# North American Seasonal Precipitation Atlas (NASPA) #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/29372 # Description: # Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/NASPA/naspa2020readme.txt # Description: # # Original_Source_URL: http://drought.memphis.edu/NASPA/ # Description: # # Description/Documentation lines begin with # # Data lines have no # # # Data_Type: Climate Reconstructions # # Dataset_DOI: # # Parameter_Keywords: precipitation #-------------------- # Contribution_Date # Date: 2020-03-31 #-------------------- # File_Last_Modified_Date # Date: 2020-03-31 #-------------------- # Title # Study_Name: North American Seasonal Precipitation Atlas (NASPA) #-------------------- # Investigators # Investigators: Stahle, D.W.; Cook, E.R.; Burnette, D.J.; Torbenson, M.C.A.; Howard, I.M.; Griffin, D.; Villanueva-Diaz, J.; Cook, B.I.; Williams, A.P.; Watson, E.; Sauchyn, D.J.; Pederson, N.; Woodhouse, C.A.; Pederson, G.T.; Meko, D.; Coulthard, B., Crawford, C.J. #-------------------- # Description_Notes_and_Keywords # Description: North American Seasonal Precipitation Atlas (NASPA) is a 500- to 2000-year long gridded (0.5 x 0.5 degree) reconstruction of cool- and warm-season total precipitation and the standardized precipitation index over North America, based on 439 tree-ring chronologies in the cool season (Dec-Apr) and 547 tree-ring chronologies in the warm season (May-Jul). # Provided keywords: total precipitation, standardized precipitation index, North America # # Data files and their contents are as follows: # 1) GPCC_COOL_SPI.nc - These are the instrumental standardized precipitation index data for the cool-season on a 0.5 x 0.5 degree grid in netCDF format. # # 2) GPCC_COOL_TOTALPRECIP.nc - These are the instrumental total precipitation data (units=mm) for the cool-season on a 0.5 x 0.5 degree grid in netCDF format. # # 3) GPCC_WARM_SPI.nc - These are the instrumental standardized precipitation index data for the warm-season on a 0.5 x 0.5 degree grid in netCDF format. # # 4) GPCC_WARM_TOTALPRECIP.nc - These are the instrumental total precipitation data (units=mm) for the warm-season on a 0.5 x 0.5 degree grid in netCDF format. # # 5) NASPA_COOL_CHRONS.CRNS - The 439 signal-free and standardized tree-ring chronologies used to reconstruct the cool-season. # # 6) NASPA_COOL_HEADERS.txt - The 439 site headers for the tree-ring chronologies used to reconstruct the cool-season. # # 7) NASPA_COOL_SPI.nc - These are the grid point reconstructions of the cool-season standardized precipitation index on a 0.5 x 0.5 degree grid in netCDF format. # # 8) NASPA_COOL_SPI.txt - These are the grid point reconstructions of the cool-season standardized precipitation index on a 0.5 x 0.5 degree grid in text format. Data are in space-delimited format, where each row contains values for all grid points in a single year. # # 9) NASPA_COOL_STATS.nc - Calibration and verification statistics for every grid point in the cool-season reconstruction in netCDF format. # Five statisics are reported: CRSQ (calibration period R2), CVRE (calibration period leave-one-out cross-validation reduction of error; essentially the same as Allen's PRESS), VRSQ (verification period square of the Pearson's correlation coefficient), VRE (verification period reduction of error), and VCE (verification period coefficient of efficiency). The calibration period is 1928-1978 and the verification period is 1901-1927. See the Journal of Climate paper for more details on why these periods were chosen and why regions with weak verification may be due to poorer quality instrumentation and not due to poor estimation of by the tree rings. # # 10) NASPA_COOL_STATS.txt - Calibration and verification statistics for every grid point in the cool-season reconstruction in text format. See data file #9 above for calibration and verification details. # # 11) NASPA_COOL_TOTALPRECIP.nc - These are the grid point reconstructions of the cool-season total precipitation (units=mm) on a 0.5 x 0.5 degree grid in netCDF format. # # 12) NASPA_COOL_TOTALPRECIP.txt - These are the grid point reconstructions of the cool-season total precipitation (units=mm) on a 0.5 x 0.5 degree grid in text format. The data are in column form with one reconstruction per column and the grid point number is at the top of each column. Column 1 has the years. # # 13) NASPA_GRID_POINTS.txt - These data are the longitude and latitude pairs that locate the grid point reconstructions. The lon-lat pairs are ordered to agree with the column number above each reconstruction (first pair goes with column one, second pair with column two, and so on). # # 14) NASPA_WARM_CHRONS.CRNS - The 547 signal-free and standardized tree-ring chronologies used to reconstruct the warm-season. # # 15) NASPA_WARM_HEADERS.txt - The 547 site headers for the tree-ring chronologies used to reconstruct the warm-season. # # 