Carbon Cycle Group NOAA/CMDL Tower Program data file formats for station ITN. Contact: Peter Bakwin NOAA ERL R/E/CG1 325 Broadway Boulder, CO 80303 Peter.Bakwin@noaa.gov 303-497-6773 (tel) 303-497-6290 (fax) Tower location: 3 km east of Grifton, North Carolina, USA 35deg 21' 55" N latitude 77deg 23' 38" W longitude tower base altitude = 9 m above sea level local standard time (EST) = GMT - 5 hours References: Bakwin, P.S., C. Zhao, W. Ussler, III, P.P. Tans, and E. Quesnell, Measurements of carbon dioxide on a very tall tower, Tellus, 47B, 535-549, 1995. Bakwin, P.S., P.P. Tans, D.F. Hurst, and C. Zhao, Measurements of carbon dioxide on very tall towers: Results of the NOAA/CMDL program, Tellus, 50B, 401-415, 1998. ******************** itnYEAR.hr.all ******************** Each record (row) is a 30 (starting 950414) or 36 (before 950414) min average of all data. The time is for the middle of that period. There are 23 entries in each record, as below. Col Data Units No data c1 c2 --- -------------------- ------------ -------- --- --- 1 Year GMT 1 4 2 Month GMT 6 7 3 Day GMT 9 10 4 Hour GMT 12 13 5 Minute GMT 15 16 6 CO2, 51 m ppm -999.99 18 24 7 CO2, 123 m ppm -999.99 26 32 8 CO2, 496 m ppm -999.99 34 40 9 Wind Speed, 51 m m/s -99.99 42 47 10 Wind Speed, 123 m m/s -99.99 49 54 11 Wind Speed, 429 m m/s -99.99 56 61 12 Wind Direction, 51 m degrees True -999 63 66 13 Wind Direction, 123 m degrees True -999 68 71 14 Wind Direction, 429 m degrees True -999 73 76 15 Temperature, 51 m degrees C -99.99 78 83 16 Temperature, 123 m degrees C -99.99 85 90 17 Temperature, 429 m degrees C -99.99 92 97 18 Mixing Ratio, 51 m g/kg -99.99 99 104 19 Mixing Ratio, 123 m g/kg -99.99 106 111 20 Mixing Ratio, 429 m g/kg -99.99 113 118 21 Surface Pressure mB -9999.9 120 126 22 PAR microE/m2/s -9999 128 132 23 Rainfall 0.01 inches -999 134 137 --- -------------------- ------------ -------- --- --- c1 c2 refer to the columns spanned by each data value, e.g., execution under UNIX of "cut -c 18-24 itn1995.hr.co2" would extract the data for CO2 at 51 m for 1995. ******************** itnYEAR.day.co2 ******************** Files contain the daily average CO2 mixing ratios for the 51, 123, and 496 m levels. Missing data are assigned -999.99. ******************** itnYEAR.diurnal.co2 ******************** Files contain the monthly average diurnal cycles for CO2. For each day the 24-hour average CO2 mixing ratio at the 496 m level has been subtracted from every observation for that day. Columns are: 1=YEAR, 2=MO, 3=HR, 4= 50%ile, 5= 16%ile, 6= 84%ile, 7= N ( 51 m) # 8= 50%ile, 9= 16%ile, 10= 84%ile, 11= N (123 m) # 12= 50%ile, 13= 16%ile, 14= 84%ile, 15= N (496 m) ******************** itnYEAR.hr.rdn ******************** Files contain the 30 min average radon data. The times give in the file are the middle of the averaging period. The four columns of data are radon concentrations in picoCuries per liter (pCi/L) for the 1, 51, 123, and 496 m levels. Missing data are assigned -9.9999. Notes: The quality of the CO2 data for 123 and 496 m during 950220-950413 was compromised by calibration problems. Use with caution. This file last updated: November 28, 2001