Data Set "FLX01_DERIVED_30MIN" ------------------------------ Revised: March 6, 2001 BOREAS Follow-on FLX-01 NSA-OBS 30-Minute Derived NEE, GEE, and Respiration Data The BOREAS Follow-On FLX-01 team derived NEE, GEE, and Respiration using measured tower CO2 flux measurements taken at the NSA-OBS site. The derived data described here is provided as half-hourly measurements and covers the period from March 1994 through the end of 1998. The derived data described here are available in tablular ASCII files. Acknowledge: Steven Wofsy, Allison Dunn Column Name Units Column Description ----------- ----- ------------------ SITE_NAME [none] The identifier assigned to the site by BOREAS, in the format SSS-TTT-CCCCC, where SSS identifies the portion of the study area: NSA, SSA, REG, TRN, and TTT identifies the cover type for the site, 999 if unknown, and CCCCC is the identifier for site, exactly what it means will vary with site type. DATE_OBS [DD-MON-YY] The date on which the data were collected. TIME_OBS [HHMM GMT] The mid-point of the 30-min data collection period, in Greenwich Mean Time (GMT). RESPIRATION [micromoles] Respiration of CO2 under dark conditions. [meters^-2] [second^-1] NEE [micromoles] The net ecosystem exchange of carbon [meters^-2] measured within the chamber. [second^-1] GEE [micromoles] The gross ecosystem exchange of carbon [meters^-2] measured within the chamber. [second^-1] CRTFCN_CODE [none] The BOREAS certification level of the data. Examples are CPI (Checked by PI), CGR (Certified by Group), PRE (Preliminary), and CPI-??? (CPI but questionable). REVISION_DATE [DD-MON-YY] The most recent date when the information in the referenced data base table record was revised. Data Format ----------- The data file contains numerical and character fields of varying length separated by commas. Character fields are enclosed with single apostrophe marks. There are no spaces between the fields. Each data file on the CD-ROM has four header lines of Hyper-Text Markup Language (HTML) code at the top. When viewed with a Web browser, this code displays header information (data set title, location, date, acknowledgments, etc.) and a series of HTML links to associated data files and related data sets. Line 5 of each data file is a list of the column names, and line 6 and following lines contain the actual data File Names ---------- The different types of files can be told apart by their extensions. The general form of the data file names is Date_Site_Name.csv. The Date_Site part of the name is 22 characters, the Name is 3 characters, and the '.csv' extension is 4 characters (for a total of 30 characters). The formats and meanings of the Date component are: YY-MM-DD : The file only contains data from a particular date YY-MM-00 : The file contains all days of a particular month YY-00-00 : The file contains all days of a particular year ALLDATES : The file contains data over all dates The formats and meanings of the Site component are: MULTIPLESITES : The file contains data over all sites SSS-CCC-TTTTT : The file contains data from a particular site SSS : the BOREAS study area identifier CCC : the abbreviated land cover type at the site TTTTT : the type of site The Name component is a 3-letter identifier for the data set. The '.csv' extension stands for 'comma separated values'.