Appendix No. II
THE ANTARCTIC CLIMATE
BY
HENRYK ARCTOWSKI
The following is a preliminary account of some of the additions to our knowledge of the meteorology of higher southern latitudes contributed by the recent Belgian Antarctic Expedition.
These desolate antarctic regions, still so little explored, present many physical problems of the highest interest; the question of their climate, attacked as early as the time of Croll, must prove a subject of exhaustive investigation in the immediate future. The results I have obtained were not originally intended for publication in their present form, because the mean values involved can only be regarded as first approximations; however, it appears that my provisional numbers are sufficiently exact to indicate the general nature of the climatic régime in parts of the globe about which we have been, up to the present, practically without information. The fact that other antarctic expeditions are about to set out has decided me to publish my figures as they stand.
For the purposes of our inquiry, it is a matter of indifference whether an antarctic continent exists or not; we have undoubtedly to deal with a continuous surface of ice, which the meteorologist must regard as a land surface as opposed to an open sea. This ice-cap is entirely isolated by an ocean which surrounds it, and is subjected to the peculiar conditions of polar day and night. Hence the first points to be considered are the average distribution of pressure and the direction of the prevailing winds. The positions (about 81° and 95° west longitude, and 69° 50′ and 71° 30′ south latitude) show a relatively small distance from the open sea and great distance from the pole. In consequence we experienced two distinct types of climate according to the direction of the wind,—a continental and an oceanic,—in effect a coastal climate depending on the passage of cyclones which varied in frequency with the seasons. This seems to be the key of the whole position. As regards details, I take into consideration the mean and minimum temperatures and the barometric pressures, the direction of wind, the amount of cloud, and the amount of precipitation.
Table I. gives the mean values obtained from hourly observations of temperature made on board the Belgica during her drift in the ice.
July was the coldest month; its mean temperature was -23.5° C. (-10.3° F.), and the lowest temperature observed during the month, -37.1° C. (-34.8° F.). The extreme minimum of temperature was observed in September, -43.1° C. (-45.6° F.).
The warmest month was February, with a mean temperature of -1.0° C. (30.2° F.), and minimum for the month, -9.6° C. (14.7° F.).