How is scattering different from albedo?
Single-scattering albedo is unitless, and a value of unity implies that all particle extinction is due to scattering; conversely, a single-scattering albedo of zero implies that all extinction is due to absorption. Scattering albedo equations have yet to be determined in elliptical, toroidal, conical and many others.
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. However, SSA is one of the large contributors to the uncertainty of DRF estimations.
How do you calculate scattering efficiency?
The backscatter cross section CΠ(λ, r) (m2 sr−1) determines the amount of power scattered into the backscattering direction per unit solid angle. The backscatter efficiency QΠ(λ, r) is again the ratio of the scattering cross section to the geometric cross section.
What is meant by 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. The voltage (V) measured by a sun.
What is asymmetry parameter?
The asymmetry parameter (g) is defined as the intensity-weighted average cosine of the scattering angle: where θ is the angle between incident light and scattering direction and P(θ) is the angular distribution of scattered light (the phase function).
What are 3 things that can happen to light as it passes through the atmosphere?
When light strikes a new medium, the light can be reflected, absorbed, or transmitted. When light is transmitted, it can be refracted, polarized, or scattered.
What is coefficient of scattering?
The scattering coefficient is a measure of the ability of particles to scatter photons out of a beam of light, while the absorption coefficient is a measure of how many photons are absorbed. Each parameter is expressed as a number proportional to the amount of photons scattered or absorbed per distance.
What is the aerosol index?
The Aerosol Index (AI) is a qualitative index indicating the presence of elevated layers of aerosols with significant absorption. The main aerosol types that cause signals detected in the AI are desert dust, biomass burning and volcanic ash plumes.
What is AOD measured in?
Aerosol Optical Depth
Aerosol Optical Depth (AOD) is a quantitative estimate of the amount of aerosol present in the atmosphere, and it can be used as a proxy for surface Particulate Matter PM2. 5 (particles smaller than 2.5 µm median diameter). AOD measures the extinction of a ray of light as it passes through the atmosphere.
What reflects sunlight in space?
Clouds, especially, low, thick clouds, reflect incoming sunlight (shortwave radiation) back to space. High clouds reflect less solar radiation and trap longwave, infrared radiation (heat) re-radiated from Earth’s surface.
What is the aerosol single scattering albedo ωo?
The aerosol single scattering albedo, ωo, defined as the fraction of the aerosol light scattering over the total extinction, is one of the most important properties of aerosols. The direct radiative effect of aerosols is very sensitive to ωo.
Does surface albedo affect aerosol emissions?
Aerosols with such values for ωo can have a cooling or warming effect on the climate over land surfaces, pending on the magnitude of the surface albedo. The broadband surface albedo around the Xianghe site is about 15%, resulting in a neutral aerosol effect.
What is the surface albedo around the Xianghe site?
The broadband surface albedo around the Xianghe site is about 15%, resulting in a neutral aerosol effect.
Who determined the ground albedo and index of absorption of atmospheric particulates?
King, M. D., and B. M. Herman ( 1979 ), Determination of the ground albedo and the index of absorption of atmospheric particulates by remote sensing, Part I: Theory, J. Atmos. Sci., 36, 163 – 173 .