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R/V Ronald H. Brown Data Info

| Time Parameters | Ship Parameters | Chemical Species | Aerosols | Radiation |

File prefixes from data download are listed below. The file contents are specified and the measurement is described briefly. For more details, see the header of the data file.

Time parameters

Time: 1 Minute averages continuously throughout mission. Start_UTC is the time standard.
Most of the measurements use this time base. Here are the exceptions.
Hg: reported every second.
VOCSsGCMSch1: GC_Start_UTC / GC_Stop_UTC 5 minute measurement every half hour
VOCSsGCMSch2: GC_Start_UTC / GC_Stop_UTC 5 minute measurement every half hour

Ship Parameters

ShipMet

Ship Meteorological Parameters measured with various sensors.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
DewPt_C: Dew Point Temperature (C)
WindDir: Wind Direction (deg)
WindSpd: Wind Speed (m/s)

ShipMis

Ship Miscellaneous Parameters measured with various sensors.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
RelWindDir: Relative Wind Direction (deg)
RelWindSpd: Relative Wind Speed (m/s)
SZA_deg: Solar Zenith Angle (deg)

ShipPos

Ship Position Parameters measured by GPS
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
GpsLat: GPS Latitude (deg)
GpsLon: GPS Longitude (deg)

Chemical Species

CO

Carbon monoxide measured using Vacuum-UV resonance fluorescence.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
CO_ppbv: Carbon Monoxide (ppbv)

CO2

Carbon Dioxide measured using non-dispersive IR absorbance.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
CO2_ppmv: Carbon Dioxide (ppmv)

H2O

Water vapor measured using Nondispersive IR.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
H2O_ppth: Water (ppth)

HCHO

Formaldehyde measured using DOE QCL Instrument Dual Channel 1765 cm-1 and 965->945 cm-1.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
HCHO_ppbv: HCHO (ppbv)
HCOOH_ppbv: HCOOH (ppbv)
C2H4_ppbv: C2H4 (ppbv)
NH3_Uncorrected_ppbv: Uncorrected NH3 (ppbv)

Hg

Gas-phase mercury measured using a modified Lumex RA-915+ mercury analyzer.
Time: 1 second data.
Reported parameter names and units:
Hg_ng_m3: Mercury (ng/m3)
Hg_ng_m3_1sigma: Mercury 1 sigma uncertainty (ng/m3)

MCM

Calculated parameters using MCM box-model - a zero-dimensional model constrained to the measurements.
Time: data reported every 15 minutes using Start_GMT_15min.
Reported parameter names and units:
OH_mcm: OH (molecule cm-3)
HO2_mcm: HO2 (molecule cm-3)
NO3_mcm: NO3 (molecule cm-3)
N2O5_mcm: N2O5 (molecule cm-3)

HNO3

Nitric acid measured using Mist chamber/Ion Chromatography.
Time: averages using Start_UTC/Stop_UTC.
Reported parameter names and units:
HNO3_pptv: HNO3 (pptv)

HO2RO2

Total Peroxy Radicals (HO2+RO2) measured using dual channel PEroxy Radical Chemical Amplifier (PERCA).
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
HO2_RO2_pptv: HO2_RO2 (pptv)

NO

Nitric Oxide measured using ozone-induced chemiluminescence.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
NO_ppbv: NO (ppbv)

NO2

Nitrogen Dioxide measured using Photolysis and NO/O3 Chemiluminescence.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
NO2_ppbv: NO2 (ppbv)

NOy

Total reactive Nitrogen Oxides measured using Au Converter and NO/O3 Chemiluminescence.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
NOy_ppb: NOy (ppb)

