at the bound-
aries. With longitude, 
l , parameterised as a function of latitude, f , these boundaries are at
l1 = 30 
30
40
(f  40) (2)
and
l2 = 45 
90
40
(f  40) : (3)
This suggests dividing the study domain into three parts: a western sector, with 
l < l1, covering
the region west of Greenland; a central sector, with l1  
l < l2, including the region of the
Icelandic Low; and an eastern sector
        
/media/vedurstofan/utgafa/skyrslur/2015/VI_2015_005.pdf