LGM and Mid-Holocene Pollen-Based Continental Climate Reconstructions Bartlein, P.J; Harrison, S.P.; Brewer, S.; Connor, S.; Davis, B.A.S.; Gajewski, K.J.; Guiot, J.; Harrison-Prentice, T.I.; Henderson, A.K.; Peyron, O.; Prentice, I.C.; Scholze, M.; Seppä, H.; Shuman, B.N.; Sugita, S.; Thompson, R.S.; Viau, A.E.; Williams, J.W.; Wu, H. Bartlein, P.J Harrison, S.P. Brewer, S. Connor, S. Davis, B.A.S. Gajewski, K.J. Guiot, J. Harrison-Prentice, T.I. Henderson, A.K. Peyron, O. Prentice, I.C. Scholze, M. Seppä, H. Shuman, B.N. Sugita, S. Thompson, R.S. Viau, A.E. Williams, J.W. Wu, H. Air Temperature Reconstruction Last Glacial Maximum Other Hydroclimate Reconstruction Precipitation Reconstruction earth science/paleoclimate/climate reconstructions|pollen (actual/potential evapotranspiration,null,null,dimensionless,null,climate reconstructions|pollen,anomalized|averaged,null,N,mean of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (precipitation,null,null,millimeter,annual,climate reconstructions|pollen,anomalized|averaged,null,N,mean of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (t-statistic,null,null,millimeter,annual,climate reconstructions|pollen,averaged,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (actual/potential evapotranspiration,null,one standard error,dimensionless,null,climate reconstructions|pollen,averaged,null,N,mean standard error of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (growing degree days,null,one standard error,kelvin day,annual,climate reconstructions|pollen,averaged,null,N,mean standard error of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (precipitation,null,one standard error,millimeter,annual,climate reconstructions|pollen,averaged,null,N,mean standard error of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (temperature,null,one standard error,degree Celsius,warmest month,climate reconstructions|pollen,averaged,null,N,mean standard error of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (notes,null,null,null,null,climate reconstructions|pollen,null,null,N,significance of the t-statistic) earth science/paleoclimate/climate reconstructions|pollen (temperature,null,one standard error,degree Celsius,coldest month,climate reconstructions|pollen,averaged,null,N,mean standard error of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (longitude,null,null,degree east,null,climate reconstructions|pollen,null,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (growing degree days,null,null,kelvin day,annual,climate reconstructions|pollen,anomalized|averaged,null,N,mean of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (t-statistic,null,null,degree Celsius,annual,climate reconstructions|pollen,averaged,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (number of samples,null,null,count,null,climate reconstructions|pollen,null,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (temperature,null,null,degree Celsius,coldest month,climate reconstructions|pollen,anomalized|averaged,null,N,mean of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (t-statistic,null,null,kelvin day,annual,climate reconstructions|pollen,averaged,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (temperature,null,null,degree Celsius,annual,climate reconstructions|pollen,anomalized|averaged,null,N,mean of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (t-statistic,null,null,degree Celsius,warmest month,climate reconstructions|pollen,averaged,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (latitude,null,null,degree north,null,climate reconstructions|pollen,null,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (t-statistic,null,null,dimensionless,null,climate reconstructions|pollen,averaged,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (t-statistic,null,null,degree Celsius,coldest month,climate reconstructions|pollen,averaged,null,N,null) earth science/paleoclimate/climate reconstructions|pollen (temperature,null,one standard error,degree Celsius,annual,climate reconstructions|pollen,averaged,null,N,mean standard error of the reconstructions that fall within the grid cell) earth science/paleoclimate/climate reconstructions|pollen (temperature,null,null,degree Celsius,warmest month,climate reconstructions|pollen,anomalized|averaged,null,N,mean of the reconstructions that fall within the grid cell) earth science/paleoclimate/reconstructions earth science/paleoclimate/reconstructions (Global>LATITUDE >LONGITUDE ) Subfossil pollen and plant macrofossil data derived from 14C-dated sediment profiles can provide quantitative information on glacial and interglacial climates. The data allow climate variables related to growing season warmth, winter cold, and plant-available moisture to be reconstructed. Continental-scale reconstructions have been made for the mid-Holocene (MH, around 6 ka) and Last Glacial Maximum (LGM, around 21 ka), allowing