ary
east and west in the southern Marshalls. The easterly winds extend fo great heights,
reaching .in-some -instences from the surface to 60,000 feet. Fluctuations in the easterlies are due to the passage of atmospheric waves traveling from .eost to west at
opproximately 12 knots., Thus the eastern Marshalls ore affected by the wind shifts
—.
before the western Morshalls.. Some of these. waves become transformed into cyclonic .
circulations which show up on wind maps eas vortices or eddies, ‘similar, though on-a
larger scale, to the eddies seen onthe surface of rivers.,
The transformation from
wave into vortex occurs first in the lower atmosphere and .gradually extends upward,
in contrast with the situation previously described, where the cyclones have their origin in the high atmosphere. , In general, bad weather is associated with the west-south-
west and southeast winds accompanying the rear portions of the vortex., This is also
true of the waves ‘from which the vortices originate. The worst weather is associated
with the southeast winds.,
There is a tendency for this weather to occur in the form
of long lines of cumulo-nimbus cloud, beoring striking resemblance to the cold fronts of
high latitudes, but they are more numerous than the latter within an equivdent area..
Mony vortices are quite weak, that is to say, maximum wind speeds, usually found in
the southeasterlies, do not exceed 30 knots., But there is always a likelihood of a
vortex intensifying suddenly to become a typhoon.. The best known examples are the
typhoons ~“‘Georgia"™’ and “‘Joan'’ which intensified over the Marshall Islands during
Operation Greenhouse. Though typhoons are small in area in these longitudes, they
can be extremely violent and cam cause as much damage os the great typhoons.of the
western Pocific., The damage is more restricted in area, usually being confined to one
or more atolls unfortunate enough to lie directly in the track of the storm
|
co’
(/
SS
20
RESTRIEKEDBees