CALCULATING CLIMATE FROM ANALOGS |
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The output file from the NAPD run "napd.out" contains meta data of the location and publication for each modern analog. If the meta data for each analog (MOD5_0454, MOD5_1660, etc.) included contemporary climate values, they could be used to estimate past climate for fossil samples. (The last two variables of the CLIMAP meta data are Sea Surface Temperatures) |
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The file SURFWUS.TXT contains 1363 contemporary pollen samples from Western North America (Davis, 1995). The samples from tropical Mexico have been removed from the file linked to below, and the variable names have been changed to match NAPD 70 protocol. (You still should check the names for constancy, however.) File SURFMETA.TXT contains the meta data for SURFWUS.TXT including mean annual temperature (oC) and average precipitation (mm) for each analog. File SURFRULE.TXT converts the counts to proportions. File SURFRUN.TXT is the Run Description. Create a new subdirectory named "surf" and download these four text files by opening them with your browser, and then using the browser's "save as" function to save them to the "surf" subdirectory. SURFWUS.TXT SURFMETA.TXT SURFRULE.TXT SURFRUN.TXT |
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Download the "Tilia 2.0 File" for "Montezuma Well" from the NGDC site and save it in the "surf" directory as "montezuma.txt". Change the first line of "montezuma.txt" from # GPD ASCII Formatto # NAPD ASCII FormatBefore saving "montezuma.txt", open "surfwus.txt" using another instance of WORDPAD, or NOTEPAD, and change any names (in "montezuma.txt") that do not match (for example, Chenopodiaceae). Save "montezuma.txt" and save or just close "surfwus.txt". |
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Copy "analog.exe" and "napdrule.txt" from the "napd" subdirectory to the "surf" subdirectory, which should now contain the files: analog.exe montezuma.txt napdrule.txt surfmeta.txt surfrule.txt surfrun.txt surfwus.txt |
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Open a DOS window, move to the "surf" subdirectory, and run the ANALOG program by typing at the DOS prompt analog surfrun.txt |
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Open the file "surface.out" with WORDPAD. The first 10 rows (for the Montezuma Well sample at 0 cm) should look like this Sample ID Rank Analog ID Distance Analog Latt Longit pCm tCA ElvM Vegt 0, , 0 0 CJHE22 0.010060 CJHE22 46.95 121.77 1042 12 530 NWXF 0, , 0 1 ARCH18 0.019261 ARCH18 34.00 118.00 350 19 69 CAST 0, , 0 2 CJHE18 0.021047 CJHE18 46.95 121.77 1282 10 820 NWMF 0, , 0 3 WORE16 0.042908 WORE16 44.50 123.50 928 13 311 NWMF 0, , 0 4 WORE15 0.048011 WORE15 44.50 123.50 833 13 333 NWMF 0, , 0 5 ARCH14 0.048661 ARCH14 37.00 119.00 360 19 205 CAST 0, , 0 6 CJHE14 0.059942 CJHE14 46.95 121.77 1497 8 1175 NWMF 0, , 0 7 CJHE16 0.064078 CJHE16 46.95 121.77 1427 9 1060 NWMF 0, , 0 8 CJHE24 0.066871 CJHE24 46.95 121.77 935 13 295 NWXF 0, , 0 9 WORE08 0.069000 WORE08 44.50 123.50 956 12 355 NWMF |
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All of the dissimilarity values are low. What is the average temperature for the 10 analogs? (12 + 19 + 10 .... /10 = 12.8 oC) the average precipitation is 961.0 mm. Other statistics, such as standard deviation, can be calculated for the climate analogs. Because this is a tab-delimited file, you can cut and paste it into EXCEL to simplify these calculations. For this (ANALOG) exercise, print out the analogs for the first five samples with the average Temperature and Precipitation calculated for each sample. Hand these in. |
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