16) NASPA_WARM_SPI.nc - These are the grid point reconstructions of the warm-season standardized precipitation index on a 0.5 x 0.5 degree grid in netCDF format. # # 17) NASPA_WARM_SPI.txt - These are the grid point reconstructions of the warm-season standardized precipitation index on a 0.5 x 0.5 degree grid in text format. Data are in space-delimited format, where each row contains values for all grid points in a single year. # # 18) NASPA_WARM_STATS.nc - Calibration and verification statistics for every grid point in the cool-season reconstruction in netCDF format. See data file #9 above for calibration and verification details. # # 19) NASPA_WARM_STATS.txt - Calibration and verification statistics for every grid point in the cool-season reconstruction in text format. See data file #9 above for calibration and verification details. # # 20) NASPA_WARM_TOTALPRECIP.nc - These are the grid point reconstructions of the warm-season total precipitation (units=mm) on a 0.5 x 0.5 degree grid in netCDF format. # # 21) NASPA_WARM_TOTALPRECIP.txt - These are the grid point reconstructions of the warm-season total precipitation (units=mm) on a 0.5 x 0.5 degree grid in text format. The data are in column form with one reconstruction per column and the grid point number is at the top of each column. Column 1 has the years. # # 22) NASPA_WARMpf_SPI.nc - These are the grid point reconstructions of the persistence-free warm-season standardized precipitation index on a 0.5 x 0.5 degree grid in netCDF format. # # 23) NASPA_WARMpf_SPI.txt - These are the grid point reconstructions of the persistence-free warm-season standardized precipitation index on a 0.5 x 0.5 degree grid in text format. Data are in space-delimited format, where each row contains values for all grid points in a single year. # # 24) NASPA_WARMpf_TOTALPRECIP.nc - These are the grid point reconstructions of the persistence-free warm-season total precipitation (units=mm) on a 0.5 x 0.5 degree grid in netCDF format. # # 25) NASPA_WARMpf_TOTALPRECIP.txt - These are the grid point reconstructions of the persistence-free warm-season total precipitation (units=mm) on a 0.5 x 0.5 degree grid in text format. The data are in column form with one reconstruction per column and the grid point number is at the top of each column. Column 1 has the years. # #-------------------- # Publication # Authors: David W. Stahle, Edward R. Cook, Dorian J. Burnette, Max C. A. Torbenson, Ian M. Howard, Daniel Griffin, Jose Villanueva Diaz, Benjamin I. Cook, A. Park Williams, Emma Watson, David J. Sauchyn, Neil Pederson, Connie A. Woodhouse, Gregory T. Pederson, David Meko, Bethany Coulthard, Christopher J. Crawford # Published_Date_or_Year: 2020-04-15 # Published_Title: Dynamics, Variability, and Change in Seasonal Precipitation Reconstructions for North America # Journal_Name: Journal of Climate # Volume: 33 # Edition: # Issue: # Pages: 3173-3195 # Report_Number: # DOI: # Online_Resource: https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-19-0270.1 # Full_Citation: # Abstract: Cool- and warm-season precipitation totals have been reconstructed on a gridded basis for North America using 439 tree-ring chronologies correlated with December–April totals and 547 different chronologies correlated with May–July totals. These discrete seasonal chronologies are not significantly correlated with the alternate season; the December–April reconstructions are skillful over most of the southern and western United States and north-central Mexico, and the May–July estimates have skill over most of the United States, southwestern Canada, and northeastern Mexico. Both the strong continent-wide El Niño–Southern Oscillation (ENSO) signal embedded in the cool-season reconstructions and the Arctic Oscillation signal registered by the warm-season estimates faithfully reproduce the sign, intensity, and spatial patterns of these ocean–atmospheric influences on North American precipitation as recorded with instrumental data. The reconstructions are included in the North American Seasonal Precipitation Atlas (NASPA) and provide insight into decadal droughts and pluvials. They indicate that the sixteenth-century megadrought, the most severe and sustained North American drought of the past 500 years, was the combined result of three distinct seasonal droughts, each bearing unique spatial patterns potentially associated with seasonal forcing from ENSO, the Arctic Oscillation, and the Atlantic multidecadal oscillation. Significant 200–500-yr-long trends toward increased precipitation have been detected in the cool- and warm-season reconstructions for eastern North America. These seasonal precipitation changes appear to be part of the positive moisture trend measured in other paleoclimate proxies for the eastern area that began as a result of natural forcing before the industrial revolution and may have recently been enhanced by anthropogenic climate change. