CEOP/EOP-1 BALTEX Cabauw Hourly Surface Meteorology, Flux, and Radiation Data Set 1.0 Contact Information 1.1 UCAR/JOSS Contact Steven F Williams Data Specialist UCAR/JOSS P.O. BOX 3000 Boulder, CO, USA, 80307-3000 Telephone: 303-497-8987 Facsimile: 303-497-8158 E-Mail Address: sfw@ucar.edu 1.2 Cabauw Contact Name: Dr Fred Bosveld Affiliation: Royal Netherlands Meteorological Institute Address: P.O. Box 201 3730 AE De Bilt The Netherlands Email: bosveld@knmi.nl Telephone: +31 30 2206 787 (direct) +31 30 2206 911 (general) Fax: +31 30 2210 407 2.0 General Description This data set contains the Coordinated Enhanced Observing Period (CEOP) Enhanced Observing Period 1 (EOP-1) Baltic Sea Experiment (BALTEX) Cabauw Mast Hourly Surface Meteorology, Flux, and Radiation Data Set. This data set contains hourly data from a single station for the CEOP EOP-1 time period (01 July 2001 to 30 September 2001). The University Corporation for Atmospheric Research/ Joint Office for Science Support (UCAR/JOSS) did not perform quality control processing on this data set. 3.0 Detailed Data Description 3.1 BALTEX Cabauw Algorithms 3.1.1 Native format data In 1972 at Cabauw (06348) a 213 m high mast was specifically built for meteorological research to establish relations between the state of the atmospheric boundary layer (ABL), land surface conditions and the general weather situation for all seasons. The Cabauw Mast, operated by the Royal Netherlands Meteorological Institute (KNMI), is located in the western part of the Netherlands (51.971 deg. N, 4.927 deg. E) in a polder 0.7 m below average sealevel. This site was chosen because it is rather representative for this part of the Netherlands and because only minor landscape developments were planned in this region. This data set is available on-line in 10-minute native format at http://www.joss.ucar.edu/ghp/ceopdm/ under the link "CEOP EOP-1 Reference Site Data Sets". For a document describing the native format data, see the Documentation provided at the same site. Information on the site can also be found at http://www.knmi.nl/onderzk/reindex.html?atmoond/index.html, the KNMI Atmospheric Research webpage. 3.1.1 CEOP/EOP-1 Hourly Surface Meteorology, Flux, and Radiation format data This CEOP/EOP-1 BALTEX Cabauw Hourly Surface Meteorology, Flux, and Radiation data set was formed by extracting the top of the hour observations from the 10 minute native format data. The data are in UTC time. The U and V wind components were computed from wind speed and direction. Relative Humidity was computed from the dew point and temperature using formulas from Bolton (1980). Specific humidity was computed from the surface pressure and dew point using formulas from Wexler and Wildhack (1963). Net radiation was computed from incoming and outgoing shortwave and longwave radiation. More information regarding this site can be found under the "CEOP Reference Site Station Characteristics" link on the UCAR/JOSS CEOP Data Management page at http://www.joss.ucar.edu/ghp/ceopdm/ . 3.2 Station Information The following is a complete description of the station information provided with this CEOP BALTEX Cabauw data set. The actual station information is given at the end of this section. Table 1 details the station list parameters. The beginning and ending dates for the period of coverage are in Universal Time Coordinated (UTC). The Identification Type field is network dependent and indicates the source of the Identification field. The Occurrence field is an integer value used to indicate co-located stations. Note that when a particular parameter is unknown for a station, either a blank, a question mark, or all 9's will appear in that parameter's position. For a complete list of Country, State, and County values, refer to the document in the references (Section 5.0). Possible platform types and frequency values are listed in Tables 2 and 3, respectively. Note that only those platform types present