Ueber die allgemeine atmosphärische Zirkulation während der diluvialen Vereisungsperioden

Abstract

The range of polar cold air over the northern hemisphere was increased during the glacial periods primarily due to the extension of the large ice shields. Particulary in the northatlantic region the atmospheric centers of action and the storm tracks were shifted southwards, the meridional temperature gradient was strengthened and consequently the general circulation increased. This intensification of the large scale exchange of air does not contradict the recent increase of the general circulation and its consequences, since during the glacial periods the increase was of a compulsory and secondary nature caused by the ice extension itself. On the contrary the atmospheric circulation at the beginning of the glaciation must have been decreased. However, the continued extension of the Scandinavian ice shields, as well as the creation of the Keewatin and Labrador shields in North America and the North Asian glaciation, occurred during periods of secondarily increased circulation. An examination of the most important Ice age theories shows that the primary weakening of the circulation may be satisfactorily explained only by assuming a decrease of the earth's solar radiation supply. The astronomical Ice age theory is applicable only in connection with the assumption of an uplift of the Iceland-Faerisland submarine ridge.