Historical Climate data (1940-2006) for the conterminous United States at the county spatial scale based on PRISM climatology

Metadata:
Identification_Information:
Citation:
Citation_Information:
Originator: Coulson, David P.
Originator: Joyce, Linda A.
Publication_Date: 2010
Title:
Historical Climate data (1940-2006) for the conterminous United States at the county spatial scale based on PRISM climatology
Geospatial_Data_Presentation_Form: tabular digital data
Publication_Information:
Publication_Place: Fort Collins, CO
Publisher: USDA Forest Service, Rocky Mountain Research Station
Online_Linkage: https://doi.org/10.2737/RDS-2010-0010
Description:
Abstract:
Monthly totals of precipitation in millimeters (mm), monthly means of daily maximum air temperature in degrees Celsius (C), and monthly means of daily minimum air temperature (C) were developed at the 5 arc minute grid level for the conterminous United States (US) for the 1940-2006 period. Also, included are computed monthly mean of daily potential evapotranspiration (mm) and mean grid elevation in meters (m). These data were developed from PRISM (Parameter-elevation Regressions on Independent Slopes Model) data at the 2.5 arc minute scale and aggregated to the 5 arc minute grid scale. The county means were computed using a weighted mean of the 5 arc minute grids within the county.
Purpose:
The USDA Forest Service (USFS) produces a periodic assessment of the condition and trends of the Nation's renewable resources as required by the Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974. This RPA Assessment provides a snapshot of current US forest and rangeland conditions and trends on all ownerships, identifies drivers of change, and projects 50 years into the future (//www.fs.fed.us/research/rpa/, accessed 8/16/2009). For 2010 RPA Assessment, an integrated modeling framework is being used in which the potential implications of climate change can be analyzed across some resource areas (Langner in review). The nature of the climate variables needed to address climate change impacts for these resource analyses in the 2010 RPA Assessment were determined to be monthly precipitation and temperature variables at the county level spatial scale and for some resource analyses at the 5 arc minute grid scale.
Supplemental_Information:
Original metadata date was 08/02/2010. Metadata modified on 04/22/2011 to adjust citation to include the addition of a DOI (digital object identifier). Minor metadata updates on 02/20/2013. Metadata modified on 07/22/2015 to update cross-reference citations and other minor updates. Additional minor metadata updates on 12/13/2016 and 04/19/2018.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1940
Ending_Date: 2006
Currentness_Reference:
observed
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Description_of_Geographic_Extent:
The counties falling within conterminous US as defined by ARC shape file fia_survey_unit obtained from Robert J. Huggett, Jr. (see Source Information for more details).
Bounding_Coordinates:
West_Bounding_Coordinate: -124.75
East_Bounding_Coordinate: -66.9167
North_Bounding_Coordinate: 49.5
South_Bounding_Coordinate: 25
Bounding_Altitudes:
Altitude_Minimum: 0
Altitude_Maximum: 3778.25
Altitude_Distance_Units: meters
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: RPA assessment
Theme_Keyword: climate scenario
Theme_Keyword: historical temperature
Theme_Keyword: historical precipitation
Theme_Keyword: historical PET estimates
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: climatologyMeteorologyAtmosphere
Theme:
Theme_Keyword_Thesaurus: National Research & Development Taxonomy
Theme_Keyword: Climate change
Theme_Keyword: Climatology
Theme_Keyword: Climate change effects
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: conterminous United States
Place_Keyword: county level
Access_Constraints: None
Use_Constraints:
These data were collected using funding from the U.S. Government and can be used without additional permissions or fees. If you use these data in a publication, presentation, or other research product please use the citation below when citing the data product:

Coulson, David P.; Joyce, Linda A. 2010. Historical Climate data (1940-2006) for the conterminous United States at the county spatial scale based on PRISM climatology. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. https://doi.org/10.2737/RDS-2010-0010
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Linda Joyce
Contact_Organization: USDA Forest Service, Rocky Mountain Research Station, Human Dimensions Program
Contact_Position: Quantitative Ecologist
Contact_Address:
Address_Type: mailing and physical
Address: 240 West Prospect
City: Fort Collins
State_or_Province: CO
Postal_Code: 80526
Country: USA
Contact_Voice_Telephone: 970-498-2560
Data_Set_Credit:
The authors request that any users of this historical climate data presented, here, also provide appropriate acknowledgments to the PRISM developers.

