1. Trends of mean and extreme temperature indices since 1874 at low-elevation sites in the southern Alps
- Author
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L. Mercalli, Renate Auchmann, Yuri Brugnara, Alessio Bozzo, Daniele Cat Berro, and Stefan Brönnimann
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Cloud cover ,0208 environmental biotechnology ,Climate change ,02 engineering and technology ,Hot days ,Heat wave ,01 natural sciences ,Extreme temperature ,020801 environmental engineering ,Geophysics ,13. Climate action ,Space and Planetary Science ,Climatology ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Mean radiant temperature ,0105 earth and related environmental sciences - Abstract
We describe the recovery of three daily meteorological records for the southern Alps (Domodossola, Riva del Garda, and Rovereto), all starting in the second half of the nineteenth century. We use these new data, along with additional records, to study regional changes in the mean temperature and extreme indices of heat waves and cold spells frequency and duration over the period 1874–2015. The records are homogenized using subdaily cloud cover observations as a constraint for the statistical model, an approach that has never been applied before in the literature. A case study based on a record of parallel observations between a traditional meteorological window and a modern screen shows that the use of cloud cover can reduce the root-mean-square error of the homogenization by up to 30% in comparison to an unaided statistical correction. We find that mean temperature in the southern Alps has increased by 1.4°C per century over the analyzed period, with larger increases in daily minimum temperatures than maximum temperatures. The number of hot days in summer has more than tripled, and a similar increase is observed in duration of heat waves. Cold days in winter have dropped at a similar rate. These trends are mainly caused by climate change over the last few decades.
- Published
- 2016