NOAA_AirCore_data_v20170918
Created by Colm Sweeney (9/18/2017)
This is the current NOAA aircore dataset that includes data targeting the following sites:
- Boulder, CO
- Lamont, OK
- Lauder, NZ
- Sodankyla, Finland
Available files:
Level 1
- Initial_file - description of AirCore launch which includes description of AirCore, Met and mole fraction measurements.
- Met File - AC[launchyyyymmddHHMM]_[AirCoreID]_py_final_met.csv is a comma separated value with the met data gathered during the duration of the flight (see variables below)
- Mole Fraction File - AC[launchyyyymmddHHMM]_[AirCoreID]_py_pic.csv is a comma seperated value with mole fraction data from analysis of air in the aircore (see variables belwo)
Level 2
- Initial_file - description of AirCore launch which includes description of AirCore, Met and mole fraction measurements.
- Final output file - AirCore[AirCoreID]_[launchyyyyddmmHHMM]_v[yyyymmdd].txt final dry mole fraction values of aircore (see description below).


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Final output  Variables:
DateTime (yyyy-mm-dd HH:MM:SS)
sec_frm_midnight - seconds from midnight
Pressure (mb) - atmospheric pressure (mbar)
Alt(m)- altitude (meters)
lat(N)- latitude (degrees north)
lon(E)- longitude (degrees east)
CO2 (ppm) - CO2 mole fraction (ppm)
co2_err (ppm) - CO2 mole fraction uncertainty (ppm)
CH4 (ppb) - CH4 mole fraction (ppb)
ch4_err - CH4 mole fraction uncertainty (ppb)
CO (ppb) - CO mole fraction (ppb)
co_err - CO mole fraction uncertainty (ppb)
T (C) - Atmospheric temperature (C) - Radiosonde (IMET usually)
TH(K) - Atmospheric potential temperature (K) - Radiosonde (IMET usually)
RH (%)- Atmospheric relative humidity (%)- Radiosonde (IMET usually)
AirCoreT(C) - Averge AirCore Temperature during flight (C)
alt_err_co2+(m) - estimated diffusion altitude (m) for CO2 above Alt that is included in the measurement
alt_err_co2-(m) - estimated diffusion altitude (m) for CO2 below Alt that is included in the measurement
alt_err_ch4+(m) - estimated diffusion altitude (m) for CH4 above Alt that is included in the measurement
alt_err_ch4-(m) - estimated diffusion altitude (m) for CH4 below Alt that is included in the measurement
alt_err_co+(m) - estimated diffusion altitude (m) for CO above Alt that is included in the measurement
alt_err_co-(m) - estimated diffusion altitude (m) for CO below Alt that is included in the measurement

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INI Variables:
Cylinders_Header - Column headers for trace gas measured
Fill_Std_Values - Mole fraction value for "fill" gas - gas that AirCore has in it before launch
Cal_Std_Values - Mole fraction value for "cal" gas - gas used to calibrate instrument
Chase_Std_Values - Mole fraction value for "chase" gas - gas that follows sample at bottom of AirCore
Fill_Std_Scale - Scale for "fill" gas 
Cal_Std_Scale - Scale for "cal" gas - gas used to calibrate instrument
Chase_Std_Scale - Scale for "chase" gas - gas that follows sample at bottom of AirCore
Fill_Std_ID - ID of tank used for as the "fill" gas
Cal_Std_ID - ID of tank used for as the "cal" gas
Chase_Std_ID - ID of tank used for as the "chase" gas
Analyzer_ID - ID of analyzers used for analysis of trace gases
Mole_fraction_file_name - Name of data file from mole fraction analysis (see decription below)
Analysis flow rate - cc/min. Approximate flow rate used during analysis
AirCore_ID - AirCore ID (specific ID of AirCore tubing plus fittings)
Met_Sensor_ID - ID of met (RH, T) sensors used
Met_file_name - Name of met data file (see decription below). 
CO_flag - (0 or 1) indicates CO was used as a tracer for mixing.
flip - (0 or 1) indicates whether aircore is being analyzed top (1) first or bottom (0) first
Tot_AirCore_launched - Total aircores balloons launched during a single day (UTC)
Tot_AirCore_Strings - Total AirCore samplers launched during a single day (UTC)
Valve_Close_Delay - delay (minutes) between aircore landing and valve closing 
Min_indx_Cutoff
Max_indx_Cutoff
Home_Institution
AirCore Dimensions:
 - Section number - incremental section in AirCore from top to bottom and includes sample measurement apparatus. 
 - Description - Text description of section.
 - Used_fill - used_fill(1) when being used during sampling 
 - Used_analysis - Used_analysis(1) when being used during analysis phase
 - length - length(m) of section.
 - Diameter - Inner diameter (m) of section
 - Porosity - Fraction of total volume available for airflow
 - CV - Critical flow value of section. 1 suggest no critical flow value

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Met Data Variables:
secs_since_midn_UTC - seconds after midnight 
lat(N)- degrees
lon(E)- degrees
Alt (m)- meters
Pressure (mb) - mbars
T (C)- Temperature, celcius (Radiosonde)
RH (%)- Relative Humidity, percent (Radiosonde)
Tcore1 - AirCore temp1
Tcore2 - AirCore temp1
Tcore3 - AirCore temp1
Tcore4 - AirCore temp1
Tcore5 - AirCore temp1
Flight - Ground(0)/Ascent(1)/Descent(2) 
close - Valve close after landing (1). Not closed (0)
smooth_alt - Smoothed altitude profile
smooth_Pamb - Smoothed pressure profile
smooth_Tamb - Smoothed temperature profile
smooth_Tcoil - Smoothed average aircore temperature profile - Average of most 1-5 temperature sensors in AirCore 
fract_moles_imet - output on flow model indicating the fraction (relative to the landing) of total dry air capture at each altiude during flight
dP_mb - differential pressure (mbar) measure between ambient and closed end of the AirCore

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Mole Fraction Data Variables:
tco2_since_midn_UTC - seconds after midnight (use data of filename as midnight)
CO2(ppm) - CO2 dry mole fraction (umol CO2/mol dry air) 
CH4(ppb) - CH4 dry mole fraction (nmol CH4/mol dry air)
CO (ppb) - CO dry mole fraction (nmol CH4/mol dry air)
AirCore_index - AirCore_index(1) estimated beginning to end of AirCore sample.  AirCore_index(0) when running standards or other AirCores
top_mix_index - top_mix_index(1) marking mixing between "fill" gas and "clean" sample at top of aircore.
bot_mix_index - bot_mix_index(1) marking mixing between "chase" gas and "clean" sample at bottom of aircore sample.