BEACHON Trace Gas Data
Location:  Manitou Experimental Forest, Chemistry Tower
Investigator:  Andrew Turnipseed
Fileaname Format:  NCAR_TraceGas_2010mmdd_V1.txt
		(tab-delimited, ASCI text files)

Sensor(s):  
SO2:  Thermo Environmental Model 43C-TLE
O3:  2B Techonologies, Model 205 dual beam
NO/NOy:  Ecophysics Model CLD-88Y
NO2:  Droplet Technologies Blue Light Converter for NO2 (coupled with NO measurement)
CO2/H2O: Licor Li-6262

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Time Interval:  1 minute averages
(1 sec data available from investigator if needed, turnip@ucar.edu)
Measurement Heights (last column of data):
Inlets at 6 heights:  z=1.8 m, z=5.0 m, z=8.5 m, z=12.0 m, z=17.7 m and z=25.3 m
Time Tag: Mid-point of the 5 min. period.
Missing/invalid data:  -9999
Data below the detection limit (see comment #5 below):  -7777
Data Logging:  Raw signals measured and valves by Campbell CR10 datalogger.  This is then recorded by Labview/laptop.

Comments:  
(1) Measurements are made sequentially for 5 min. at each inlet height.  Profile begins on the 1/2-hour at the 1.8m level.  
    O3, SO2, CO2 and H2O are averaged over the entire period (excluding initial 25 seconds flushing of lines/instruments). For
    N-species (NO, NO2, NOy), these are measured sequentially within each 5 min. period by a single-channel NO analyzer.  
(2) NOy measurements: Sample gas must pass through ~ 33 m of inlet tubing (from each level) before encountering the heated 
    molybdenum NOy converter.  Therefore, it is unlikely that reactive N-species (such as HNO3,N2O5,HONO) are sampled quantitatively.  
    The NOy measurement should include contributions from NOx, PANs and alkyl nitrates.
(3) All instruments are calibrated automatically every 6 hours.  The offset for all instruments are measured simultaneously during
    one 5-min. period, the gains for SO2, NO and CO2 are measured 30 minutes later during a second 5-min. period. These periods are 
    denoted as missing data (-9999) in the current data files. 
(4) The NO2 photolytic converter suffered contamination issues over the weekend of Aug 8-10 and data for NO2 (NOx) was not valid 
    again until Aug. 23rd.  Only NO and NOy are available during this period.
(5) Detection limits on the SO2 and NO instruments were calculated to be 60 pptv and 50 pptv, respectively.  These are in accordance 
    with the manufacturer's specifications for each instrument given our averaging times.  O3, CO2 and H2O were always well above 
    detection limits.

Data Columns:
Column:
1.	Date:mm/dd/2010
2.	hour:minute:sec (midpoint of 5 min. average)
3.	Decimal Day
4.	SO2, ppbv
5.	O3, ppbv
6.	CO2, ppmv
7.	H2O, mmol/mol
8. 	NO, ppbv
9.	NO2, ppbv
10.	NOx (NO+NO2), ppbv
11.	NOy, ppbv
12.	Measurement height on tower