The IASOA Arctic aerosol dataset includes aerosol optical property data and met data (T, RH, P, WS and WD) from 6 Arctic monitoring stations (ALT = Alert, Canada; BRW = Barrow, Alaska; PAL = Pallas, Finland; SUM = Summit, Greenland; TIK = Tiksi, Russia; ZEP = Ny Alesund (Zeppelin Mountain), Norway). The data are from years 2012-2014, and are 1-hour averages. Timestamps mark the start of the 1-hour averaging period.  

Variable Descriptions:
Station: 3-letter station identifier
DateTimeUTC: Date and time in UTC (YYYY-MM-DD hh:mm:ss)
Epoch: Seconds since 1970-01-01
Bs[450,550,700]: Aerosol scattering coefficient from nephelometer at 450nm, 550nm, 700nm  wavelengths (1/Mm)
Bbs[450,550,700]: Aerosol backscattering coefficient from nephelometer at 450nm, 550nm, 700nm wavelengths (1/Mm)      
Ba[467,528,652]_clap: Aerosol absorption coefficient from CLAP at 467nm, 528nm, 652nm wavelengths (1/Mm)
Ba[467,525,530,660]_psap: Aerosol absorption coefficient from PSAP at 467nm, 525nm, 530nm, 565nm wavelengths (1/Mm)
Ba[637]_maap: Aerosol absorption coefficient from MAAP at 637nm wavelength  
ATN[370-950]: Aethalometer attenuation values for 7 wavelengths (370,470,520,590,660,880,950nm)
Batn[370-950]_aeth: Aethalometer attenuation coefficients for 7 wavelengths (370,470,520,590,660,880,950nm)***
T: Ambient temperature (degC)
U: Ambient relative humidity (%)
P: Ambient pressure (hPa)
WD: Wind direction (degrees true) 
WS: Wind speed (m/s) 
Batn_int[467,525,637]: Aerosol attenuation coefficient interpolated to common wavelength of 467nm, 525nm, and 637nm 
Babs_int[467,525,637]: Aerosol absorption coefficient interpolated to common wavelength of 467nm, 525nm, and 637nm
ATN[467,525,637]_int: Attenuation values interpolated to common wavelength of 467nm, 525nm, and 637nm

***Attenuation coefficients are un-corrected absorption coefficients from the aethalometer- calculated with the equation: batn = (S*((ATN2-ATN1)/100))/(F*(t2-t1)), where S=spot size, ATN=attenuation value, F=flow rate, and t=time. 

The scattering data included are at three wavelengths (450, 550 and 700nm)
from a TSI nephelometer at each of the six stations. All scattering data are
corrected with the Anderson & Ogren (1998) truncation correction. Reference 
absorption data are included for each of the six stations, though reference 
absorption instrument and wavelengths differ by site. BRW and SUM have reference 
absorption from a CLAP (467, 528 and 652nm), ALT has reference absorption data from 
a 3-wavelength PSAP (467, 530, and 660nm), ZEP has reference absorption data
from a 1-wavelength PSAP (525nm) that have been adjusted using a factor of
1/1.52 as recommended by the data provider, and PAL and TIK have reference
absorption data from a 1-wavelength MAAP (637nm). Reference absorption data 
from the PSAP and CLAP have been corrected with the Bond et al. (1999) 
correction, data from the MAAP are internally corrected in the instrument as described 
in Petzold & Schonlinner (2004). The dataset also includes aethalometer absorption 
data from all six stations. ALT, BRW, PAL, TIK, and ZEP aethalometer data 
are from a 7-wavelength (370,470,520,590,660,880,950nm) aethalometer model AE31. 
SUM aethalometer data are from a 1-wavelength (880nm) aethalometer model AE16.
ATN values and attenuation coefficients (calculated as specified above) from 
the aethalometers are included in the dataset and are uncorrected. All six 
stations have meteorological data including temperature, relative humidity, 
pressure, wind direction and wind speed included. Finally, aerosol ATN values, 
attenuation coefficients, and reference absorption coefficients are 
interpolated to common wavelengths of 467, 525 and 637nm for ease of direct
comparison between aethalometer attenuation coefficients and reference absorption 
coefficients.

Missing values are indicated with a blank (in other words, double
commas ',,' in the .csv file). No NAs or NaNs are used.

All data are reported at STP, T= 273.15K and P=1013.25hPa.