RADIAT VARIABLES

  
        
                                                                        
ALEAF:      Leaf absorption factor.                                   
                                                                        
BEAM(k):    Flux density of direct beam of wavelength k in a plane     
            perpendicular to incident sunlight.                        

BMFLX(k,j): Direct beam flux density incident in layer j of 
            wavelength band k.                              
     
CLAI(j):    Cumulative LAI in layer j.                                  
                                                                        
CT(i):      Fraction of beam flux density into angle class i in beam flux
            as would be measured perpendicular to the incidence angle.

D(k,j):     Fraction of downward diffuse radiation in total radiation 
            above canopy in wavelength band k and layer j.  

DAVE(k,j):  Average downward flux density from layer j in        
            wavelength band k.                            
                
DOWN:       Fraction of downward diffuse radiation into one layer
            in total radiation above canopy for that wavelength band
            (used in convergence).
   
DSTNET(i,j):         Net total radiation of all wavelengths into layer j 
                     and angle class i.  
                                  
DSTRAD(k,i,j):       Total radiation incident in layer j and angle class 
                     j of wavelength k (diffuse+direct beam).          

DSTRAD(k,ITOTP1,J):  Average total radiation flux density over all 
                     leaf angle classes incident in layer j
                     of wavelength k.     

EMIS:       Thermal emissivity of leaf.                            
                                                                        
EMISOL:     Thermal emissivity of soil.                       
                                                                        
ESOIL:      Soil thermal radiation flux density.
                                                                        
FBEAM(k):   Fraction of direct beam radiation of wavelength k in       
            total radiation of that wavelength above canopy
            (horizontal sensor).
  
FR(i):      Fraction of LAI in angle class i in LAI of one layer.
            A spherical distribution is assumed.               

FRAREA(i,j):         Fraction of leaf area of angle class i in sunlit
                     area of layer j (FRAREA of one layer
                     add up to SUNLIT).
 
FRAREA(ITOTP1,j):    Shaded LAI of layer j                                
                                                                        
ITOT:       Number of angle classes.                                   
                                                                        
ITOTP1:     Index number for all values averaged over all angle classes 
            in a layer.                                              

KSTRT:      Index indicating if IHR before or after sunrise/sunset: 
            (=3 for daytime and =1 for nighttime).             

PRAREA:     FAREA in percent.                                          
                                                                      
RADABV(k):  Total radiation flux density above the canopy in   
            wavelength band k.       
                           
RLAYER:     Reflectance factor of one layer.      
                                                                        
RNDIV(j):   Net total radiation flux density of all wavelengths         
            lost in layer j.        
                                   
RNET(j):    Net total radiation flux density into layer j of all 
            wavelengths.                            

RNLAM(k,j): Net radiation flux density into layer j of wavelength k 
            diffuse and direct beam.(+) downward.

SDN(j):     Fraction of downward diffuse radiation in total radiation
            above the canopy that originated in that layer from direct
            beam interception.
  
SHADE(k,j): Fraction of LAI of LAI of layer j that is shaded from     
            wavelength band k.                         
         
SIGMA:      Constant used in calculation of blackbody radiation.    
                                                                        
SOURCE                                                                  
                                                                        
SUNLIT:     LAI of a layer that is sunlit.                            
                                                                        
SUP(j):     Fraction of upward diffuse radiation in total radiation above 
            the canopy that originated in that layer from direct beam
            interception. 
 
TBEAM(j):   Fraction of direct beam in direct beam above the canopy     
                passing through layer j.    
                                         
TEMPLF(ITOTP1,j):    Average leaf temperature over all angle classes 
                     in layer j.                       

TEMPLF(i,j):         Leaf temperature in angle class i and layer j.
                                                                        
TLAYER:     Transmittance factor of one layer.         
                                                                        
TSFC:       Soil surface temperature.                                 
                                                                        
U(k,j):     Fraction of upward diffuse radiation in total radiation 
            above canopy in wavelength band k and layer j.   

UP:         Fraction of upward diffuse radiation into one layer in total
            radiation above canopy for that wavelength band (used in
            convergence).