 201 3730 AE De Bilt The Netherlands [5]schrier@knmi.nl +31-30-2206597 [6]www.knmi.nl/~schrier ---------------------------------------------------------- Ian "Harry" Harris Climatic Research Unit School of Environmental Sciences University of East Anglia Norwich NR4 7TJ United Kingdom -- ---------------------------------------------------------- Gerard van der Schrier Royal Netherlands Meteorological Institute (KNMI) dept. KS/KA PO Box 201 3730 AE De Bilt The Netherlands [7]schrier@knmi.nl +31-30-2206597 [8]www.knmi.nl/~schrier ---------------------------------------------------------- -- ---------------------------------------------------------- Gerard van der Schrier Royal Netherlands Meteorological Institute (KNMI) dept. KS/KA PO Box 201 3730 AE De Bilt The Netherlands [9]schrier@knmi.nl +31-30-2206597 [10]www.knmi.nl/~schrier ----------------------------------------------------------