Jökull - 01.12.1969, Blaðsíða 80

26° 24° 22° 20° 18° 16° 14° 12°
Fig. 10.
Drift ice off the
north coast of
Icelancl on May
10, 1965, after a
period of three
weeks of easter-
ly winds. The
Icelandic Coast
Guard reconais-
sance flight.
of Iceland. The southeasterly wind component
was zero both these months, and one can argue
that a mean wind thrust onto the ice edge to
keep it in the East Greenland current is miss-
ing. It has also been pointed out that the
turbulence over partly open water at an ice
edge is bound to cause scattered floes to drift
considerably faster than the main ice and that
their speed is likely to be as great as 4°/0 of
the wind speed, or even greater. It has been
shown that the northeasterly wind along the
east coast of Greenland takes a gootl part in
the ice drift southwards in winter ancl that
this part varies greatly from month to month.
It appears that the ice drift is rnore depend-
ent on winds in the region between Iceland
and Jan Mayen than it is farther north. Also
the fact stands out that the past six years the
winter winds are rnore northerly than the six
years before, thus explaining, at least partly,
the increasing amount of ice in Icelanclic wat-
ers.
Finally I want to stress the need of close
watch of winds and pressure pattern north of
Iceland not only monthly but daily, if one is
to attempt the forecasting of ice arrival at the
north coast of Iecland. It is also necessary to
keep track of the ice edge as far north as to
76 JÖKULL 19. ÁR
Jan Mayen. This may possibly be done by the
use of satellite pictures, but weekly reconnais-
ance flights are to be recommended.
REFEREN CES
British Hydrographic Department of the Ad-
miralty. H: D: 421, March 1946: Investiga-
tion into the reasons for extension of ice
field from Greenland to northern and
eastern coasts of Iceland.
Deutscher Wetterdienst, Seewetteramt, Ham-
burg: Die Witterung in Ubersee, 1956 to
1967, incl.
Eythórsson, Jón. 1965: Report on Sea Ice off
the Icelandic Coasts Oct. 1964—Sept. 1965.
Jökull 15: 151-156.
Icelandic Coast Guard: Charts from ice recon-
naissance flights in 1965.
Marine Division of the British Meteorological
Office: Ice at the End of the Month, Ice
charts March 1962 to Feb. 1968.
SvercLrup, H. U. 1942: Oceanography for Mete-
orologists. Prentice Hall, Inc., New York.
Veðurstofan, Reykjavík: Veðráttan 1965.
Veðurstofan, Reykjavík: Daily weather Maps,
Dec. 1964 to May 1965.