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) Environmental Technology Laboratory (ETL) Meteorological and Atmospheric Assessment Division (MAAD) I. File naming convention A. 1-min averaged data: (UTC time stamp at the end of the 1-min average) The 1-min averaged data are daily files with a 12-character naming convention shown as the following: SSSYYJJJ.01M 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: (UTC time stamp at the beginning of the hour average) The 60-min averaged data are monthly files with a 12-character naming convention shown as the following: SSSYYMMM.60M 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* (Please refer to note indicated by &&) 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 of data 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 UTC time stamp for the 1-min averaged data indicates the end of the minute average. && The UTC time stamp for the hour-averaged data indicates the beginning of the hour average. *** The starred parameters are the parameters included in the DHE data set. write format statement for the CFA, DIK, EGV, and GAL parameters: format(3(i2.2,1x),f8.4,1x,i2.2,i2.2,1x,f7.2,1x,f5.1,1x,f7.3,1x,f5.1,1x,2(f6.2,1x),2(f4.1,1x),f5.1, 1x,f7.3,1x,f5.1,1x,2(f6.1,1x)) write format statement for the DHE parameters: format(3(i2.2,1x),f8.4,1x,i2.2,i2.2,1x,2(f5.1,1x)) 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 missing 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 at the beginning and end of the experiment indicated that all instruments were operational within factory standard 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 1-min standard deviations for temperature and wind direction are flagged for the entire data set. Peak gust and accumulated precipitation were also affected by the programming error because these max and totals are taken from a 1-sec sample. 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 in 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 sensor 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. VIII. Contact If there are any questions about or problems concerning these data, please contact: Catherine Russell crussell@etl.noaa.gov 303.497.6905 Phone 303.497.6101 Fax