NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 3OI 



It has, however, to be considered that immediately to the east of 

 the Pacific States there is a comparatively very warm region in the 

 western United States, where the normal isobaric lines for the year 

 show comparatively low mean pressure, dividing between the North 

 Atlantic high-pressure region to the east, and the North Pacific high- 

 pressure region to the west. A shifting in the development and 

 extension of these centers of action might easily invert the effects 

 of the changes in atmospheric circulation in the temperature in these 

 boundary regions. We may therefore expect that the agreement 

 between the fluctuations in the temperature of the Pacific states, and 

 the fluctuations of the barometric centers of action are sometimes 

 inverted. This agrees with what we have already pointed out before 

 (cf. fig. 75). 



The region on the northern and northwestern side of the Mexi- 

 can Gulf is chiefly under the influence of the North Atlantic high 

 pressure center to the east, and an increase of the activity of this 

 center may therefore, during a great part of the year, afifect in- 

 creased easterly and southeasterly winds with a rise of tempera- 

 ture, and vice versa. The temperature curve VII (fig. iii) for the 

 Gulf states therefore show much similarity to the barometric curve 

 II for Ponta Delgada, and with the inverted barometric curve I for 

 Batavia. As, however, the Gulf states are in a barometric boundary 

 region these agreements may sometimes be inverted as, for instance, 

 in the years after 1901. 



At Cordoba, in Argentina, the normal isothermal lines for the year 

 go comparatively far south. This region has a comparatively warm 

 climate, being situated to the west of the South Atlantic high-pres- 

 sure center. A warm sea current is running southward outside the 

 coast. An increase of the activity of the South Atlantic center of 

 action may therefore be expected to increase the northeastern warm 

 winds, and to raise the temperature. The temperature curve VIII 

 (fig. Ill) for Cordoba shows, on the whole, agreement with the 

 barometric curve II for Ponta Delgada, and the inverted curve I for 

 Batavia, but the maxima and minima occur often later at Cordoba 

 than the corresponding maxima and minima in the other regions. 



On the east coast of Asia the normal annual temperature is com- 

 paratively low, owing to the situation to the east of the barometric 

 high-pressure center of inner Asia, causing much northerly wind 

 along this coast, while western Siberia, to the west of the Asiatic 

 high-pressure center, has much higher yearly temperatures, owing 

 to more southerly winds. Changes in the activity of the Asiatic 



