Proxy-Based Pacific SST Reconstructions: Readme file --------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program -------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Proxy-Based Pacific SST Reconstructions LAST UPDATE: 10/2001 (Original Receipt by WDCA Paleo) CONTRIBUTORS: Michael N. Evans, Alexey Kaplan and Mark A. Cane, Laboratory of Tree-Ring Research, University of Arizona, and Lamont-Doherty Earth Observatory of Columbia University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2001-068 SUGGESTED DATA CITATION: Evans, M.N., et al., 2001, Proxy-Based Pacific SST Reconstructions, IGBP PAGES/World Data Center A for Paleoclimatology Data Contribution Series #2001-068. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. FUNDING SOURCE: National Science Foundation/ National Oceanographic and Atmospheric Administration, Earth System History Program, Grant 9809140/GC98-657, USA. ORIGINAL REFERENCES: Evans, M.N., A. Kaplan and M.A. Cane, 2002, Pacific sea surface temperature field reconstruction from coral delta 18O data using reduced space objective analysis, Paleoceanography, v.17, No. 1, February 2002. preprint available from http://www.ltrr.arizona.edu/~mevans/preprints/ Evans, M.N., A. Kaplan, M.A. Cane and R. Villalba, 2001, Globality and Optimality in Climate Field Reconstructions from Proxy Data, in Inter-hemispheric Climate Linkages, V. Markgraf (ed.), Cambridge University Press, Cambridge, UK, pp. 53-72, 2001a. Evans, M.N., A. Kaplan and M.A. Cane, 2000, Intercomparison of coral oxygen isotope data and historical sea surface temperature (SST): Potential for coral-based SST field reconstructions, Paleoceanography, 15, 551--562, 2000. Kaplan, A., M.A. Cane, Y. Kushnir, A.C. Clement, M.B. Blumenthal and B. Rajagopalan, 1998, Analyses of global sea surface temperature 1856-1991, J. Geophys. Res., 103(C9), 18,567-18,589. GEOGRAPHIC REGION: Pacific Ocean, 60S-65N, 110E-65W PERIOD OF RECORD: Pac_ssta_instrum: 1856-1990, Pac_ssta_coral: 1800-1990, Pac_ssta_tree: 1590-1990 LIST OF FILES: readme_evans2001.txt (this file), data.cdf (netCDF binary format, includes all variables) data_cdf.txt (netCDF ASCII output, includes all variables) pac_ssta_coral.txt, pac_ssta_coral_err.txt, pac_ssta_instrum.txt, pac_ssta_tree.txt, pac_ssta_tree_err.txt (columnar ASCII text format). Data format: netCDF and ASCII text at WDC Paleo; also available in a range of formats and graphically from: http://markov.ldgo.columbia.edu:81/expert/(/siberia/mevans/WDCA/2001-068/data.cdf)/readCDF DESCRIPTION: Proxy-Based Pacific SST Reconstructions Date of data generation: September 2001. Latitudes of grid points : 57.5S to 62.5N by 5. N= 25 points Longitudes of grid points : 112.5E to 67.5W by 5. N= 37 points Land and missing ocean areas are designated by the missing value -9999. Variable names: sea surface temperature anomaly (SSTa) and error estimate (err_SSTa). Variable unit: degree Celsius. Data precision: nominally double precision; realistically, considering error estimates (see references), 1-2 decimal places. We have produced three sets of reconstructed Pacific Basin SST field and error estimates, based on three sets of observations. SST anomaly values reconstructed on the basis of proxies are small, and the estimated error values are large. These reconstructions each use limited data sets consisting of a uniform type of proxies (specifically, stable isotopes of oxygen in corals; ring width and density measurements in trees). The reconstructed SST fields are provided (along with the analysis based on the instrumental data) as bases for intercomparison of reconstruction methodologies and proxy types. Such intercomparisons are essential for achieving the ultimate future goal: obtaining the best possible reconstruction based on the most complete data set of the proxies of various kinds. We are grateful to the original proxy data contributors whose submissions to the W-DCA made this project possible. (1) Pac_ssta_instrum: Reduced-space, objective analysis of global, historical, 5-degree by 5-degree gridded, ship-based, monthly sea surface temperature anomalies for January 1856 - December 1991 (Kaplan et al., 1998). The analysis of Kaplan et al. (1998) is itself based on the Global Ocean Surface Temperature Atlas (Bottomley et al., 1990). The data here are contributed as annual average anomalies, based on an April-March year. (e.g. year 1856 is the average anomaly for April 1856 through March 1857.) Monthly global gridded analyses are available from the LDEO Data Catalog: http://ingrid.ldeo.columbia.edu/SOURCES/.KAPLAN/.EXTENDED/ Data source for this reconstruction is the Global Ocean Surface Temperature Atlas (Bottomley, 1990). (2) Pac_ssta_coral: reconstruction of Pacific Basin SST field based on thirteen annually averaged coral-derived oxygen isotope time series, using methods described in Evans et al. 2000, 2001b. Input data are available from the W-DCA for Paleoclimatology: (http://www.ngdc.noaa.gov/paleo/coral). The reconstruction is calibrated and verified using the Pac_ssta_instrum dataset described above. (3) Pac_ssta_tree: reconstruction of Pacific Basin SST field based on fifteen tree-ring proxy indicators, using methods described in Evans et al. 2001a,b. Input data are described in Villalba et al. 2001 and in Evans et al. 2001, and are available upon request from M.N. Evans. The reconstruction is calibrated and verified using the Pac_ssta_instrum dataset described above. Chronostratigraphic information: Coral and tree-ring data age models for input data were assumed from the primary literature describing the data: no attempt was made to adjust age models provided for proxy data by the scientists who contributed the data.