gov.noaa.ncdc:C00391 National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce Unknown tabular digital data http://www.ncdc.noaa.gov http://www4.ncdc.noaa.gov/ol/documentlibrary/datasets.html#TD6421 http DSI-6421 Documentation NCDC Dataset Documentation for DSI-6421 information U.S. Enhanced Hourly Wind Station Data is digital data set DSI-6421, archived at the National Climatic Data Center (NCDC). During earlier work at NCDC, it was noted that anemometer elevations at US weather stations (for which metadata related to anemometer height was available) varied widely with time. During the past 60 years, there were up to 12 significant anemometer height changes at some of these stations, and on average there was one change per decade at any station with more than 10 years of record. For example, at Los Angeles International Airport, the anemometer height changed 4 times during the past 60 years, varying from 59 ft to 20 ft, while at Edwards Air Force Base, the anemometer height was changed 10 times and varied from 13 ft to 75 ft. Therefore, the elevation homogenization of the near-surface wind time series is a necessary pre-requisite for any climatological assessments. This was done at NCDC, creating the DSI-6421 data set. Stations were included in DSI-6421 on a year-by-year basis, depending upon the availability of anemometer metadata and the number of observations made during a year. The earliest data was from 1931, with very few stations. The number of stations increased during World War II to about 200, decreased briefly after the war, and increased to about 350 during the period 1948-1972 because most first-order (primary) stations qualified for inclusion. After 1972, as the importance of metadata was more widely recognized, the number of qualified stations rose to near 1000 by 1985, and continued at about that number through year 2000. The formulae used were U10g = Ua log[(10-Hsnod)/z0]/log[(Ha - Hsnod)/z0], and U10s = Ua log[10/z0]/log[(Ha - Hsnod)/z0], where z0 is the surface roughness (a function of the presence of snow cover at the site); Hsnod is the snow depth; Ha is the anemometer height above the ground; Ua is the wind speed at the anemometer height; U10g is the speed at 10 m above the ground; and U10s is the speed at 10 m above the surface. To make a wide range of climatic data available to researchers and the public. Court, A. 1953 J. Franklin. Inst. 256, No.1, 39-55 DeGaetano, A.T., 1998 Theoretical and Applied Climatology 60, 151-162 Golubev, V.S. Bogdanova, E.G. 1996 Proc. of the ACSYS Solid Precipitation Climatology Project Workshop, Reston, VA, USA, 12-15 September 1995, World Meteorol. Organ. WMO/TD No.739 Groisman, P.Ya. Easterling, D.R. Quayle, R.G. Golubev, V.S. Krenke, A.N. Mikhailov, A.Yu. 1996 J. Geophys. Res. 101, 7185-7195 Groisman, P.Ya. Easterling, D.R. Quayle, R.G. Golubev, V.S. 1998 J. Geophys. Res. 103, 6229-6235 Groisman, P.Ya. Knight, R.W. Karl, T.R. 2001 Bull. Amer. Meteorol. Soc. 82, 219-246 Lockhart, T.J. 2000 Proc. of the AMS 12th Conf. On Appl. Climatology, 8-11 May, 2000, Asheville, NC 131-133 McKee, T.B. Doesken, N.J. Davey, Ch. A. Pielke, Sr., R.A. 2000 Fort Collins, Colorado Colorado Climate Center 25 pp. Quayle, R.G. Steadman, R.G. 1998 Weather and Forecasting 13, 1187-1193 data set C00391 ANEMOMETERS WIND VANES WEATHER STATIONS National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce Court, A. 1953: Wind extremes as design factors. J. Franklin. Inst., 256, No.1, 39-55. DeGaetano, A.T., 1998: Identification and implications of biases in U.S. wind observation, archival and summarization methods, Theoretical and Applied Climatology, 60, 151-162. Golubev, V.S., and Bogdanova, E.G. 1996: Accounting of blowing snow events in precipitation measurement in Russia. Proc. of the ACSYS Solid Precipitation Climatology Project Workshop, Reston, VA, USA, 12-15 September 1995, World Meteorol. Organ., WMO/TD No.739. Groisman, P.Ya., D.R. Easterling, R.G. Quayle, V.S. Golubev, A.N. Krenke, and A.Yu. Mikhailov, 1996: Reducing biases in estimates of precipitation over the United States: phase three adjustments. J. Geophys. Res., 101, 7185-7195. Groisman, P.Ya., Easterling, D. R., Quayle, R. G., and Golubev, V.S., 1998: Response to the Comments by D. Yang and B.E. Goodison on the paper by P.Y. Groisman et al. Reducing biases in estimates of precipitation over the United States: Phase 3 adjustments. J. Geophys. Res.,103, 6229-6235. Groisman, P.Ya., R.W. Knight , and T.R. Karl, 2001: Heavy precipitation and high streamflow in the contiguous United States: Trends in the 20th century. Bull. Amer. Meteorol. Soc., 82, 219-246. Lockhart, T.J. 2000: Summary of wind climate continuity with ASOS. Proc. of the AMS 12th Conf. On Appl. Climatology, 8-11 May, 2000, Asheville, NC, 131-133. McKee, T.B., N.J. Doesken, Ch. A. Davey, and R.A. Pielke, Sr., 2000: Climate Data Continuity with ASOS. Report for period April 1996 through June 2000. Colorado Climate Center, Fort Collins, Colorado, 25 pp. Quayle, R.G., and R.G. Steadman, 1998: The Steadman wind chill: An improvement over present scales. Weather and Forecasting, 13, 1187-1193. 19310101 20001231 Ground Condition Complete As Needed -125.0 -65.0 50.0 25.0 ISO 19115 Topic Category climatologyMeteorologyAtmosphere 004 elevation 006 DIF Discipline Keyword Thesaurus Earth Sciences > Atmosphere > Meteorology Earth Sciences > Atmosphere > Climatology Earth Sciences > Atmosphere > Weather GCMD Sciences Keyword Valids EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > SURFACE WINDS EARTH SCIENCE > ATMOSPHERE > ALTITUDE > STATION HEIGHT GCMD Location Valids UNITED STATES OF AMERICA GCMD Location Valids LAND SURFACE WEATHER STATIONS ANEMOMETERS WEATHER STATIONS WIND VANES 1 None None Not provided Unknown Completeness information not available. Unknown Unknown The first group of files contains station metadata: US_1657stns.lst US_1657stns.lst_expanded metadata_NCDC_stn.lst exist-metadata_files anem_elev_inf The original list of stations with hourly information is collected in files US_1657stns.lst and US_1657stns.lst_expanded. The format of these two files is similar except: File US_1657stns.lst contains supplementary text information in lines after 1662 and in positions after 70 that identify composite stations and provides some additional information on how these stations were handled. The first four lines in US_1657stns.lst have clarification information about the column meanings, and the last lines (after line 1662) have comments related to different merging steps that were made to several station files during their pre-processing. File US_1657stns.lst_expanded does not contain this information and has strictly 1657 lines with information (line per station). It (a) has an additional bit of information in the end of each line (blank, or 1) that indicates if the station was in DSI-3280 for at least part of the period (1 stays for yes in this inquiry) (b) shows first and last years with the data for a given station, (c) shows a regional partition of the station within the contiguous U.S. (1 through 9) used in Groisman et al. (2001), and (d) has information about the date of ASOS installation at the station (if any). Variables included are as follows: An index (with values 1 or 2) that characterizes the number of stations that historically had this ID; An extended (6-digit) WMO number used by USAF for station identification; The station name (up to 19 characters); A two character state abbreviation; The longitude and latitude (negative values mean W and S); The station elevation in meters; A 5-digit U.S. National Weather Bureau number (WBAN number if present; otherwise blank); A 6-digit U.S. cooperative station number of the station (if present, otherwise blank); A time zone indicator relative to UTC (EST is -5 UTC, PST is -8); A one-character indicator of the first order station (set to 1, otherwise blank; absent in US_1657stns.lst); The first and the last year with valid data in the archive (absent in US_1657stns.lst); A region number in the following order: Northwest, Missouri River Basin, Upper Mississippi, Northeast, California and Nevada, Southwest, South, Midwest, and Southeast (variable is absent in US_1657stns.lst; map of this partition is shown in Groisman et al. [2001]); A blank if ASOS was not installed at the station (as of July 31, 2001); otherwise first four characters of this string are set to ASOS and the last 8 characters contain the date (year, month, day) of the ASOS commissioning that can be read in format (i4,2i2.2); this string is absent in US_1657stns.lst. Example of file US_1657stns.lst_expanded: 1 722025 FT LAUDERDALE/HOLLY FL -80.15 26.07 7 12849 -5 1972 2000 9 ASOS 19980909 1 722026 HOMESTEAD AFB FL -80.38 25.48 2 12826 -5 1943 2000 9 1 722027 MIAMI BEACH (CGS) FL -80.13 25.77 1 -5 1983 1984 The list of stations with adjusted wind information is provided in exist_metadata_files