Jökull - 01.12.1969, Blaðsíða 63

vestigations have been made of many of the
factors and phenomena entering this anaiysis
but many of tliese have been limited to the
Arctic Ocean area. It is therefore uncertain to
what degree these may be applied to the area
of interest in the paper. Some other data rieed-
ed for the analysis are either very difficult or
impossible to obtain.
Extensive measurements have been made in
the Arctic of the effects of winds and currents
on ice movemcnts, the thickness of the ice, and
the formation and melting of the ice. These
results apply almost exclusively to a continuous
or very dense ice field and their application
to ice drift of low Concentration must be made
W’ith care. Winds and currents can, for example,
be expected to exert a considerably greater
force per unit area of a small floe of ice than
°n a continuous ice field. This phenomenon
has been reported by some observers (Fuku-
tomi 1948).
Synoptic data from the area needed for the
analysis can be very difficult or impossible to
obtain. These include velocity and direction of
winds and currents. Weather observations in
the area are very sparse and winds must be
estimated or computed from weather maps
which are prepared from very limited informa-
tion and probably in many instances from pure
guesswork. Although the present author is not
familiar with this field it seems obvious that
such data can not be very reliable. Ocean cur-
fents in the area are even more of a question
mark than the surface winds. Oceanographic
nieasurements under the ice are very difficult
t° make, and it coulcl be that this problem
must be approached by attempting to set up a
mathematical model of the area and calculate
the currents as was done f. ex. by Campbell in
his studies of ice movements in the Beaufort
Sea (Campbell 1964). It must be borne in mind,
however, tliat such a model is at best only as
reliable as the clata from which it is built, ahd
tt is therefore not certain how well it would
Work in the present case. In any event, this is
a matter needing careful study.
From the foregoing comments someone might
conclude that calculating the ice drift in the
East Greenland Current is a hopeless task due
t° the many uncertain and unknown factors
entering the problem. This, however, is not
necessarily the case, although it has been point-
ed out, that many problems remain to be
solved before such calculations can be hoped
to be of any use. These are difficult problems
to be sure and a challenge for anyone who
attempts to find their solution. These are also
problems of practical importance to lceland,
because indications are that the year 1968 was
not the last year in wliicli the ice will visit
Iceland.
From scientific viewpoints — geophysical,
meteorolögical, and oceanographic — tlie
formation of the sea ice and its behavior
are also of great interest. The effects of the
ice on the energy balance of the earth are far
from being completely understood, and many
problems rernain unsolved in this area. Few7
spots on the earth are better situated than
Iceland to undertake studies of the type dis-
cussed in this paper, and Icelanders have there-
fore here a good opportunity to contribute to
better understanding and increased knowledge
in this field.
JÖKULL 19. ÁR 59