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: AGS-1266014, AGS-1266015, AGS-1301587 #------------------ # Site_Information # Site_Name: North America # Location: Continent>North America # Country: # Northernmost_Latitude: 54.75 # Southernmost_Latitude: 15.25 # Easternmost_Longitude: -58.25 # Westernmost_Longitude: -132.75 # Elevation: meters #------------------ # Data_Collection # Collection_Name: NASPA2020precip # Earliest_Year: 0 # Most_Recent_Year: 2016 # Time_Unit: Year CE # Core_Length: # Notes: #------------------ # Chronology_Information # Chronology: # #---------------- # Variables # # For Additional Help in Describing Variables see: # Guide for Naming Variables Using the PaST Thesaurus- http://www1.ncdc.noaa.gov/pub/data/paleo/templates/Variable_naming_guide.pdf # Thesaurus Terms and Definitions- https://www.ncdc.noaa.gov/paleo-search/cvterms # # variables format: shortname what,material,error,units,seasonality,data_type,detail,method,data_format,additional_information) # ## age_AD age, , ,year Common Era, ,climate reconstructions; instrumental; tree ring, , ,N, ## lat latitude, , ,degree north, ,climate reconstructions; instrumental; tree ring, , ,N, ## lon longitude, , ,degree east, ,climate reconstructions; instrumental; tree ring, , ,N, ## COOL_SPI_obs standardized precipitation index, , ,dimensionless,Dec-Apr,instrumental, , ,N,Global Precipitation Climatology Center Full Dataset ## COOL_precip_obs precipitation, , ,millimeter,Dec-Apr,instrumental, , ,N,Global Precipitation Climatology Center Full Dataset ## WARM_SPI_obs standardized precipitation index, , ,dimensionless,May-Jul,instrumental, , ,N,Global Precipitation Climatology Center Full Dataset ## WARM_precip_obs precipitation, , ,millimeter,May-Jul,instrumental, , ,N,Global Precipitation Climatology Center Full Dataset ## count number of samples, , ,count, ,tree ring, , ,N,for tree ring standardized growth index ## trsgi_rw tree ring standardized growth index, , ,dimensionless, ,tree ring,composited,standard chronology method,N,reconstructed from total ring width ## trsgi_ew tree ring standardized growth index, , ,dimensionless, ,tree ring,composited,standard chronology method,N,reconstructed from earlywood width ## trsgi_lw tree ring standardized growth index, , ,dimensionless, ,tree ring,composited,standard chronology method,N,reconstructed from latewood width ## trsgi_rw_sf tree ring standardized growth index, , ,dimensionless, ,tree ring,composited,signal-free chronology method,N,reconstructed from total ring width ## trsgi_ew_sf tree ring standardized growth index, , ,dimensionless, ,tree ring,composited,signal-free chronology method,N,reconstructed from earlywood width ## trsgi_lw_sf tree ring standardized growth index, , ,dimensionless, ,tree ring,composited,signal-free chronology method,N,reconstructed from latewood width ## COOL_precip precipitation, , ,millimeter,Dec-Apr,climate reconstructions;tree ring, , ,N, ## COOL_SPI standardized precipitation index, , ,dimensionless,Dec-Apr,climate reconstructions;tree ring, , ,N, ## COOL_crsq precipitation, ,calibration coefficient of determination,dimensionless,Dec-Apr,climate reconstructions;tree ring, , ,N, ## COOL_cvre precipitation, ,cross-validation reduction of error,dimensionless,Dec-Apr,climate reconstructions;tree ring, , ,N, ## COOL_vrsq precipitation, ,verification coefficient of determination,dimensionless,Dec-Apr,climate reconstructions;tree ring, , ,N, ## COOL_vre precipitation, ,verification reduction of error,dimensionless,Dec-Apr,climate reconstructions;tree ring, , ,N, ## COOL_vce precipitation, ,verification coefficient of efficiency,dimensionless,Dec-Apr,climate reconstructions;tree ring, , ,N, ## WARM_precip precipitation, , ,millimeter,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_SPI standardized precipitation index, , ,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_crsq precipitation, ,calibration coefficient of determination,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_cvre precipitation, ,cross-validation reduction of error,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_vrsq precipitation, ,verification coefficient of determination,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_vre precipitation, ,verification reduction of error,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_vce precipitation, ,verification coefficient of efficiency,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N, ## WARM_precip_pf precipitation, , ,millimeter,May-Jul,climate reconstructions;tree ring, , ,N,persistence-free ## WARM_SPI_pf standardized precipitation index, , ,dimensionless,May-Jul,climate reconstructions;tree ring, , ,N,persistence-free # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: -99.999 # # Data are presented as a series of files detailed under "Description_Notes_and_Keywords" above.