BOREAS TF-08 NSA-OJP and SSA-OBS Ceilometer Data

7.3 Data Characteristics

7.3.1 Parameter/Variable

The parameters contained in the data files are:

         Column Name
------------------------------
SITE_NAME
SUB_SITE
DATE_OBS
TIME_OBS
MEAN_CLOUD_COVER
CLOUD_HEIGHT_LOWEST
CLOUD_HEIGHT_SECOND
BACKSCATTER_RANGE_FIRST_LAYER
BACKSCATTER_RANGE_SECOND_LAYER
LIFTING_CONDENSATION_LEVEL
CRTFCN_CODE
REVISION_DATE

7.3.2 Variable Description/Definition

The descriptions of the parameters contained in the data files are:

         Column Name                             Description
------------------------------ ------------------------------------------------
SITE_NAME                      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.
SUB_SITE                       The identifier assigned to the sub-site by BOREAS,
                               in the format GGGGG-IIIII, where GGGGG is the
                               group associated with the sub-site instrument,
                               e.g. HYD06 or STAFF, and IIIII is the identifier
                               for sub-site, often this will refer to an 
                               instrument.
DATE_OBS                       The date on which the data were collected.
TIME_OBS                       The Greenwich Mean Time (GMT) of the start of the 
                               data collection.
MEAN_CLOUD_COVER               The fraction of sky covered by clouds, based on
                               ceilometer reports every minute averaged to a ha
                               lf hourly value.
CLOUD_HEIGHT_LOWEST            The lowest observed cloud base height.  If 
                               multiple layers of clouds are observed, this 
                               is the height of the cloud base of the lower 
                               clouds.
CLOUD_HEIGHT_SECOND            If multiple layers of clouds are observed, this
                               is the height of the cloud base of the second 
                               lowest cloud layer.
BACKSCATTER_RANGE_FIRST_LAYER  The range of backscatter in the first cloud layer
BACKSCATTER_RANGE_SECOND_LAYER The range of backscatter in the second cloud 
                               layer.
LIFTING_CONDENSATION_LEVEL     The surface-based lifting condensation level, 
                               derived from temperature and humidity values 
                               acquired at the 22.68 m level on the flux tower.
CRTFCN_CODE                    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                  The most recent date when the information in the
                               referenced data base table record was revised.

7.3.3 Unit of Measurement

The measurement units for the parameters contained in the data files are:

         Column Name                                Units
------------------------------ ------------------------------------------------
SITE_NAME                      [none]
SUB_SITE                       [none]
DATE_OBS                       [DD-MON-YYYY]
TIME_OBS                       [HHMM GMT]
MEAN_CLOUD_COVER               [fraction]
CLOUD_HEIGHT_LOWEST            [meters]
CLOUD_HEIGHT_SECOND            [meters]
BACKSCATTER_RANGE_FIRST_LAYER  [1000 kilometers^-1][steradians^-1]
BACKSCATTER_RANGE_SECOND_LAYER [1000 kilometers^-1][steradians^-1]
LIFTING_CONDENSATION_LEVEL     [meters]
CRTFCN_CODE                    [none]
REVISION_DATE                  [DD-MON-YYYY]

7.3.4 Data Source

The sources of the parameter values contained in the data files are:

         Column Name                             Data Source
------------------------------ ------------------------------------------------
SITE_NAME                      [Assigned by BORIS.]
SUB_SITE                       [Assigned by BORIS.]
DATE_OBS                       [Supplied by Investigator.]
TIME_OBS                       [Supplied by Investigator.]
MEAN_CLOUD_COVER               [Ceilometer]
CLOUD_HEIGHT_LOWEST            [Ceilometer]
CLOUD_HEIGHT_SECOND            [Ceilometer]
BACKSCATTER_RANGE_FIRST_LAYER  [Ceilometer]
BACKSCATTER_RANGE_SECOND_LAYER [Ceilometer]
LIFTING_CONDENSATION_LEVEL     [psychrometer]
CRTFCN_CODE                    [Assigned by BORIS.]
REVISION_DATE                  [Assigned by BORIS.]

7.3.5  Data Range

The following table gives information about the parameter values found in
the data files.

                     Minimum        Maximum        Missng  Unrel  Below   Data
                     Data           Data           Data    Data   Detect  Not
Column Name          Value          Value          Value   Value  Limit   Cllctd
--------------------------------------------------------------------------------
SITE_NAME            NSA-OJP-FLXTR  SSA-OBS-FLXTR  None    None   None    None
SUB_SITE             9TF08-CEILO    9TF08-CEILO    None    None   None    None
DATE_OBS             31-MAY-1994    10-NOV-1996    None    None   None    None
TIME_OBS             0              2330           None    None   None    None
MEAN_CLOUD_COVER     0              1              -999    None   None    None
CLOUD_HEIGHT_LOWEST  0              7315.2         -999    None   None    None
CLOUD_HEIGHT_SECOND  0              3810           -999    None   None    Blank
BACKSCATTER_RANGE_   0              12600          -999    None   None    Blank
FIRST_LAYER
BACKSCATTER_RANGE_   0              500            -999    None   None    Blank
SECOND_LAYER
LIFTING_CONDENSATION 0              3971.77        -999    None   None    Blank
_LEVEL
CRTFCN_CODE          CPI            CPI            None    None   None    None
REVISION_DATE        17-FEB-1999    17-FEB-1999    None    None   None    None
--------------------------------------------------------------------------------
Minimum Data Value -- The minimum value found in the column.
Maximum Data Value -- The maximum value found in the column.
Missng Data Value  -- The value that indicates missing data. This is used to
                      indicate that an attempt was made to determine the
                      parameter value, but the attempt was unsuccessful.
Unrel Data Value   -- The value that indicates unreliable data.  This is used
                      to indicate an attempt was made to determine the
                      parameter value, but the value was deemed to be
                      unreliable by the analysis personnel.
Below Detect Limit -- The value that indicates parameter values below the
                      instruments detection limits.  This is used to
                      indicate that an attempt was made to determine the
                      parameter value, but the analysis personnel determined
                      that the parameter value was below the detection
                      limit of the instrumentation.
Data Not Cllctd    -- This value indicates that no attempt was made to
                      determine the parameter value.  This usually
                      indicates that BORIS combined several similar but
                      not identical data sets into the same data base table
                      but this particular science team did not
                      measure that parameter.

Blank -- Indicates that blank spaces are used to denote that type of value.
N/A   -- Indicates that the value is not applicable to the respective column.
None  -- Indicates that no values of that sort were found in the column.
--------------------------------------------------------------------------------

7.4 Sample Data Record

SITE_NAME,SUB_SITE,DATE_OBS,TIME_OBS,MEAN_CLOUD_COVER,CLOUD_HEIGHT_LOWEST,
CLOUD_HEIGHT_SECOND,BACKSCATTER_RANGE_FIRST_LAYER,
BACKSCATTER_RANGE_SECOND_LAYER,LIFTING_CONDENSATION_LEVEL,CRTFCN_CODE,
REVISION_DATE
'NSA-OJP-FLXTR','9TF08-CEILO',31-MAY-1994,530,.03,4274.82,,,,-999.0,'CPI',
17-FEB-1999
'NSA-OJP-FLXTR','9TF08-CEILO',31-MAY-1994,600,.03,5257.8,,,,-999.0,'CPI',
17-FEB-1999
