Total heat content in the North Sea 
(area: 51,2 to 59,25 0 N, see chart on left side; 
volume: 27500 km 3 ) 
8.0E+20 - 
c 
O 
o 
03 
_c4.0E+20 
2.0E+20 - 
O.OE+OO -- 
Jan 
“1 I I I I I I I I I r - 
Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 
Month