We wish to acknowledge the use of the PRISM data (//www.prism.oregonstate.edu/) to construct the historical 5 arc minute grid data. The PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate mapping system was developed by Christopher Daly, PRISM Group director.

We also acknowledge the support for this project from the USFS RPA Assessment staff.
Native_Data_Set_Environment:
The files are available as comma delimited ASCII text files (CSV).
Cross_Reference:
Citation_Information:
Originator: Joyce, Linda A.
Originator: Price, David T.
Originator: Coulson, David P.
Originator: McKenney, Daniel W.
Originator: Siltanen, R. Martin
Originator: Papadopol, Pia
Originator: Lawrence, Kevin
Publication_Date: 2014
Title:
Projecting climate change in the United States: A technical document supporting the Forest Service 2010 RPA Assessment
Geospatial_Data_Presentation_Form: document
Series_Information:
Series_Name: Gen. Tech. Rep.
Issue_Identification: RMRS-GTR-320
Publication_Information:
Publication_Place: Fort Collins, CO
Publisher: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station
Other_Citation_Details:
85 p.
Online_Linkage: https://www.fs.usda.gov/treesearch/pubs/45721
Online_Linkage: https://doi.org/10.2737/rmrs-gtr-320
Cross_Reference:
Citation_Information:
Originator: Joyce, Linda A.
Originator: Price, David T.
Originator: McKenney, Daniel W.
Originator: Siltanen, R. Martin
Originator: Papadopol, Pia
Originator: Lawrence, Kevin
Originator: Coulson, David P.
Publication_Date: 2011
Title:
High resolution interpolation of climate scenarios for the conterminous United States and Alaska derived from general circulation model simulations
Geospatial_Data_Presentation_Form: document
Series_Information:
Series_Name: Gen. Tech. Rep.
Issue_Identification: RMRS-GTR-263
Publication_Information:
Publication_Place: Fort Collins, CO
Publisher: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station
Other_Citation_Details:
87 p.
Online_Linkage: https://www.fs.usda.gov/treesearch/pubs/39710
Online_Linkage: https://doi.org/10.2737/rmrs-gtr-263
Cross_Reference:
Citation_Information:
Originator: Langner, Linda L.
Publication_Date: 2012
Title:
Future of America’s Forest and Rangelands: Forest Service 2010 Resources Planning Act Assessment
Geospatial_Data_Presentation_Form: document
Series_Information:
Series_Name: Gen. Tech. Rep.
Issue_Identification: WO-87
Publication_Information:
Publication_Place: Washington, DC
Publisher: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station
Other_Citation_Details:
198 p.
Online_Linkage: https://www.fs.usda.gov/treesearch/pubs/41976
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Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The attribute accuracy for the PRISM data is available for both the temperature and precipitation data as part of this data product download (see: /Documents/Metadata_103yr_HiRes_TempData_for_US.pdf and /Documents/Metadata_103yr_HiRes_TempData_for_US.pdf). For the PRISM data, care should be taken in estimating temperature values or precipitation values at any single point on the map. Temperature or precipitation estimate for each grid cell (2.5 arc minutes) are an average over the entire area of that cell; thus, point temperature or precipitation can be estimated at a spatial precision no better than half the resolution of the cell. This application of PRISM aggregates the values across grid cells and does not violate this concern.
Logical_Consistency_Report:
Completeness_Report:
The county level data includes projections for the conterminous United States where the US boundary is defined by the ARC shape file received from the United States Forest Service Forest Inventory and Analysis group (FIA). The data are available as comma-delimited files where each grid is identified by latitude and longitude. The data set contains 3111 counties with 2,501,244 lines of data, 12 months by 67 years (1940-2006) by 3111 counties.
Lineage:
Methodology:
Methodology_Type: Lab
Methodolgy_Identifier:
Methodolgy_Keyword_Thesaurus:
None
Methodology_Keyword: historical temperature, historical precipitation, historical PET, RPA assessment
Methodology_Description:
The methodology to develop the county level historical dataset involved obtaining the historical PRISM climate data, aggregating to the 5 arc minute grids, and estimating potential evapotranspiration (PET). The steps are described here.