which is a subset of the US_1657stns.lst_expanded. Variables included are as follows: The extended (six character) WMO station number; The station call letters (if exists, otherwise blank); The station coordinates (lat. and long.); The station elevation (in feet!!!); The station name (up to 35 characters); The true WMO # (if exists; otherwise blank); A 4-character indication if the station became ASOS (or AWOS ) type; The date of the ASOS commissioning (Year, Month, Day); Up to two WBAN numbers assigned to the station (if any). Example: 722313 LIX N 30 20 W 89 49 27 SLIDELL, LA 72233 12916 722314 ARA N 30 02 W 91 53 24 NEW IBERIA, LA ASOS 19980505 03934 File anem_elev_inf was generated from several supplementary files (available upon request). File elev_NCDC_stns contains information about the dates of the anemometer elevation changes for all stations with complete metadata digitized at NCDC. The same structure of the anemometer elevation information files was generated for the 260 U.S. first order stations of contiguous U.S. and Alaska [file elev_1st_order_stns] and for USAF and Navy stations metadata files elev_air_force_stns and elev_navy_stns. Finally, all this elevation information was combined into the file merge_anem_elev_inf.OUT in the order of preference (trustworthiness): First are elev_1st_order_stns, then are elev_NCDC_stns, then elev_navy_stns and elev_air_force_stns. A separate file with duplicate information metadata_files_duplicates was generated and was used to verify the metadata information about the anemometer elevation that comes from different sources. The discrepancies in this information were analyzed and corrected. Variables included are as follows: For each station a line of information contains: The extended (six-character) WMO station number; The number of changes at the station; Up to 30 groups of changes: Date of change: Year, month, day A new anemometer elevation in feet. If the anemometer elevation is not known then it is indicated to be 999.0. If it is known that the AWOS installation was implemented but the anemometer elevation was not reported, then it was assumed to be 10 m (or 33 ft). Complete information about the anemometer elevation at all U.S. ASOS sites was kindly provided by Richard Parry (NOAA/NESDIS). When unknown elevation or day of change were found within the station history record when valid wind speed data exist, the following assumptions were used: (1) If the day of change is not known, it is set to the 15th of the month. (2) During the processing of the metadata file for each station, we assumed that the anemometer elevation prior to the first and after the last record of its changes remain the same as indicated in these first and last records respectively. (3) When adjusting wind speed values for the period with unknown anemometer elevation (999.0), it was assumed to be typical for the year when the change to this unknown elevation was documented: 50 feet (year less than 1951), 20 feet (1959 less than year less than 1995), and 30 feet otherwise. Additional documentation and history is available in file "6421_DSI-6421.doc", a Microsoft Word file that is provided with the data set. Example of file anem_elev_inf: 723125 4 19420915999.0 19510119 30.0 19671115 20.0 19981104 33.0 723126 3 19430715999.0 19440807 39.0 19520415 49.0 723140 6 19340810 86.0 19510426 41.0 19540804 58.0 19601117 20.0 19821116 33.0 19980701 32.8 723143 3 19620924 40.0 19720402 35.0 19900111 33.0 723150 3 19310101 92.0 19640901 20.0 19960601 26.0 None National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce Customer Services Branch Mailing and physical

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Asheville North Carolina 28801-5001 USA 828-271-4800 828-271-4010 828-271-4876 ncdc.metadata@noaa.gov 8:00 - 6:00 Eastern Content Standard for Digital Geospatial Metadata: Extensions for Remote Sensing Metadata FGDC-STD-012-2002 http://www.ngdc.noaa.gov/metadata/extensions/local_extensions.html NGDC Extensions to FGDC Metadata http://www.fgdc.gov/standards/projects/FGDC-standards-projects/csdgm_rs_ex/MetadataRemoteSensingExtens.pdf http://www.fgdc.gov/standards/projects/FGDC-standards-projects/csdgm_rs_ex/remote-sensing-metadata Content Standard for Digital Geospatial Metadata: Extensions for Remote Sensing Metadata, FGDC-STD-012-2002 http://www.eis.noaa.gov/fgdc/fgdcleg.html NOAA Supplemental Information in Description (NOAA legacy extension to FGDC)