Information Text File for the 2000 Texas Air Quality Study (TEXAQS'00) Standard Meteorological Tower 1-min/5-min and 60-min Averaged Data August 14 - September 18, 2000 National Oceanographic and Atmospheric Administration (NOAA) Environmental Technology Laboratory (ETL) Weather and Climate Applications Division I. File naming convention A. 1-min averaged data: (UTC time stamp at the end of the 1-min/5-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 00 JJJ: the Julian Day .01M: the extension indicates the averaging period, 1-min averages. .05M: the extension indicates the averaging period, 5-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 00 MMM: the Month indicated as either AUG or SEP. .60M: the extension indicates the averaging period, 60-min averages. II. Sites ETL slow-response meteorological instruments were installed at three site locations: La Porte, Downtown Houston, and the La Porte water tower. Following is a Table of the site: three-letter identifier, location, and elevation: Site Identifier Latitude Longitude Elev. (m MSL) Houston HTN 29.769 -95.359 13 La Porte LPE 29.668 -96.069 8 LP H20 Tower LWT 29.683 -95.077 47 Table 1. Site three-letter identifier, location, and elevation. III. Data start and end times HTN Start: 8/17 Julian Day 230 @ 0 UTC End: 9/18 Julian Day 262 @ 1828 UTC. LPE Start: 8/14 Julian Day 227 @ 0 UTC End: 9/18 Julian Day 262 @ 2359 UTC. LWT Start: 8/15 Julian Day 228 @ 0 UTC End: 9/18 Julian Day 262 @ 2359 UTC. IV. Standard meteorological data parameters and write formatting Standard data collected at LPE does not include the soil temperature profile, heat flux, soil moisture, and Eppley radiation data also collected at this site. Standard meteorological data and write format statement are as follows: 1. YY year* 2. MM month* 3. DD day* 4. JJJ Julian Day* 5. MI month index* 6. HHMM hour, min in UTC* (Please refer to note indicated by &&) 7. Surface Pressure (mb) 8. 2-m Air Temperature (aspirated)(C)* 9. 10-m Air Temperature (aspirated)(C) !!!!Not included at HTN, LPE, or LWT. 10. 2-m Air Relative Humidity (%)* 11. 10-m Air Relative Humidity (%) !!!!Not included at HTN, LPE, or LWT. 12. Wind speed-scalar (m/s) 13. Wind speed-vector (m/s) 14. Wind direction (degrees true) 15. Wind direction SD 16. Down-welling solar radiation (W/m2) 17. Net radiation (W/m2) 18. Mixing Ratio (g/kg) 19. Precipitation rate (mm/min) or (mm/hr) depending on averaging period of data 20. Peak Gust (m/s) && The UTC time stamp for the 1-min/5-min averaged data indicates the end of the one or five minute average. HTN and LPE are 1-min averaged data, LWT is 5-min averaged data. The sampling resolution for the 1-min averaged data is once per second, and once every 5 seconds for the 5-min averaged data. && 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 LWT data set. The temperature and relative humidity are not taken at 2-m but at an elevation of 39.2431 m above the ground. The write format statement for the HTN, LPE, and LWT parameters: Format: (3(i2.2,1x),i3.3,1x,i5.5,1x,i2.2,i2.2,1x,14(f9.3,1x)) This standard format includes 10-m temperature and relative humidity data that do not apply to the TEXAQS 2000 study. These parameters are flagged with the standard flag listed in section V. V. Flag Convention: -9999.999 VI. Flag implementation 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 is 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 and within factory standard except for the following: NOTICE #1: The Vaisala pressure instrument at LPE. Usable pressure data are from (8/14/00) JD 227 @ 1835 through (8/21/00) JD 234 @ 1925. After this date the data are flagged. NOTICE #2: The mixing ratio at LPE are calculated with the pressure data from HTN during the period after the LPE pressure sensor failed (JD 234 @ 1925 UTC until the end of the experiment). The LPE mixing ratio data during the last few hours of the experiment (JD 262 @ 1829 - 2359 UTC) are flagged because the HTN data collection ended at 1829 UTC and the pressure data were not available for the mixing ratio calculation. NOTICE #3: During a 7-day period at LPE (JD 245-251), due to extremely high temperatures the data logger for the slow met data failed to sustain operations throughout the nighttime. The draw on the batteries was enough to terminate collection until the solar panel could recharge the batteries again to an optimal level for data collection. Missing partial or entire hours include the following: JD 245 hours 13-15 UTC JD 246 hours 8-21 UTC JD 247 hours 0-21 UTC JD 248 hours 0-20 UTC JD 249 hours 1-18 UTC JD 250 hours 1-15 UTC JD 251 hours 5-22 UTC VII. Instrument accuracy and data quality At the start of the TEXAQS'00 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 the end of the experiment identified one sensor drift over the one-month period, the pressure sensor at the LPE site. All other instruments remained within the factory standard. For more information on calibration certificates or instrument standards, please refer to section VIII for contacts. VIII. Contact If there are any questions about or problems concerning these data, please contact: Allen White Allen.White@noaa.gov 303.497.5155 Phone 303.497.6101 Fax