date: Wed, 14 Mar 2001 09:40:46 +0800 from: Scott Rutherford subject: Re: results to: Tim Osborn Answers to questions: > >(1) I'm a little confused: >crua6[/cru/u2/f055/data/paleo/tapio_recons] wc * > 1 560 8961 1400-warm-mxd-nhmean.ascii > 561 565040 9041201 1400-warm-mxd-recongrid.ascii > 144 144271 2308480 verify-warm-mxd-grid.ascii > 1 143 2289 verify-warm-mxd-nhmean.ascii I haven't a clue what happened here but when I gunzipped the files and loaded them into matlab I had the same problem. I replaced the files gzipped them and gunzipped them and they worked ok. If it doesn't work this time I will put them there uncompressed. >(2) The instrumental temperatures I'm using have the centre of each grid >box at (e.g.) 177.5W, 77.5N. Does your 180W, 80N refer to the top-left of >the grid box, or are we really using slightly offset grids? I go the data from http://www.cru.uea.ac.uk/cru/data/temperature/ and based on the information on the web site I took that to be top left corner. >(3) I've just spotted some 'NaN' values in the file - are those the grid >points at which there was never enough observed data to try to infill the >values? This makes it a little difficult to read in - though I guess I can >just do a global edit and change NaN to some missing code. That's correct. There are a few gridpoints that have no data over the calibration period. In the warm season case, there are 6 gridpoints. Do you want me to change the NaN's first? >(4) The values seem to have values as large as 170 or more. What are the >units? Are they standardised anomalies or maybe anomalies in degrees C, >but multiplied by some factor (maybe 100?). What period are they anomalies >from? I assume from the the calibration period (1901-1960), but please >confirm. Yup, the values are all anomalies in °C X 100. > >I'll leave the instrumental data in both of these so you can check >>and make sure we are looking at the same gridpoints. These are all >>northern hemisphere warm-season, April-September. > >(5) Do you mean that those grid boxes that originally had an observed >temperature value in them, at a particular year, still have that value? >Presumably there are no such values in the verification run from 1856-1900 >- I guess that those are *all* infilled from the density only. For the >1400 run, I guess that *all* the values from 1856 onwards are >instrumentally-based (though infilled), except for those few 'Nan' boxes >that couldn't be infilled with either instrumental or MXD data. Can you >confirm all these things? Everything you say is true. The details are: For the verification runs, all the available values from 1998-1901 that were present in the original data are still there. All values from 1856-1900 are imputed from the MXD proxies. For the 1400 reconstruction, all instrumental values from 1856 onward should be there unchanged. Missing instrumental values have been infilled previously using the available data. >(6) Is it possible to also send me the instrumental file from which you >started the verification run (not the infilled version). This is just to >ensure that my observed version is the same (& same coverage) as the one >you're using. I placed on ftp joneswarmnhgrid.ascii which is the original raw data that I started with before filling anything. It is the April-Sept. average of the monthly data. NaN's are missing values, format should be 143 X 1008 same as the others. I hope that clarifies everything. Please let me know if any of this still doesn't make sense or if you have additional questions. In other news, I re-ran the multivariate verification stats using only the orginally available values in the calculations. It turns out it doesn't make too much difference. The verification stats typically are about the same either way, some go up, some go down. Let me know if you need anything else. Regards, Scott -- ______________________________________________ Scott Rutherford University of Virginia University of Rhode Island Environmental Sciences Graduate School of Oceanography Clark Hall South Ferry Road Charlottesville, VA 22903 Narragansett, RI 02882 srutherford@virginia.edu srutherford@gso.uri.edu phone: (804) 924-4669 (401) 874-6599 fax: (804) 982-2137 (401) 874-6160