Other Names

Aerosol Optical Depth, τ, tau

Definition

"Aerosol Optical Thickness" is the degree to which aerosols prevent the transmission of light.
The aerosol optical depth or optical thickness (τ) is defined as the integrated extinction coefficient over a vertical column of unit cross section. Extinction coefficient is the fractional depletion of radiance per unit path length (also called attenuation especially in reference to radar frequencies). The optical thickness along the vertical direction is also called normal optical thickness (compared to optical thickness along slant path length).

Applications

(1) Atmospheric correction of remotely sensed surface features	(5) Air Quality
(2) Monitoring of sources and sinks of aerosols	(6) Health and Environment
(3) Monitoring of volcanic eruptions and forest fire	(7) Earth Radiation Budget
(4) Radiative Transfer Model	(8) Climate Change

GES DISC Datasets

Quick Search for 'Aerosol Optical Thickness' with Mirador
Click on the corresponding 'WHOM access' links in the table below to access products containing specific parameter.

Parameter	Units	Platform /Instrument	Data
			Begin Date	End Date	WHOM Access	Doc
Aerosol Optical Thickness at ground pixel resolution	None	Aura/OMI	2004-08-15	Current	OMAERUV.003	Y
Aerosol Optical Thickness at ground pixel resolution globally binned (0.25 deg lat/lon grid)	None	Aura/OMI	2004-08-15	Current	OMAERUVG.003	Y
Aerosol Optical Thickness, globally gridded(1 deg lat/lon grid resolution)	None	Aura/OMI	2004-08-15	Current	OMAERUVd.003	Y
Aerosol Optical Thickness at 0.38 µm over land and ocean globally gridded (~1 x 1.25 deg grids)	None	Earth Probe/TOMS	1996-07-25	2005-12-31	TOMSEPL3	Y
		Meteor-3/TOMS	1991-08-22	1994-12-27	TOMSM3L3	Y
		Nimbus-7/TOMS	1978-11-01	1993-05-06	TOMSN7L3	Y

Other sources for data

1. AVHRR (NOAA-7, 9,11,14) 2. MISR (Terra) 3. POLDER (ADEOS) 4. SCIAMACHY(Envisat) 5. AERONET (Global Ground-based Sun-photometer Network)