Obtaining the historical climate data:

The PRISM data (//www.prism.oregonstate.edu/) were selected to construct the historical time series for 1940-2006 and to build the 1961-1990 historical baseline from which the future climate scenarios were constructed using change factors developed by Price and others. The PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate mapping system, developed by Christopher Daly, PRISM Group director, is a knowledge-based system that uses point measurements of precipitation, temperature, and other climatic factors to produce continuous, digital grid estimates of monthly, yearly, and event-based climatic parameters (Daly et al. 2002, Gibson et al. 2002). Continuously updated, this unique analytical tool incorporates point data, a digital elevation model, and expert knowledge of complex climatic extremes, including rain shadows, coastal effects, and temperature inversions. We obtained historical climate data (monthly means of daily maximum air temperature, monthly means of daily minimum temperature, and monthly values of precipitation) via download (above site). Data are provided in raster files, where each file contains 1405 columns (longitude) and 621 lines (latitude), resulting in 872,505 grids covering the conterminous United States. Each file represents the month and year of a single climate variable. PRISM grids are 2.5 arc minutes square (1/24 arc degrees) referenced by the southwesterly point corner (left-hand corner) at longitude -125.02083 and latitude 25.0625. All longitude/latitude values represent the southwesterly corner of the grid.

Aggregating the Climate Data to the 5 arc minute grid:

Because the climate scenario data set was developed at the 5 arc minute (1/12 arc degree) scale and PRISM data are at the 2.5 arc minute scale, we aggregated the historical climate data to the 5 arc minute spatial scale.

Comparison of the 5 arc minute grids with PRISM grids:

Data represent: 5 arc minute Grids; PRISM
Number of columns (ncols): 702; 1405
Number of rows (nrows): 294; 621
X corner (xllcorner): -125; -125.02083
Y corner (yllcorner): 25; 25.0625
Cell size equivalence: 1/12 degree; 1/24 degree
No data value: -9999; -9999
Longitude grid coverage bound, West: -125; -125.02083
Longitude grid coverage bound, East: -66.41666667; -66.43749667
Latitude grid coverage bound, North: 49.58333333; 50.97916667
Latitude grid coverage bound, South: 25; 25.0625

The PRISM grid scale is one half that of the climate scenario grids, 2.5 versus 5 arc minutes, as a result there are four PRISM grids per 5 arc minute grid. PRISM grids starting point (southwest corner) is offset by 3.75 degrees north and 1.25 degrees east from the 5 arc minute grids. This has the effect of lining up the longitude/latitude center of 1out of 4 of the PRISM grids with each 5 arc minute grid.

We calculated a weighted mean value for each 5 arc minute grid using the following formula of the PRISM grids overlapping the 5 arc minute grid where one PRISM grid (p5 in the formula) overlaps with the center of the 5 arc minute grid, and portions of 8 other PRISM grids are added to the estimate:

Mean grid value =(0.25*p1+0.5*p2+0.25*p3+0.5*p4+p5+0.5*p6+0.25*p7+0.5*p8+0.25*p9)/4, where p1 is overlapping PRISM grid number 1in the northwest corner, p2 - north center, p3 - northeast corner, p4 - west center, p5 - center, p6 - east center, p7 - southwest corner, p8 - south center, and p9 - southeast corner. In the event an overlapping PRISM grid has missing data the average is a weighted average of those grids with data.

Calculation of Potential Evapotranspiration:

Potential evapotranspiration (PET) was calculated using a modification of Penman's work by Linacre (1977), where
PET=[500Tm/(100-A)+15(T-Td)]/(80-T)mm day-1, the potential evapotranspiration rate for vegetation.
T is the mean monthly temperature in units of degrees Celsius, Tm is the mean monthly temperature adjusted for elevation, h is the elevation in units of meters, Td is the mean monthly dew point temperature in units of degrees Celsius (C), and A is the latitude in degrees.

Tm = T + 0.0006h, where h is the elevation. Linacre provides an alternate for estimating (T-Td) when dew point data are not available. (T-Td) = 0.0023h+0.37T+0.53R+0.35Rann-10.9C. Rann is the difference between the means of the hottest and coldest months. R is mean daily range of temperature.

Rann is calculated from the projected data by the formula Max(T1-T12)-Min(T1-T12). Ti is the mean monthly temperature of the month, where T1= Jan, T2=Feb, ..., T12=Dec.

Mean R is estimated from PRISM data using mean monthly of maximum air temperature and the minimum air temperature from1940-2006. This value is used a surrogate for any given year in the future. The R is calculated for each PRISM grid and then a weighted average calculated for the 5 arc minute grids as describe above.

