turbidity coefficient

turbidity coefficient

[tər′bid·əd·ē ‚kō·i‚fish·ənt]
(optics)
A factor in the absorption (light) law equation that describes the extinction of the incident light beam.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The preliminary output for models M1 and M2 is originally AOD550, for G1 it is the Angstrom turbidity coefficient, [beta] = AOD1000.
In terms of the Angstrom formula, prediction of AOD[[lambda].sub.1] can be done using a second parameter, the Angstrom turbidity coefficient, [beta].
where [[tau].sub.a]([lambda]) is AOD at wavelength [lambda] (in [micro]m), [beat] is turbidity coefficient, and [alpha] is [Angstrom]ngstrom exponent (AE).
The REST2 model requires two aerosol-related inputs: the AOD at 1 [micro]m, better known as the Angstrom turbidity coefficient, [beta], and the Angstrom exponent, [alpha], that characterizes the spectral variation of AOD through Angstrom's law:
* Angstrom's turbidity coefficient [beta], unitless
Inputs Used with REST2 to Derive the Reference Data Sets for the 2009 and 2013 Handbook--Fundamentals Input 2009 Handbook-- 2013 Handbook-- Fundamentals range Fundamentals range Month 1 to 12 Not set Time 0 to 12 Not set Latitude, [degrees] 0, 15, 30, 45, 60,75 Not set Zenith angle, [degrees] Set from above 0 to 85[degrees] in 0.5[degrees] increments Station pressure, hPa 750, 1013.25 975 Precipitation water, cm 0.5, 1,2, 6 0.25, 0.5, 1.5, 3.5 Turbidity coefficient 0.01, 0.02, 0.03, 0.01, 0.03, 0.06, [beta] 0.05, 0.07, 0.1, 0.1, 0.2, 0.3 0.15, 0.2, 0.3, 0.5 Wavelength exponent 1.3 0.6, 1.0, 1.3, 1.6 [alpha] Surface albedo 0.2 0.05, 0.1, 0.2, 0.3 Table 2.
where wavelength [lambda], is in nm, [beta] is the Angstrom turbidity coefficient, and [alpha] the wavelength exponent (Angstrom, 1929, 1930; Shifrin, 1995).
BAODm is equal to the Unsworth-Monteith turbidity coefficient (Unsworth and Monteith, 1972; Gueymard, 1998).
The most important atmospheric variables are generally the aerosol optical depth (characterized here by Angstrom's turbidity coefficient and wavelength exponent) and precipitable water (a measure of the total water vapor column).
Using Angstrom's law relating the AOD at any wavelength, [[tau].sub.a[lambda]], to that at 1 [micro]m (usually referred to as Angstrom's turbidity coefficient, [beta]), it is possible to obtain [beta] and the Angstrom wavelength exponent, [alpha], by linearly fitting the data points (of AOD at different wavelengths) in log-log coordinates: