Early instrumental meteorological measurements in Switzerland

Abstract

Abstract. The decadal variability of weather and its extremes are still poorly understood. This is partly due to the scarcity of records, which, for many parts of the world, only allow for studies of 20th century weather. However, the 18th and early 19th centuries saw some pronounced climatic variations, with equally pronounced impacts on the environment and society. Considerable amounts of weather data are available even for that time but have not yet been digitised. Given recent progress in the quantitative reconstruction of subdaily weather, such data could form the basis of weather reconstructions. In Switzerland, measurements before 1864 (the start of the national network) have never been systematically compiled except for three prominent series (Geneva, Basel, Great St. Bernard Pass). Here we provide an overview of early instrumental meteorological measurements in Switzerland resulting from an archive survey. Our inventory encompasses 334 entries from 206 locations, providing an estimated 3640 station years and reaching back to the early 18th century. Most of the data sheets have been photographed and a considerable fraction is undergoing digitisation. This paper accompanies the online publication of the imaged data series and metadata. We provide a detailed inventory of the series, discuss their historical context, and provide the photographed data sheets. We demonstrate their usefulness on behalf of two historical cases and show how they complement the existing series in Europe. If similar searches in other countries yield similarly rich results, an extension of daily weather reconstructions for Europe back to the 1760s is possible.

Statistical reconstruction of daily precipitation and temperature fields in Switzerland back to 1864

“…Could daily reconstructions be extended even further back in time? For Switzerland, a recent survey brought to light a large amount of early instrumental data (Pfister et al, 2019). An extension of the dataset to the pre-industrial period is therefore envisaged, although larger measurement errors and less consistent measurement series make this endeavour rather challenging.…”

“…As pointed out by Cannon (2018), this procedure is asynchronous; that is, it does not consider any chronological aspects of precipitation. In its simplest application, QM corrects the model bias according to observed precipitation values (Piani et al, 2010) and can be generally expressed by Eq. 8:…”

“…Precipitation values beyond 0.1 mm were set to zero. Parametric transfer functions were calculated from all data within the calibration period 1 January 1961-31 December 2017 for each grid cell after Piani et al (2010), with P m the values from the analogue reconstructions and P o the values from the RhiresD dataset. No discrimination between different seasons has been made.…”

Synthetic Weather Diaries: Concept and Application to Swiss Weather in 1816

“…The gridded reconstruction is based only on instrumental measurements from three stations. In a recent project we have uncovered (Pfister et al, 2019) and digitized (Brugnara et al, 2020) many more instrumental series for Switzerland back to the early 18th century, such that we now have ten series for 1816. This effort was part of a global effort to uncover more historical instrumental data (Brönnimann et al, 2019b), a lot of which is currently being digitized.…”

“…Further weather-related effects were related to snow accumulation, such as avalanches in the following winter (Rohr, 2015) and a flood event in early summer 1817, although the snowmelt contribution was large only close to the Alps (Rössler and Brönnimann, 2018). The Tambora eruption was one of at least five large eruptions within a relatively short period, which together had profound effects on the global climate system, including monsoons, and on Alpine glaciers (Brönnimann et al, 2019).…”