Note that R = sum((Dmax - Dmin))/n, where R is the monthly average, Dmax is the daily maximum temperature, Dmin is the daily minimum temperature, n is the number of day in the month.

An elevation is obtained from PRISM data which is available at the 2.5 minute grids (1/24 degree) and a weighted mean calculated for the 5 arc minute grid.

This methodology provides an estimate of PET, using only the temperature and latitude values from the climate projections, elevation, latitude, and average mean daily temperature range from PRISM data.

Development of County Level Historical Climate Data:

An overlay file between the 5 arc minute grid and the County boundaries was developed in ArcGIS 9.2. This ultimately resulted in 120,680 grids with historical climate data within the conterminous United States. This resulting database file was imported into SAS. The county means for monthly totals of precipitation, monthly means of daily maximum air temperature, monthly means for daily minimum air temperature and mean daily potential evapotranspiration were calculated using a weighted mean value of the underlying grids within the county.
Methodology_Citation:
Citation_Information:
Originator: Coulson, David P.
Originator: Joyce, Linda A.
Originator: Price, David T.
Originator: McKenney, Daniel W.
Originator: Siltanen, R. Martin
Originator: Papadopol, Pia
Originator: Lawrence, Kevin
Publication_Date: 2010
Title:
Climate Scenarios for the conterminous United States at the 5 arc minute grid spatial scale using SRES scenarios A1B and A2 and PRISM climatology
Geospatial_Data_Presentation_Form: tabular digital data
Publication_Information:
Publication_Place: Fort Collins, CO
Publisher: USDA Forest Service, Rocky Mountain Research Station
Online_Linkage: https://doi.org/10.2737/RDS-2010-0017
Methodology_Citation:
Citation_Information:
Originator: Daly, Christopher
Originator: Gibson, Wayne P.
Originator: Taylor, George H.
Originator: Johnson, Gregory L.
Originator: Pasteris, Phillip
Publication_Date: 2002
Title:
A knowledge-based approach to the statistical mapping of climate
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Climate Research
Issue_Identification: 22: 99-113
Online_Linkage: //www.int-res.com/abstracts/cr/v22/n2/p99-113/
Online_Linkage: https://doi.org/10.3354/cr022099
Methodology_Citation:
Citation_Information:
Originator: Linacre, Edward T.
Publication_Date: 1977
Title:
A simple formula for estimating evaporation rates in various climates using temperature data alone
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Agricultural Meteorology
Issue_Identification: 18: 409-424
Online_Linkage: https://doi.org/10.1016/0002-1571(77)90007-3
Methodology_Citation:
Citation_Information:
Originator: Gibson, Wayne
Originator: Daly, Christopher
Originator: Kittel, Tim
Originator: Nychka, Doug
Originator: Johns, Craig
Originator: Rosenbloom, Nan
Originator: McNab, Alan
Originator: Taylor, George
Publication_Date: 2002
Title:
Development of a 103-year high-resolution climate data set of the conterminous United States
Geospatial_Data_Presentation_Form: conference proceedings
Series_Information:
Series_Name: Proc., 13th AMS Conf. on Applied Climatology, Amer. Meteorological Soc., Portland, OR, May 13-16
Issue_Identification: 181-183
Other_Citation_Details:
Proceedings of the American Meteorological Society
Online_Linkage: https://ams.confex.com/ams/13ac10av/techprogram/programexpanded_99.htm
Source_Information:
Source_Citation:
Citation_Information:
Originator: Christopher Daly (PRISM Group director)
Publication_Date: Unpublished material
Title:
Parameter-elevation Regressions on Independent Slopes Model climate mapping system
Geospatial_Data_Presentation_Form: tabular digital data
Online_Linkage: //www.prism.oregonstate.edu/
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1940
Ending_Date: 2006
Source_Currentness_Reference:
observed
Source_Citation_Abbreviation:
PRISM
Source_Contribution:
Originally, files were obtained from: //www.prism.oregonstate.edu/docs/meta/ppt_103yr.htm and //www.prism.oregonstate.edu/docs/meta/temp_103yr.htm. However, these URLs are no longer valid.

