Publications of Pfister, C.
Daily Weather Observations in Sixteenth-Century Europe
Thirty-two weather diaries written in astronomical calendars in central Europe in the late fifteenth and sixteenth centuries are presented and discussed. Systematic weather observations were promoted by the rise of planetary astronomy and its application in astro-meteorology. The practice of keeping weather diaries spread from Cracow (Poland) to Ingolstadt (Germany) and from there to other universities. The data obtained from these sources provided the backbone for setting up series of precipitation indices for Poland, Germany and Switzerland. Monthly statistics of days with precipitation, snowfall and frost were computed by counting the relevant entries in the most important diaries. The results were compared with either those obtained from instrumental measurements in the same place or with those from modern instrumental measurements in a neighbouring place. The final results show that autumn was considerably colder in the early sixteenth century. April was considerably drier and July was wetter during the period 1508-1531 than during 1901-1960. In order to highlight the impact of weather patterns on grain prices in a year of crisis, the timing of wet and dry spells in southern Poland and southern Germany is compared for the year 1529. Winters became 1.7°C colder from 1564 to 1576 and the month of July tended to be wetter than in 1901-1960. Details noted in the diaries kept between 1585 and 1600 by the astronomers Brahe (near Copenhagen) and Fabricius (in the Ostfriesland region of northwestern Germany) closely agree. It rained more often in June and July and temperatures dropped. The winter months were more frequently dominated by winds from easterly directions, the frequency of snowfall was higher and a deficit occurred in precipitation. This points to a higher frequency of high pressure in the Fennoscandian area with cold air advection from the east or northeast.
Documentary Evidence on Climate in Sixteenth-Century Europe
The known documentary climatic evidence from six European countries – Switzerland, Germany, the Czech Republic, ancient Hungary, Italy and Spain – is presented and classified in this article and then further analyzed in subsequent papers included in this volume. The sixteenth century witnessed an increase in the number and variety of sources in Switzerland, Germany and the Czech Republic as well as in the western and northern parts of ancient Hungary (present Slovakia). In northern Italy, the relevant sources are more abundant and widespread than in central Europe, but they have hardly been explored. Town chronicles written by members of the literate elite comprise the basic type of evidence in central Europe (including northern Italy and Hungary). This kind of source reports exceptional climatic events (e.g. anomalies and natural disasters) along with their impact on the environment and on society. Documentary data are the only evidence known to exist for reconstructing time series of natural disasters prior to the twentieth century. In order to document the extreme character of an event, chroniclers frequently referred to features in the cryosphere, biosphere or hydrosphere that were known to be more accurate yardsticks of temperature and precipitation patterns than subjective impressions. When records of such events are compiled with the description of some of the known effects, the results can be transformed into a severity index. Whereas chroniclers usually focused upon extreme events, long, continuous and seemingly homogeneous series of different kinds of proxy data are drawn from administrative records. Most of them are connected to the timing of certain kinds of agricultural work (hay-making, beginning of grain harvest or vintage) or to the amount and quality of agricultural production (per hectare yield of vineyards, sugar content of wine, etc.). In most cases the timing of these works was found to be directly related to temperature patterns over the preceding months and weeks.All the Iberian peninsula towns, which had an institutionalized municipal authority, have preserved documents generated from the late Middle Ages. These records frequently contain references to floods and meteorological anomalies such as droughts and long wet spells. They also include mention of the system of rogations, those religious rites performed in a standardized way within the Spanish world with a view to putting an end to an alleged meteorological stress.The data for Switzerland, Hungary and Spain as well as much of the data for Germany are stored in the EURO-CLIMHIST database set up at the Institute of History at the University of Bern. At present, EURO-CLIMHIST comprises some 600,000 data for the period from AD 750 to the beginning of the period of instrumental networks. About 120,000 records for Germany are currently stored in a data bank called HISKLID located at the Department of Geography of the University of Würzburg. The database for the Czech Republic includes records for the time-span AD 975-1900 and is housed with the Department of Geography of Masaryk University in Brno. Data on Italy were collected with different purposes and are stored in two data banks, the CNR-ICTIMA (climatic data and natural disasters) and the SGA (extreme events).