meridian plane as a common reference.. 
21 
[1 0 0 0 ] 
|0 cos2a -sin 2a 0| 
Rot(a) - - , 
10 sin2a cos2a 01 (6) 
[o 0 0 lj 
Furthermore, R sp ( 2co) is the specular reflection function and co is the incident or reflection angle to 
the facet [5]. 
2. REFLECTANCE ANALYSIS OF AIRBORNE POLDER DATA 
Preliminary analyses on the airborne POLDER data over the Mediterranean Sea was already 
done by [ 6], [7]. We have computed the theoretical reflectance for two types of aerosol models , 
namely , the log-normal type aerosol model and Junge type aerosol model. Furthermore, we only 
consider a spherical water aerosol particle whose refractive index m= n -i k in this study. The log 
normal size distribution for aerosol particles is given by Eq.(7) [3]. 
n(r) = 
:eX p[-»^] 
Xogojljt 2(logcry 
(7) , 
where a, and r 0 are the geometric standard deviation, and geometric mean radius of the aerosol 
particles. The two sets of optical parameters ( a = 2.99, and r 0 = 0.005) and ( a = 2.51, and r 0 = 0.30) 
correspond to a water-soluble aerosol model and an oceanic aerosol model, respectively. 
On the other hand , the size distribution of the Junge type aerosol model is given by Eq.(8) 
[4]. 
<r) 
f 
v + l 
C-10 
-(v + l) 
Ct 
0 
0.02 f.im ^ r £ 0.1 ¡urn 
0.1 jum is r ^ 10 /mi 
r < 0.02 f.im, r > lOjUra 
( 8 ) ,