in the CEOP EOP-1 data have been listed. Table 4 contains the station information for this CEOP BALTEX Cabauw data set. Table 1 Parameter Description --------- ----------- Identification ID in data Identification Type Internal ID number type Latitude Station Latitude Longitude Station Longitude Occurrence Station occurrence Lat/Lon Accuracy Number of digits accuracy in lat/lon values Name Expanded station name Commissioned Flag `(C)' indicates commissioned station, `(N)' indicates station which is NOT commissioned Begin Period of Coverage Beginning date of period of coverage (YYYYMMDD) End Period of Coverage End date of period of coverage (YYYYMMDD) Country Country in which station is located State State code County County code UTC offset Hour Offset from UTC time DST switch 'y' indicates station does switch to Daylight Savings Time (DST). 'n' indicates station does not switch to DST Platform type Collection Platform. See Table 2 Reporting Frequency Frequency of data collection Elevation Station elevation Fixed/Mobile flag Flag indicating if station has fixed location. 'f' indicates a fixed station. 'm' indicates a mobile station Table 2 Platform Type Description ------------- ----------- 264 CEOP Reference Site Platform Table 3 Reporting Frequency ------------------- hourly Table 4 Station Information ------------------- Cabauw 53 51.97100 4.92700 0 3 Cabauw mast (N) 20010701 20010930 NL 99 ??? 0.00 n 264 hourly -1.0 f 3.3 Detailed Format Description The CEOP EOP-1 BALTEX Cabauw Hourly Surface Meteorology, Flux, and Radiation Data Set contains 10 metadata parameters and 22 data parameters. The metadata parameters describe the station location and time at which the data were collected. The time of observation is reported both in Universal Time Coordinated (UTC) Nominal and UTC actual time. Days begin at UTC 0100 and end at UTC 0000 the following day. Note that missing parameter values are indicated by "-999.99". The table below details the data parameters in each record. Parameters Units ---------- ----- Date of Observation UTC Nominal Time of Observation UTC Nominal Date of Observation UTC Actual Time of Observation UTC Actual CSE Identifier Abbreviation of CSE name Reference Site Identifier Abbreviation of Site name Station Identifier Reference Site Dependent Latitude Decimal degrees, South is negative Longitude Decimal degrees, West is negative Station Elevation Meters Station Pressure Hectopascals (mb) Dry Bulb Temperature Celsius Dew Point Celsius Relative Humidity Percent Specific Humidity g/kg Wind Speed m/s Wind Direction Degrees U Wind Component m/s V Wind Component m/s Total Precipitation mm Snow Depth cm Sensible Heat Flux W/m2 Latent Heat Flux W/m2 Incoming Shortwave Radiation W/m2 Outgoing Shortwave Radiation W/m2 Incoming Longwave Radiation W/m2 Outgoing Longwave Radiation W/m2 Net Radiation W/m2 Skin Temperature Celsius CO2 Flux uMoles/m2/s Incoming PAR uMoles/m2/s Outgoing PAR uMoles/m2/s 3.4 Data Remarks This data set contains only the hourly observations for the CEOP EOP-1 time period. This data set is also available on-line in native format at http://www.joss.ucar.edu/ghp/ceopdm/ under the link CEOP EOP-1 Reference Site Data Sets. 4.0 Quality Control Processing UCAR/JOSS performed limited gross limit and visual checks on this data set. No data values have been changed. 5.0 References Bolton, D., 1980: The computation of equivalent potential temperature., Mon. Wea. Rev., 108, pp 1046-1053. Department of Commerce - National Institute of Standards and Technology (NIST), 1985: Federal Information Processing Standards Publication 10-3 Countries, Dependencies, & Areas of Special Sovereignty. Department of Commerce - NIST, Washington, DC. KNMI, cited 2003: Atmospheric Research [Available online at http://www.knmi.nl/onderzk/reindex.html?atmoond/index.html] Wexler, A., and W. A. Wildhack, 1963: Humidity and Moisture. Vol. 3: Fundamentals and Standards. Reinhold Publ. Corp., 562 pp.