What is the aerosol optical depth?
Aerosol Optical Depth (AOD) is the measure of aerosols (e.g., urban haze, smoke. particles, desert dust, sea salt) distributed within a column of air from the instrument. (Earth’s surface) to the top of the atmosphere.
What is Aeronet data?
AERONET collaboration provides globally distributed observations of spectral aerosol optical depth (AOD), inversion products, and precipitable water in diverse aerosol regimes.
How is AOD measured?
Aerosol Robotic Network (AERONET) is a global network of ground-based sun photometers. These sun photometers are able to calculate the AOD and amount of water vapor in the atmosphere by comparing the amount of light they detect with the amount of solar radiation which would be observed in an aerosol-free atmosphere.
How is aerosol depth calculated?
Thus, the broadband aerosol optical depth, t, is computed from t = –ln(Ta)/m. This method produced broadband aerosol optical depths when measured direct normal data were already available.
How do I download data from Aeronet?
How to download data from the AERONET database
- Open the AERONET URL in your browser: http://aeronet.gsfc.nasa.gov/
- Click on +Level 1.5 AOT.
- AERONET Data Display Interface.
- Make sure that the AOT level on this page matches the level you selected on the previous page.
- Scroll down and select a site.
What is absorption Angstrom exponent?
The absorption Ångström exponent (AAE) describes the spectral dependence of light absorption by aerosols. AAE is typically used to differentiate between different aerosol types for example., black carbon, brown carbon, and dust particles.
How do you measure optical thickness?
The optical thickness of a light-absorbing medium is its geometrical thickness times its intensity attenuation coefficient. For example, an optical thickness of 1 implies that the transmitted power is reduced to 1/e (≈ 37%) of its original value. This definition is often used e.g. in atmospheric optics.
How thick is a cloud?
Three-layered clouds tend to involve a low-, middle- and high-level layer filling the atmosphere below about 10 km as might be expected given the facts that typical (average) cloud layer thicknesses are 0.5 (1.5) km and typical (average) layer separations are 1 (2) km.
What is meant by cloud fraction?
Cloud fraction is the portion of each pixel that is covered by clouds. Colors range from blue (no clouds) to white (totally cloudy). From month to month, a band of clouds girdles the equator.
What is the aerosol single scattering albedo?
Single Scattering Albedo (SSA), the ratio of scattering efficiency to total extinction efficiency, is an essential parameter used to estimate the Direct Radiative Forcing (DRF) of aerosols.