THE WEDDELL QUADRANT AND ADJACENT AREAS. 113 



south as compared with the previous month. At Sandy Point, however, it falls to the 

 annual minimum. 



In October, pressure has fallen very generally west of the 55th meridian, but at 

 South Georgia and the South Orkneys it has increased. The east and west low- 

 pressure areas have become merged into one, whose centre is normally located over 

 Graham's Land, but which, judging from the winds at Port Charcot, is probably 

 frequently central to the W.N.W. 



Gradients are steep west of the 60th meridian, and gales are at a maximum on the 

 South Chilian coast and Cape Horn region, a relatively large number being from 

 the S.W. 



Temperature is now rising rapidly south of 60° S., the increase being most pro- 

 nounced at continental stations. The rise over Tierra del Fuego and adjacent islands 

 is remarkably uniform. The isotherms continue to open out and the thermal gradients 

 diminish. 



At Staten Island and Dungeness calms are at their annual maximum, a condition 

 offering a marked contrast to the stormy weather on the Pacific side of the straits. 



The rainfall has increased on the Pacific side of the Magellan Straits, but in lat. 

 40 S. on the Chilian coast the precipitation is only about half that of the previous 

 month. 



The changes shown in the isobaric chart for November are remarkable. Pressure 

 has risen greatly over Graham's Land, and to a less extent in the Bellingshausen Sea, 

 while it has fallen appreciably at the South Orkneys, South Georgia, and Tierra del 

 Fuego. An anticyclone is in process of formation on that portion of the Antarctic 

 continent to the south of the Bellingshausen Sea and far south of Graham's Land. 

 North-east winds prevail on the Pacific side of Graham's Land, and east and north-east 

 in the Bellingshausen Sea, where they blow with great strength. The cyclonic area 

 over the Wcddell Sea in this month is probably central about the latitude of the 

 Antarctic circle in 10° W., with the isobars tending to the north on proceeding east of 

 the meridian. In connection with this relatively higher pressure to the north, one may 

 note that during the summer voyage of the " Valdivia" the west wind system was left 

 behind in November in as low a latitude as 56° S. in 20° E., while east winds prevailed 

 to 65° S. between the meridians of 20° to 60° E. On the return voyage in December 

 the west winds were again experienced in lat. 55° S. 



While the position of the bottom trough on this voyage may have been located a 

 degree or two further north than usual, it is still highly probable that the general 

 condition is as described. That a great and widespread change of pressure distribution 

 is in progress is evident. Speaking broadly, the month to month changes of pressure 

 in Graham's Land and Tierra del Fuego are in the same direction, but in November, as 

 will be seen, they are not only the reverse of each other, but that to a very large 

 degree. Pressure has changed little at the Falklands, and has fallen much more 

 on the Pacific than on the Atlantic side of the straits, the result being steep 



