Working with optical property and source function values

Shared behavior

Variables of class ty_optical_props_arry must be allocated as well as initialized before use. Because the argument list is slightly different among the sub-classes each allocation routine has a distinct name. Users must call one of err_msg = op%alloc_1scl(ncol, nlay), err_msg = op%alloc_2str(ncol, nlay) or err_msg = op%alloc_nstr(nmom, ncol, nlay).

Initialization from an existing variable of type ty_optical_props can be combined with allocation: err_msg = op%alloc_2str(ncol, nlay, op1), etc.

Integer functions op%get_ncol() and op%get_nlay() return the number of columns or layers in the domain. Class ty_optical_props_nstr has a get_nmom() function.

err_msg = op%subset(start, n, subset) extracts columns start to start+n-1 from variable op into variable subset. For optical properties assumptions are made if op and subset are of different classes.

Class ty_source_func_lw share these behaviors, though allocation and/or initialization does not require specifying the type (i.e. err_msg = source_func%alloc(ncol, nlay)).

Working with optical property values

Calling err_msg = op%delta_scale(for) will delta-scale the optical properties to remove strong forward peaks in the phase function. Optional argument for is an real array of forward-scattering fractions with the same extents as op%tau. If this argument is omitted the assumption for = g*g is made.

Optical properties can be added together: err_msg = op1%increment(op2) adds the optical properties of op1 to those of op2 making reasonable assumptions if the two variables are not of the same class.

err_msg = op%validate() checks to be sure that all values are valid: optical depth not less than 0, single-scattering albedo between 0 and 1, asymmetry parameter between -1 and 1.

Reference

A complete description of the optical properties and source function implementations is also generated from the source code.