POLAR INFLUENCES ON WORLD WEATHER 33 



air. Almost simultaneously the pressure rises in high latitudes, 

 and an area of high pressure, accompanied by cold polar air, starts 

 toward the equator and gives rise to the "polar front" with its charac- 

 teristics of rain and wind. Following the center of high pressure a 

 body of warmer air presses poleward to meet a succeeding "polar 

 front" originating in the same way. 



These areas of high pressure form in certain favored regions of 

 the earth which were named by Teisserenc de Bort "centers of ac- 

 tion." One of these centers is in the Arctic Basin. Multanovskii^ 

 investigated the origin of the areas entering northern Europe and 

 found that those coming from the north and northeast came from the 

 Arctic basin north of Greenland and probably from the ice fields 

 beyond the pole. 



Simpson^" found that on the edge of the Antarctic Continent near 

 McMurdo Sound the pressure increased and decreased in an irregular, 

 wavelike manner, which he traced to a series of surges or pulses which 

 originated in the interior of the continent and were the causes of the 

 blizzards sweeping out from the mainland. 



Further investigations as to where and how these surges of pres- 

 sure originate are needed and may have a very important bearing on 

 the meteorology of the temperate zones. It may be that these surges 

 are due to the upsetting of the equilibrium of the atmospheric circu- 

 lation as a whole by changes in solar radiation, but observations 

 are needed to settle this point. 



Interrelation of Polar Ice Conditions, Atmospheric 

 Pressure, and Solar Radiation 



Another aspect of the polar problem is that of prolonged weather 

 conditions which make for favorable or unfavorable seasons. Wiese^^ 

 found that in years of abundant ice in August in Barents Sea the 

 pressure averaged above normal in June-July in northern Greenland 

 and to the north of Iceland (see Fig. 6). On the other hand when 

 there was a scarcity of ice in Barents Sea the pressure averaged high 

 over the North Atlantic south of Ireland (see Fig. 7). The question 



' B. P. Multanovskii: Osnovnyya polozheniya dlya deleniya Evropeiskoi Rossii na raiony 

 po vozdeistviyam polyarnogo tsentra deistviya atmosfery (The basic foundations for the division 

 of European Russia into regions according to the influence of the polar center of atmospheric action), 

 Izvestiya Glavnoi Fizicheskoi Ohservatorii, Pavlovsk, 1920, No. 3. [Abstracted in Petermanns Mitt. 

 Ergdnzungsheft No. 188, 1925, pp. 67-68.] 



1" op. cit.. Chapters 5 and 6. 



11 V. Y. Vize (W. J. Wiese) : O vozmozhnosti predskazaniya sostoyaniya Idov v Barentsovom 

 More (About the possibility of forecasting the ice conditions in Barents Sea), Izvestiya Tsentralnogo 

 Hidrometeorologicheskogo Byuro, Tsentralnoe Upravlenie Morskogo Transporta, Petrograd, 1923, 

 No. I. [Abstracted in Petermanns Mitt. Ergdnzungsheft No. 188, 1925, pp. 66-67.] 



idem (W. Wiese) : Die Einwirkung des Polareises im Gronlandischen Meere auf die Nordat- 

 lantische zyklonale Tatigkeit, Annal. der Hydrogr. und Marit. Meieorol., Vol. SO, 1922, pp. 271-280. 



idem: Polareis und atmospharische Schwankungen, Geografiska Annaler, Vol. 6, 1924, pp. 273-299. 



idem: Die Einwirkung der mittleren Lufttemperatur im Friihling in Nord-Island auf die mittlere 

 Lufttemperatur des nachfolgenden Winters in Europa, Meteorol. Zeitschr., Vol. 42, 1925, pp. 53-57. 



