AERONET Data Units (Aerosol Robotic Network)

cm = centimeter (10E-2 m) ; µm = micrometer (10E-6 m); nm = nanometer (10E-9 m); µW = microwat t (10E-6 W); mV = millivolts (10E-3 V) T - Total data mode C - Coarse data mode F - Fine data mode sr = steradian % = percent BOA - bottom of the atmosphere TOA - top of the atmosphere

AERONET Data Units (Aerosol Robotic Network)

Data Type	Column Header	Column Header Units	Data Units
Data Products
Direct Sun Measurements
Aerosol Optical Depth (AOD) Levels 1.0, 1.5, and 2.0	AOT_(wavelength)	wavelength in nm	None
%TripletVar is the AOD "triplet variability" multiplied by 100.	%TripletVar_(wavelength)	wavelength in nm	None
Angstrom Parameter	(AOD1)-(AOD2)Angstrom	wavelength range in nm	None
Water Vapor	Water(cm)	wavelength at 940 nm	cm^3/cm^2 or g/cm^2
Spectral Deconvolution Algorithm Output (SDA) from Direct Sun Measurements
Total AOD 500nm	Total_AOD_500nm[tau_a]	wavelength in nm	None
Fine Mode AOD 500nm	Fine_Mode_AOD_500nm[tau_f]	wavelength in nm	None
Coarse Mode AOD 500nm	Coarse_Mode_AOD_500nm[tau_c]	wavelength in nm	None
2nd Order Reg Fit Error - Total AOD 500nm (SDA	2nd_Order_Reg_Fit_Error-Total_AOD_500nm[regression_dtau_a]	wavelength in nm	None
RMSE Fine Mode AOD 500nm	RMSE_Fine_Mode_AOD_500nm[Dtau_f]	wavelength in nm	None
RMSE Coarse Mode AOD 500nm	RMSE_Coarse_Mode_AOD_500nm[Dtau_c]	wavelength in nm	None
RMSE Fine Mode Fraction 500nm	RMSE_FineModeFraction_500nm[Deta]	wavelength in nm	None
Angstrom Exponent - Total 500nm	Angstrom_Exponent(AE)-Total_500nm[alpha]	wavelength in nm	None
dAE/dln(wavelength)-Total 500nm	dAE/dln(wavelength)-Total_500nm[alphap]	wavelength in nm	None
Angstrom Exponent-Fine Mode 500nm	AE-Fine_Mode_500nm[alpha_f]	wavelength in nm	None
dAE/dln(wavelength)-Fine Mode 500nm	dAE/dln(wavelength)-Fine_Mode_500nm[alphap_f]	wavelength in nm	None
Input AOD to SDA	(wavelength)_Input_AOD	wavelength in nm	None
Sky Radiance Measurements
Almucantars (Sky Radiance)	(azimuth angle)	degrees	µW/cm^2/sr/nm
Principal Planes (Sky Radiance)	(scattering angle) from -6 to 6 uses sun collimator from 6 to 150 uses sky collimator	degrees	µW/cm^2/sr/nm
Polar Principal Planes(Sky Radiance)	(zenith angle)P(polarized channel number)	degrees	µW/cm^2/sr/nm
Degree of Polarization	(zenith angle)[degofpol]	degrees	None
Sky and Surface Radiance for BRDF	(scattering angle)(SAZ=(solar azimuth angle)	degrees, degrees	µW/cm^2/sr/nm
Cloud Mode Radiance	zenith	0 degrees	µW/cm^2/sr/nm
Aerosol Inversion Retrievals from Sky Radiance Measurements
SKYRAD.PAK	center of size bins (logarithmic scale)	µm	10^5 * µm^3/µm^2
Size Distribution dV®/dln r	discrete size points (logarithmic scale)	µm	µm^3/µm^2
Single Scattering Albedo	SSA(wavelength)	wavelength in nm	None
Refractive Index (real part)	REFR(wavelength)	wavelength in nm	None
Refractive Index (imaginary part)	REFI(wavelength)	wavelength in nm	None
Volume Concentration	VolCon	None	µm^3/µm^2
Effective Radius	EffRad	None	µm
Volume Median Radius	VolMedianRad	None	None
Standard Deviation	StdDev	None	None
AOD Coincident	AOT_(wavelength)	wavelength in nm	None
AOD Extinction	AOTExt(wavelength)	wavelength in nm	None
AOD Absorption	AOTAbsp(wavelength)	wavelength in nm	None
Phase Functions	(scattering angle)[wavelength]	degrees, nm	None
Asymmetry Factor	ASYM(wavelength)	wavelength in nm	None
Broadband Flux	Downward/Upward at BOA and TOA	wavelength in nm	W/m^2
Spectral Flux	Downward/Upward/Diffuse	wavelength in nm	W/m^2
Radiative Forcing	At BOA and TOA	wavelength in nm	W/m^2
Radiative Forcing Efficiency	At BOA and TOA	wavelength in nm	W/m^2
Other Data and Parameters
Date/Time	Date, Time	None	GMT Solar Day/GMT Time
N (Number of Measurements for Average)	N[]	None	None
Altitude	Altitude	None	km
Solar Zenith Angle for 1020nm Channel (average between left and right almucantars)	solar_zenith_angle_for_1020nm _scan	None	Degrees
Average Solar Zenith Angle for Broadband Flux Calculation	average_solar_zenith_angle_for_ flux_calculation	None	Degrees
Julian Day	Julian_Day	None	Days
Size Index, Num of Angles	siz_index,num_of_angles	None	None
Alm_type (Data level identifier)	alm_type	None	None
Sky Error, Sun Error	sky_error	None	%
AOD at 440 nm	tau440(measured)	None	None
Spectral Albedo	Albedo_ Wavelength	wavelength in nm	None
Sphericity Parameter	Sphericity Parameter	None	%
Optical Air Mass	Air_Mass	None	None
Exact Wavelength of Instrument Filter	AOT_(wavelength) Exact Wavelength	wavelength in nm	µm

Key:

cm = centimeter (10E-2 m) ; µm = micrometer (10E-6 m); nm = nanometer (10E-9 m);
µW = microwat

t (10E-6 W); mV = millivolts (10E-3 V)

T - Total data mode
C - Coarse data mode
F - Fine data mode

sr = steradian
% = percent

BOA - bottom of the atmosphere
TOA - top of the atmosphere