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2.4.4. Scattering phase function. When using the classic Case 1 IOP model, the user
must also specify the scattering phase function to be used for particle scattering. This can
be done in various ways, e.g. by picking a particular phase function (such as the Petzold
“average-particle” phase function defined in Mobley, et al., 1993), or by specifying the
particle backscatter fraction Bp = bbp/bp, which is then used to generate a Fourier-Forand
phase function with that backscatter fraction (Mobley, et al., 2002).
Morel et al. (2002) developed a phase function model for Case 1 water in which the
phase function is a combination of “small” and “large” particle phase functions, with the
fraction of each being determined by the chlorophyll concentration:
(11)
where
and ál = 1 - ás. Figure 9 shows phase functions determined by Eq. (11), along with the
frequently used Petzold average-particle phase function.
Fig. 9. Phase functions for small (orange) and large (red) particles as given by Morel et al.
(2002). Phase functions as given by Eq. (11) for Chl = 0.01 (purple), 0.1 (blue), 1.0 (teal),
and 10.0 (green), and the Petzold average particle phase function (black) are also shown.
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