928 POLAR METHOROLOGY 
Fluctuations of the meteorological variables in the Ross 
Sea area can be attributed to a succession of depressions not 
differing materially from those of lower latitudes. ...Apart 
from some brief periods, the pressure systems of the Ross 
Sea are connected with, and have a definite effect on, the 
systems further north... .Blizzards set in when the isobars 
(usually in the rear of a depression) coincide with the direction 
of the down slope winds. 
Except for some rather forced analyses, Ramage’s 
interpretations are rather convincing: there is an 
obvious relation between the Ross Sea cyclones and 
westward-moving pressure waves, but whether the rela- 
tion is one of simple cause-and-effect or one of steering- 
and-intensification cannot be determined. 
Suggestions. Little attention has been given to one 
aspect of the pressure waves: while their amplitude is 
constant (about 0.6 in.) throughout Antarctica and 
even at subantarctic islands, their period decreases 
steadily from Framheim to Cape Denison. (Simpson 
and Loewe confusingly called the duration in hours the 
wave length.) If these are classical waves, in which the 
product of wave speed and period gives wave length 
(distance, not duration), then waves travelling from 
Framheim to Cape Denison with period decreasing 
from 163 to 102 hours must either increase in speed or 
shorten in length, or both. 
As Lamb has suggested, it is likely that Antarctica’s 
coast is affected both by westward-moving pressure 
waves and “the familiar effects of fronts and depres- 
sions;...these apparently conflicting influences can be 
seen as interlocking parts of the same’ atmospheric 
circulation.”” Much of the wide variation in pressure 
waves, and the several anomalous weather sequences 
which have forced wave opponents into rather tortuous 
synoptic analyses, can be explained by assuming that 
both processes are at work. 
Arctowski, the first meteorologist to winter in ant- 
arctic regions (on the Belgica, 1898-99), has suggested 
(5) that 
Even the formation of lows and highs of pressure, their 
tracks and their changes in form and extent, may be directly 
produced by atmospheric waves....' Most probably the 
pressure changes observed on Kerguelen Island are the prod- 
uct of two intercrossing systems of waves, one of them origi- 
nating on the Antarctic continent. 
Synoptic evidence of a westward-moving antarctic 
pressure wave (misnamed a surge), and a possible ex- 
planation for it, were found by Lamb [81] on the maps 
covering all Antarctica which he drew at the end of a 
summer on Antarctica’s Indian Ocean coast: 
Between 19 and 23 March 1947 a pressure surge [wave] 
moved from east to west across Antarctica, starting from 
James W. Ellsworth Land, but...seems to have come in 
from outside, originating in the breakdown of the subtropical 
high-pressure system of the south-west Pacific east of New 
Zealand. This view carries with it the further suggestion that 
warm air of subtropical origin was transferred, particularly 
in the levels of the atmosphere above about 4,000 feet, far 
to the south and possibly right over Antarctica. No informa- 
tion exists to show what temperatures might be observed in 
this air upon its arrival over Antarctica or how rapidly it 
would be chilled thereafter by the radiation conditions of 
high latitudes; such invading warm air would in any case 
normally be separated by a shallow surface layer of extremely 
cold air from the actual ice of the antarctic plateau, but it is 
likely that the more abrupt mountain peaks and ranges would 
penetrate it. (See also [76]) 
Another example of a warm polar anticyclone, ‘‘its 
warmth due to subsidence in the whole air mass of 
which it was constituted” and maintained by inflow of 
air at high levels from the northeast above a vigorous 
and extensive disturbance over New Zealand, was 
studied in detail by Palmer [62]. However, he did not 
recognize that this anticyclone, or a part of it, caused a 
typical pressure wave at Little America on 29 Novem- 
ber 1929 as it moved northwest. 
The anticyclone, deduced from hodograph analysis 
of two long balloon runs on the 29th to be “south of 
Little America,” was actually over the polar plateau. 
Byrd’s South Pole flight [115] through it on the 29th 
(GMT) encountered southerly winds throughout, and 
reported clouds forming to the east over the mountains. 
Gould [124], heading the geological party 350 miles 
south of Little America at the southern head of the 
Ross Shelf Ice, noted on the 27th that “our bad weather 
was moving northward for, as conditions improved 
with us, they had grown less favorable at Little 
America.” Gould’s camp had ‘perfect weather” all of 
the 28th (GMT); it remained warm and clear until 
late on the 30th, when a slight south breeze freshened 
into “a veritable antarctic blizzard” which was ‘the 
warmest southern wind we had ever faced and grew 
warmer as we neared the mountains’; southerly winds 
usually were biting cold, but this one was uncom- 
fortable because of its strength, not because of its 
temperature. 
Hypothesis. To incorporate this mformation, Pal- 
mer’s three synoptic maps for 28, 29, and 30 November 
may be revised and extended south and west of Little 
America to show a lobe of a polar anticyclone moving 
out along about 140°E (one of the anticyclone cells 
postulated by the Highjump aerologists, representing 
frequent outflow, is along 145°H or 155°H; one of 
Lamb’s high pressure centers is at 130°E). Palmer’s 
hodograph for 1600 on the 29th indicates “that the 
anticyclone was becoming less intense and was probably 
re-oriented to extend off the continent somewhere in 
the northwest.” 
Pressure at Little America reached a maximum of 
29.55 in. from 1000 to 1200 on the 29th (GMT), a rise 
of 0.22 in. in 26 hours, then fell 0.21 im. in 21 hours as an 
occlusion approached from the northwest. Both these 
changes exceed 0.20 in., the criterion for a “pressure 
wave.’’ Winds remained easterly during the entire two 
days between pressure minima, but were 12 to 18 mph 
during the day and a half preceding the maximum and 
decreased to 3 mph or less for ten hours during the 
subsequent pressure fall, then turned NE and increased 
as the occlusion passed. 
In this case, passage of a relatively weak warm anti- 
cyclone several hundred miles to the westward did little 
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