? Scho 
   
   
  
  
  
  
  
  
  
  
    
     
   
  
  
  
  
  
  
     
  
   
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
   
KEY Y 
ABST! 
Snow « 
climate 
image 
in the 
The de 
the dec 
surface 
results 
all rem 
In higl 
snow. 
areas ^ 
month 
downs 
gaps | 
station 
Snow : 
global 
geomo 
highes 
hydrol 
cover 
region 
Consi 
great 
for rel 
using 
requir 
detect 
Cloud 
difficu 
challe 
cloud, 
the sn 
(2) the 
the clc 
The N 
isa 3 
radiati 
  
* silve