DIFFINT VARIABLES

ADUM:      Ratio of upward to downward fluxes for diffuse radiation.   
                                                                        
D(K,J):    Downward diffuse radiation above sublayer J divided by downward
           diffuse radiation above the layer, subscript wavelength band K.

DF:        Leaf area index increment of one canopy layer.                   
                                                                        
DIFSUB:    Fraction of diffuse radiation that passes unintercepted 
           through one sublayer. 
                                                   
DIRSUB:    Direct beam non-interception factor for sublayer.                
                                                                        
DOWN:      Fraction of downward diffuse radiation passing through one       
           sublayer (used in convergence). 
                                  
EXPDIF:    Fraction of diffuse radiation that passes unintercepted 
           through one layer. 
                                                      
LAYSP1:    LAYSUB + 1                                                       
                                                                        
 LAYSUB:    Number of sublayers in a layer (currently set to 10).
                                                                        
RLAYR:     Reflectance factor for diffuse radiation of a layer. 
           Subscripted by K for wavelength band.  
                                     
RSUBL:     Reflectance factor for diffuse radiation of a sublayer. 
           Subscripted by K for wavelength band. 
                                                   
SDNSUB:    Fraction of intercepted direct beam that is scattered 
           downward in one sublayer.   
                                       
SOURDN:    Source term for downward diffuse radiation for the 
           wavelength band K and IHR for one layer.
                                    
SOURUP:    Source term for upward diffuse radiation for the 
           wavelength band K and IHR for one layer.
                                    
SUPSUB:    Fraction of intercepted direct beam that is reflected 
           upward in one sublayer.   
                                       
TLAYR:     Transmittance factors for diffuse radiation of a layer. 
            Subscripted by K for wavelength band.   
                             
TSUBL:     Transmittance factors for diffuse radiation of a sublayer. 
           Subscripted by K for wavelength band.   
                                                
U(K,J):    Upward diffuse radiation above sublayer J divided by downward
           diffuse radiation above the layer, subscript wavelength band K.

UP:        Fraction of upward diffuse radiation passing through one         
           sublayer (used in convergence).