Monthly mean density difference within 1 dBar (kg/m 3 ) on 10 zonal sections 
August (1902 -1954) 
E 0 
£ 20- 
8 40 
6° 7° 
, Sch iermonn ikoog 
Indefatigable,b; 
- 53.5°N 
1° 2° 
I °: 
£ 20- 
40 -L 
T" 
•|52.5°N 
E, 0 
10 t 2 H 
S 40 
4° 
Vlissingen 
|51.5°N| 
r 
2° 3° 
Longitude [W/E]