207 
1914-15.] Meteorological See-Saw over Antarctic Seas. 
process due to the great transference of air from lower latitudes to the 
Antarctic Continent. It must be kept in mind that neither Laurie Island 
nor M‘Murdo Sound are situated in “action centres.” The Weddell Sea 
barometric minimum is located some 300 miles to the south of the South 
Orkneys and the Ross Sea minimum to the east-north-east of MMurdo 
Sound.^ What we are really discussing is therefore a somewhat modified 
result of the changes taking place, on the one hand, in the adjacent 
foci of cyclonic activity, and on the other in the conditions on the great 
Antarctic plateau — doubtless the controlling factor. As regards Laurie 
Island, the advance or retreat of the anticyclonic area that normally covers 
the south of Graham’s Land is also a prominent factor, more especially 
during late spring and early summer. 
It will be noted that the seasonal variations of wind force at Evangelists’ 
Island are in remarkable agreement with those recorded at M'Murdo 
Sound, since the signs differ in only one season, viz. the winter of 1911, 
while they are the reverse of those at Laurie Island except in the spring 
of 1903. 
As there is an agreement between the departures from the normal in 
pressure temperature and wind velocity at Laurie Island and on the west 
coast of Graham’s Land,f it follows that the Antarctic circulation in the 
South Pacific in high latitudes (63°-70° S.) must be in harmony with that 
in the Weddell Sea in similar latitudes. This indicates that the atmo- 
spheric circulation in the Bellingshausen Sea at least as far west as 100° W. 
long, is controlled, as is the circulation in the Weddell Sea as far east as 
the Greenwich meridian, by the conditions prevailing over the south of 
Graham’s Land and the continental area located to the south-west and 
* The mean wind at Cape Evans and Framheim during the period under review was 
about E.S.E., and at Cape Adare S.E. At Framheim (see Birkeland, “Remarks on the 
Meteorological Observations,” Appendix II of The South Pole, by Roald Amundsen, vol. ii, 
pp. 372-94, London, 1912) the percentage frequency for the period April 1911 to January 
1912 was as follows : — 
N. N.E. E. S.E. S. S.W. W. N.W. Calm. 
2 8 32 7 12 14 2 1 22 
The percentage frequency was thus 7 with northerly winds, 40 with easterly, 22 with 
southerly, and 9 with westerly, calms being apparently much more frequent than at Cape 
Evans or Cape Adare. As, however, the winds at the two last-named stations were largely 
affected by local conditions, the results “ must be considered in the light of information 
which will be given in the discussion which is at present being written” (see Simpson, 
Quart. Jour. Boy. Met. Soc., vol. xl, pp. 224 and 226). For this reason it is unsafe to attempt 
to lay down the precise position occupied by the centre of the Ross Sea barometric minimum, 
which, doubtless, is subject, as are other “ action-centres,” to considerable variations from 
one year or season to another. 
t Scot. Geog. Jour., vol. xxvi, p. 413. 
