The riddles of foehn - introduction to the historic articles by Hann and Ficker
Two key papers on the topic of foehn are introduced. The first one, published in 1885 by Julius Hann, discusses the history of the “thermodynamic foehn theory, and the role of the various scientists who contributed to its evolution. Emphasis is placed on the early recognition of important aspects by J. P. Espy which was not properly recognised in Europe at the time of publication (around 1850). Hann's article is very interesting also because it permits insight into the role of social factors for the acceptance of scientific theories, involving two of the most important meteorologists of the 19th century, W. Dove and J. Hann himself. The second paper was published in 1910 by Heinrich Ficker and discusses theories for the process of foehn break-through which are evaluated on the base of Ficker's mesonet in the area of Innsbruck and surroundings. Finally, the most important developments in foehn research in the past 100 years, since the appearance of Ficker's article, are very briefly sketched.