At present only available with rte_solver DISORT2.
The number of streams (nstr) is automatically increased
to 16 if cox_and_munk BRDF is switched on, to avoid numerical
problems. The default value is 0.01 mg/m
. To switch on Cox and Munk
BRDF, specify any of the cox_and_munk options and define at least
cox_and_munk_u10.