Data Format Descriptions

Southern Oxidants Study Processed Surface Meteorology

      Information text file for the 1999 Southern Oxidant Study (SOS'99) 
         standard meteorological tower 1-min and 60-min averaged data

                           June 15- July 15, 1999

        National Oceanographic and Atmospheric Administration (NOAA)

                      Earth System Research Laboratory

                         Physical Sciences Division

I. File naming convention

A. 1-min averaged data:
The 1-min averaged data are daily files with a 12-character naming convention
shown as the following:


          SSS: the site 3-letter acronym
          YY: the year 99
          JJJ: the Julian Day
          .01M: the extension indicates the averaging period, 1-min averages.

B. 60-min averaged data:

The 60-min averaged data are monthly files with a 12-character naming
convention shown as the following:


          SSS: the site 3-letter acronym
          YY: the year 99
          MMM: the Month indicated as either JUN, JUL, or AUG.
          .60M: the extension indicates the averaging period, 60-min averages.

II. Sites 

     ETL 10-m met towers were installed at four site locations: Cornelia Fort
Air Park, Dickson, Eagleville, and Gallatin.  At the request of the SOS'99 
Program Director, ETL also provided a Temperature/RH unit at the State of 
Tennessee Department of Health and Environment Laboratory Facility in
Nashville during the last week of the field study.  Following is a list of the
three-letter site identifiers and the site locations:

	Site          Identifier	Lat	Long	Elev (m)			

Cornelia Fort Air Park   CFA		36.19	-86.70	126
Dickson                  DIK		36.25	-87.37	225
Eagleville               EGV		35.73	-86.60	228
Gallatin                 GAL		36.33	-86.40	171
TN. Dept. of Health      DHE		36.22	-86.74	198

III. Data start and end times

CFA  Start: 6/13 Julian Day 164 @ 2100 UTC  End: 7/24* Julian Day 205 @ 1715 UTC
DIK  Start: 6/5  Julian Day 156 @ 1500 UTC  End: 7/31 Julian Day 212 @ 1902 UTC
EGV  Start: 6/6  Julian Day 157@ 1800 UTC   End: 7/16* Julian Day 197 @ 0924 UTC
GAL  Start: 6/10 Julian Day 161 @ 2100 UTC  End: 8/4  Julian Day 216 @ 1401 UTC
DHE  Start: 7/9  Julian Day 190 @ 1900 UTC  End: 8/3  Julian Day 215 @ 0009 UTC

*CFA data set: premature termination due to power/computer failure at the site.
*EGV data set: premature termination due to datalogger battery failure.

IV. Standard meteorological data parameters and write formatting

     Standard data collected at CFA, DIK, EGV, and GAL does not include the soil
temperature profile, heat flux, and soil moisture data also collected at these
sites, nor does it include the Eppley radiation instrument data also collected  at the CFA site.
Standard meteorological data and write format statement are as follows:

1. YY     year*
2. MM     month*
3. DD     day*
4. DJJJ   decimal Julian Day*
5. HHMM   hour, min in UTC*
6. Surface Pressure  (mb)
7. 3-m Air Temperature (aspirated)  (C)*
8. 3-m Air Temperature SD
9. 3-m Air Relative Humidity   (%)*
10. Mixing Ratio  (g/kg)
11. Precipitation rate   (mm/min) or (mm/hr) depending on averaging period 
12. Wind speed- scalar   (m/s)
13. Wind speed-vector    (m/s)
14. Wind direction  (degrees true)
15. Wind direction SD
16. Peak Gust  (m/s)
17. Downwelling solar radiation  (W/m2)
18. Net radiation  (W/m2) 

*** The starred parameters are the parameters included in the DHE data set.

write format statement for the CFA,DIK,EGV, and GAL parameters:


write format statement for the DHE parameters:


V. Flag Convention

1. Pressure          -99.99
2. Temperature       -99.9
3. Temperature SD    -99.999
4. Relative Humidity -99.9
5. Mixing Ratio      -99.99
6. Precipitation     -99.99
7. Wind speeds        -9.9
8. Wind direction    -99.9
9. Wind direction SD -99.999
10. Solar radiation -999.9
11. Net radiation   -999.9

VI. When flags were used and notice to data users

 The flagging procedure for these data is intended to flag extreme outliers and 
miss data only.  The interpretation of 'usable' and 'representative' data are 
otherwise left to the discretion of the individual user.  Instrument spot checks
compared to a designated standard throughout the experiment indicated that all 
instruments were operational within the acceptable standards outlined in the
experiment proposal except for the following:

 The A.I.R. pressure instrument at GAL initially agreed with the designated
standard at the start of the experiment, but compared 3 mb lower than the 
standard at the experiment end. 
 No Flagging was used in this case because the instrument showed smooth tracking
and realistic values.
***Important Notice: Due to a programming error at CFA, the 1-min averaged data
is actually a 1-sec sample of the last second in the minute.  Thus the standard
deviations for temperature and wind direction are flagged for the entire data
set.  Peak gust, and accumulated precipitation were not affected by the program-ming error because these data are not averaged.  The hourly data files from
CFA contain hourly averages of the 60 1-sec samples obtained within the hour.
  True 1-min averages of temperature, humidity, wind speed, and wind direction
are available from the sonic anemometer/thermometer and infrared hygrometer
deployed at CFA.

VII. Instrument accuracy and data quality

 At the commence of the SOS'99 field experiment, all NOAA-installed  
meteorological instruments were either new from the factory or newly 
refurbished and factory re-calibrated.  These instruments were operational
within the factory-determined margin of error specific to the instrument type.
 NOAA-ETL received these data sets near-real time to monitor data continuity.
Instrument spot checks compared to a designated standard at installation and
at experiment-end identified sensor drifts over the one-month period.  All
instruments remained within the factory standard except for the pressure at
GAL which, at the end of the experiment, compared 3 mb lower than the designated
standard.  For more information on calibration certificates or instrument
standards, please refer to section VIII for contacts.  It is very important that
the user review section VI which identifies the programming error at CFA.