NORDI

Reactive Nitrogen measured using Cavity Ring-Down.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
O3_Teco_ppbv: Teco 49 O3 (ppbv)
NO3_pptv: NO3 (pptv)
NO2_CRD_ppbv: NO2 (ppbv)
N2O5_pptv: N2O5 (pptv)
NO3_high_pptv: NO3 Uncertainty high (pptv)
NO3_low_pptv: NO3 Uncertainty low (pptv)
N2O5_high_pptv: N2O5 Uncertainty high (pptv)
N2O5_low_pptv: N2O5 Uncertainty low (pptv)
NO2_CRD_high_ppbv: NO2 Uncertainty high (ppbv)
NO2_CRD_low_ppbv: NO2 Uncertainty high (ppbv)

O3clCSD

Ozone measured using chemiluminescence.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
O3cl_ppb: Chemiluminescence O3 (ppb)

O3uvCSD

Ozone measured via UV absorbance (Thermo Environmental model 49c)
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
O3uv_ppb: UV absorbance O3 (ppb)

PANs

Peroxyacyl Nitrates measured using Gas Chromatograph/Electron Capture Detector.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
PAN_ppbv: PAN (ppbv)
PPN_ppbv: PPN (ppbv)
MPAN_ppbv: MPAN (ppbv)

SO2

Sulfur Dioxide measured using UV Pulsed Fluorescence (TECO Model 43s)
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
SO2_ppb: SO2 (ppb)

VOCsGCMSch1

Volatile Organic Compounds measured using Gas Chromatograph/Mass Spectrometer channel 1.
Time: Averages using GC_Start_UTC/GC_Stop_UTC.
Reported parameter names and units:
Acetylene_ppbv: Acetylene (ppbv)
Butadiene_13_ppbv: 1,3-Butadiene (ppbv)
c_2_Butene_ppbv: C2-Butene (ppbv)
Ethane_ppbv: Ethane (ppbv)
Ethylene_ppbv: Ethylene (ppbv)
i_Butane_ppbv: i-Butane (ppbv)
i_Pentane_ppbv: i-Pentane (ppbv)
MethylPropene_ppbv: MethylPropene (ppbv)
n_Butane_ppbv: n-Butane (ppbv)
n_Pentane_ppbv: n-Pentane (ppbv)
One_Butene_ppbv, 1-Butene (ppbv)
Propane_ppbv: Propane (ppbv)
t_2_Butene_ppbv: t2-Butene (ppbv)
Propylene_ppbv: Propylene (ppbv)

VOCsGCMSch2

Volatile Organic Compounds measured using Gas Chromatograph/Mass Spectrometer channel 2.
Time: Averages using GC_Start_UTC/GC_Stop_UTC.
Reported parameter names and units:
Too many to list

VOCsPITMS

Volatile Organic Compounds measured using Proton Transfer Ion Trap/Mass Spectrometer.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
methanol, acetonitrile, acetaldehyde, acetone, acetic_acid, isoprene, MVK_MACR, MEK, benzene, toluene, C8_aromatics, C9_aromatics, C10_aromatics, C11_aromatics, monoterpenes all in units of pptv

Aerosols

ExtCRD

Aerosol light extinction measured using Cavity Ring-Down Aerosol Extinction Spectrometer.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
Ext532_sub1: Aerosol Extinction Coefficient at 532 nm at 25% RH at STP, sub-1 micron (Mm-1)
Ext532_sub10: Aerosol Extinction Coefficient at 532 nm at 25% RH at STP, sub-10 micron (Mm-1)
AngExp_sub1: Angstrom Exponent of Extinction, 355nm/1064nm at 20% RH, sub-1 micron (unitless)
Gamma_sub1: Parameterization of Extinction Dependence on RH (fRH) at 532 nm, sub-1 micron (unitless)

PAS

Aerosol absorption measured by PhotoAcoustic Aerosol Absorption Spectrometer.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
Abs_s10_min: Absoption sub-10 micron
Abs_s1_min: Absoption sub-1 micron

Radiation

Photolysis rates (J-values)

Photolysis rates (j values) measured using filter radiometer.
Time: 1 minute averages aligned to Start_UTC
Reported parameter names and units:
j values for up-welling and down-welling radiation for various compounds.