comparison with palaeoclimate simulations currently being carried out as part of the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change. The synthesis of the available MH and LGM climate reconstructions and their uncertainties, obtained using modern analogue, regression and model-inversion techniques, is presented for four temperature variables and two moisture variables. Reconstructions of the same variables based on surface-pollen assemblages are shown to be accurate and unbiased. Reconstructed LGM and MH climate anomaly patterns are coherent, consistent between variables, and robust with respect to the choice of technique. They support a conceptual model of the controls of Late Quaternary climate change whereby the first-order effects of orbital variations and greenhouse forcing on the seasonal cycle of temperature are predictably modified by responses of the atmospheric circulation and surface energy balance. STUDY NOTES: Continental-scale gridded reconstructions of four temperature and two moisture variables, for the mid-Holocene and Last Glacial Maximum, based on pollen and plant macrofossil data. Reconstructions are presented as 2x2 degree grid cell values, in netCDF or CSV (comma separated values) text files. File names and variables reconstructed are as follows: alpha_delta_06ka: alpha (AE/PE, Actual/Potential Evapotranspiration), 6kyrBP alpha_delta_21ka: alpha (AE/PE, Actual/Potential Evapotranspiration), 21kyrBP coldtemp_delta_06ka: Mean Temperature Anomaly of the coldest month, 6kyrBP coldtemp_delta_21ka: Mean Temperature Anomaly of the coldest month, 21kyrBP gdd5_delta_06ka: Growing Degree Days, above 5C base, Ann Mean, 6kyrBP gdd5_delta_21ka: Growing Degree Days, above 5C base, Ann Mean, 21kyrBP map_delta_06ka: Mean Annual Precipitation, 6kyrBP map_delta_21ka: Mean Annual Precipitation, 21kyrBP mat_delta_06ka: Mean Annual Temperature, 6kyrBP mat_delta_21ka: Mean Annual Temperature, 21kyrBP warmtemp_delta_06ka: Mean Temperature Anomaly of the warmest month, 6kyrBP warmtemp_delta_21ka: Mean Temperature Anomaly of the warmest month, 21kyrBP The CSV files are formatted as follows: Col 1: lat latitude of grid-cell center Col 2: lon longitude of grid-cell center Col 3: varname_anm_mean mean of the reconstructions that fall in the grid cell Col 4: varname_se_mean mean of the standard error of estimates for each reconstruction in the grid cell Col 5: varname_tstat t-statistic = mean anomaly/mean standard error of estimate (varname_anm_mean/varname_se_mean) Col 6: varname_sig significance of the t-statistic, i.e., varname_sig = +/- 1, i.e. = sign(tstat) if abs(tstat) > 2 Col 7: varname_sig_value value of the anm_mean if the t-statistic was significant, i.e. sig_val = anm_mean if sig.ne. Col 8: varname_npts number of reconstructions in the grid cell NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Bartlein, P.J Investigator : Harrison, S.P. Investigator : Brewer, S. Investigator : Connor, S. Investigator : Davis, B.A.S. Investigator : Gajewski, K.J. Investigator : Guiot, J. Investigator : Harrison-Prentice, T.I. Investigator : Henderson, A.K. Investigator : Peyron, O. Investigator : Prentice, I.C. Investigator : Scholze, M. Investigator : Seppä, H. Investigator : Shuman, B.N. Investigator : Sugita, S. Investigator : Thompson, R.S. Investigator : Viau, A.E. Investigator : Williams, J.W. Investigator : Wu, H. 2010-11-17 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/9897 https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/readme-bartlein2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/bartlein2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/readme-bartlein2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/bartlein2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_06ka_ALL_grid_2x2.nc English https://www.ncdc.noaa.gov/paleo/study/9897 https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/readme-bartlein2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/gdd5_delta_06ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/alpha_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/bartlein2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/mat_delta_21ka_ALL_grid_2x2.nc https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/map_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_21ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/warmtemp_delta_06ka_ALL_grid_2x2.csv https://www1.ncdc.noaa.gov/pub/data/paleo/pollen/recons/bartlein2010/coldtemp_delta_06ka_ALL_grid_2x2.nc Bartlein, P.J., S.P. Harrison, S. Brewer, S. Connor, B.A.S. Davis, K. Gajewski, J. Guiot, T.I. Harrison-Prentice, A. Henderson, O. Peyron, I.C. Prentice, M. Scholze, H. Seppa, B. Shuman, S. Sugita, R.S. Thompson, A.E. Viau, J. Williams, and H. Wu2010Pollen-based continental climate reconstructions at 6 and 21 ka: a global synthesisClimate Dynamics10.1007/s00382-010-0904-1 -180 -90 180 90