GIDS-1 TVA Stream Flow Dataset
     

     1.0  General Description
     
          The Tennessee Valley Authority (TVA) stream flow dataset is one
     of three hydrological datasets provided as part of the GEWEX Continental-
     scale International Project (GCIP) Initial Dataset One (GIDS-1). This
     dataset contains stream flow data from 14 TVA stations in the GIDS-1
     area of  interest. The GIDS-1 area is approximately 85W to 106W
     longitude and 30N to 45N latitude. The dataset covers the complete GIDS-
     1 time period from 01 February 1992 through 30 April 1992. 
     
     2.0  Detailed Data Description
     
          The TVA stream flow dataset format contains six metadata
     parameters followed by two data parameters. The metadata parameters
     identify the station and time at which the data values were collected. Each
     record contains a complete day of data or 24 hours. The two data
     parameters (i.e., stage and stream flow) are repeated once for each hour in
     the UTC day (0000 to 2300). Reported stage and stream flow values are
     two hour averages for the preceding two hours. Because the original data
     was bi-hourly, every other hour is set to '-888.88 -888.88' . If an hour's
     values are '-888.88 -888.88', then that hour's values have been averaged
     into the next hour's values. Adding in the '-888.88 -888.88' hours allows
     each data record to begin at 0000 UTC. Conversations and correspondence
     with the TVA indicate that the 0400 local hour on the first day of Daylight
     Savings Time (DST) contains data values averaged over only one hour.
     This hour's data values are set to missing in this dataset.  No additional
     quality control (QC) was performed on this dataset by the Office of Field
     Project Support (OFPS). The table below details the data parameters in
     each record, including a C programming language format description.
     
     Parameters                    Units (C format)
     
     Date of Observation           UTC ('%-8s ')
     Time of Observation           UTC ('%-8s ')
     Date of Observation           Local ('%-8s ')
     Time of Observation           Local (' %-8s ')
     Network Identifier            Abbreviation of platform 
                                   name ('%-10s ')
     Station Identifier            Network Dependent ('%-10s ')
     Stream flow (bi-hourly ave)   Cubic Meters per second (' %8.2f ')
     Stage (bi-hourly ave)         Meters ('%7.2f')
     

     2.1  Data Remarks
     
          TVA stream flow data are bi-hourly averages for the preceding two
     hours. Every other hour in the output shows `-888.88 -888.88' to indicate
     that this hour's values have been averaged into next hour's data values.
     For example, if data is received for hours 0200, 0400, etc., the data for
     hour 0100 have been included in the 0200 hour, data for 0300 have been
     included in the 0400 hour, etc. These alternating `-888.88 -888.88' hours
     were added to the data so that each day record could begin at 0000 UTC.
     
     2.2  Sample Data
     
          The following is a sample record of the TVA stream flow data. 
     Unlike this example, there are no carriage returns in the data. A complete
     day of data per station are presented in each record. See section 2.0 for
     an exact format specification.
     
     92/04/16 00:00:00 92/04/15  19:00:00 TVA        00020460    -888.88
     -888.88     2.18    4.06  -888.88 -888.88     2.15    4.06  -888.88 -888.88 
        2.10    4.05  -888.88 -888.88     2.04    4.04  -888.88 -888.88     2.01 
       4.04  -888.88 -888.88     1.76    4.01  -888.88 -888.88     1.76    4.01
     -888.88 -888.88     1.73    4.01  -888.88 -888.88     1.61    4.00  -888.88
     -888.88     1.59    4.00  -888.88 -888.88     1.56    4.00  -888.88 -888.88 
        1.53    3.99
     
     3.0  Quality Control Processing
     
          No additional quality control (QC) was performed on this dataset
     by the UCAR/Office of Field Project Support (UCAR/OFPS).
     
     4.0  References
     
          For additional station information, refer to the station list
     provided as a seperate dataset in CODIAC.