Both of these files were printed to PDF on 6/9/2010 and included in this data product as: /Documents/Metadata_103yr_HiRes_PPTData_for_US.pdf and /Documents/Metadata_103yr_HiRes_TempData_for_US.pdf.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Robert J. Huggett, Jr.
Publication_Date: Unpublished material
Title:
Conterminous US as defined by ARC shape file fia_survey_unit
Geospatial_Data_Presentation_Form: Shapefile Feature Class
Publication_Information:
Publication_Place: PO Box 12254 (mail), 3041 Cornwallis Road (deliveries), Research Triangle Park, NC 27709
Publisher: USFS FIA
Other_Citation_Details:
Tel.: 919-549-4025, Fax: 919-549-4047, e-mail: rhuggett@fs.fed.us
Type_of_Source_Media: DVD
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: Unknown
Ending_Date: Unknown
Source_Currentness_Reference:
observed
Source_Citation_Abbreviation:
Huggett
Source_Contribution:
Data Type: Shapefile Feature Class
Shapefile: fia_survey_unit.shp
Geometry Type: Polygon

Projected Coordinate System: North_America_Albers_Equal_Area_Conic
Projection: Albers
False_Easting: 0.00000000
False_Northing: 0.00000000
Central_Meridian: -96.00000000
Standard_Parallel_1: 20.00000000
Standard_Parallel_2: 60.00000000
Latitude_Of_Origin: 40.00000000
Linear Unit: Meter

Geographic Coordinate System: GCS_North_American_1983
Datum: D_North_American_1983
Prime Meridian: Greenwich
Angular Unit: Degree

Left -178,217598 degrees
Top 71.406235
Right: -66.969271
Bottom: 18.929271
Process_Step:
Process_Description:
No process steps have been described for this data set
Process_Date: Unknown
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Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Each comma-delimited ASCII text file (historical_mth_1940-2000_cty_mean_Dec09.csv and historical_mth_2001-2006_cty_mean_Dec09.csv) contains:

FIPS = State-County Federal Identification Code (//www.census.gov/geo/reference/codes/cou.html)

year = 1940 to 2000, or 2001-2006

month = Values from 1 through 12 represent January through December respectively

ppt_mm = Total monthly precipitation (millimeters)

tmin_C = Monthly averages of daily minimum temperature (degrees Celsius)

tmax_C = Monthly averages of daily maximum temperature (degrees Celsius)

pet_veg_mm = Monthly averages of daily potential evapotranspiration (PET) (millimeters)

avg_elev_m = Average elevation (meters)
Entity_and_Attribute_Detail_Citation:
none provided
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA Forest Service, Research and Development
Contact_Position: Research Data Archivist
Contact_Address:
Address_Type: mailing and physical
Address: 240 West Prospect Road
City: Fort Collins
State_or_Province: CO
Postal_Code: 80526
Contact_Voice_Telephone: see Contact Information
Contact Instructions: This contact information was current as of April 2018. For current information see Contact Us page on: https://doi.org/10.2737/RDS.
Resource_Description: RDS-2010-0010
Distribution_Liability:
Metadata documents have been reviewed for accuracy and completeness. Unless otherwise stated, all data and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. However, neither the author, the Archive, nor any part of the federal government can assure the reliability or suitability of these data for a particular purpose. The act of distribution shall not constitute any such warranty, and no responsibility is assumed for a user's application of these data or related materials.

The metadata, data, or related materials may be updated without notification. If a user believes errors are present in the metadata, data or related materials, please use the information in (1) Identification Information: Point of Contact, (2) Metadata Reference: Metadata Contact, or (3) Distribution Information: Distributor to notify the author or the Archive of the issues.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ASCII
Format_Version_Number: See Format Specification
Format_Specification:
Comma-delimited ASCII text file (CSV)
File_Decompression_Technique: Files zipped with WinZip 14.0
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: https://doi.org/10.2737/RDS-2010-0010
Fees: none
Technical_Prerequisites:
Files are large and not all software packages can view these files. WordPad, which is typically available on a Windows PC, can be used to view these files.
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Metadata_Reference_Information:
Metadata_Date: 20180419
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Linda Joyce
Contact_Organization: USDA Forest Service, Rocky Mountain Research Station, Human Dimensions Program
Contact_Position: Quantitative Ecologist
Contact_Address:
Address_Type: mailing and physical
Address: 240 West Prospect
City: Fort Collins
State_or_Province: Colorado
Postal_Code: 80526
Country: USA
Contact_Voice_Telephone: 970-498-2560
Metadata_Standard_Name: FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001.1-1999
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