Bergen Synoptic School

Abstract

During the late nineteenth century, remarkable advancements were achieved in the field of atmospheric measurement systems, particularly through the implementation of direct aerological sounding techniques. Subsequently, starting from 1900, these measurements have been conducted consistently under the auspices of the International Aerological Commission. Concurrently, significant progress was also made in theoretical hydrodynamics, marking a new era in the evolution of theoretical meteorology. One of the notable pioneers in this domain was Wilhelm Freeman Bjerknes (1862–1951), who revolutionized the field with his renowned circulation theorem. In April 1897, Wilhelm Freeman Bjerknes discussed the circulation theorem with his students during theoretical physics classes at the University of Stockholm. He later published a preliminary version of the theorem in 1898, followed by its complete form in 1902. Notably, in 1896, Silberstein had already published one of the two circulation theorems in Krakow. However, Silberstein regarded the baroclinic state merely as a transitional phase, without delving into its practical implementation. In contrast, Bjerknes emphasized the application of the circulation theorem, establishing himself as the true inventor of this theorem due to his comprehensive exploration of its practical implications.

In April 1897, Wilhelm Freeman Bjerknes imparted his knowledge of the circulation theorem to his students during theoretical physics classes at the University of Stockholm. He initially published a preliminary version of the theorem in 1898, followed by its comprehensive form in 1902. It is worth noting that in 1896, Silberstein had already published one of the two circulation theorems in Krakow. However, Silberstein’s focus was primarily on the baroclinic state as a transitional phase, without discussing its practical implementation. In contrast, Bjerknes not only introduced the circulation theorem but also emphasized its real-world application. As a result, he can be regarded as the true originator of this theorem.