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albedo

PURPOSE ^

ALBEDO: computes sea surface albedo following Payne (1972).

SYNOPSIS ^

function alb=albedo(trans,sunalt)

DESCRIPTION ^

 ALBEDO: computes sea surface albedo following Payne (1972).
 alb=ALBEDO(trans,sunalt) computes the sea surface albedo from the
 atmospheric transmittance and sun altitude by linear interpolation 
 using Table 1 in Payne (1972), J. Atm. Sci., 29, 959-970. Assumes 
 trans and sunalt both matrices of same size. Table 1 is called 
 albedot1.mat.

 INPUT:   trans - atmospheric transmittance 
          sunalt - sun altitude [deg] 
 
 OUTPUT:  alb - albedo

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function alb=albedo(trans,sunalt)
0002 % ALBEDO: computes sea surface albedo following Payne (1972).
0003 % alb=ALBEDO(trans,sunalt) computes the sea surface albedo from the
0004 % atmospheric transmittance and sun altitude by linear interpolation
0005 % using Table 1 in Payne (1972), J. Atm. Sci., 29, 959-970. Assumes
0006 % trans and sunalt both matrices of same size. Table 1 is called
0007 % albedot1.mat.
0008 %
0009 % INPUT:   trans - atmospheric transmittance
0010 %          sunalt - sun altitude [deg]
0011 %
0012 % OUTPUT:  alb - albedo
0013 
0014 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0015 % 3/10/96: version 1.0
0016 % 7/24/98: version 1.1 (rev. to handle out-of-range input values by RP)
0017 % 8/5/99:  version 2.0
0018 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0019 
0020 % load table 1
0021 load albedot1
0022 
0023 % create axes
0024 x=[0:2:90];
0025 y=[0:.05:1.0]';
0026 
0027 alb=ones(size(trans))+NaN;
0028 k=sunalt>0 & finite(trans) & trans<=1.01;
0029 
0030 % interpolate
0031 alb(k)=interp2(x,y,albedot1,sunalt(k),trans(k));
0032 
0033

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