Temperature and precipitation variability in Italy in the last two centuries from homogenised instrumental time series
Article first published online: 25 JAN 2006
Copyright © 2006 Royal Meteorological Society.
International Journal of Climatology
Volume 26, Issue 3, pages 345–381, 15 March 2006
How to Cite
Brunetti, M., Maugeri, M., Monti, F. and Nanni, T. (2006), Temperature and precipitation variability in Italy in the last two centuries from homogenised instrumental time series. Int. J. Climatol., 26: 345–381. doi: 10.1002/joc.1251
- Issue published online: 21 FEB 2006
- Article first published online: 25 JAN 2006
- Manuscript Accepted: 30 JUN 2005
- Manuscript Revised: 5 MAY 2005
- Manuscript Received: 7 FEB 2005
- data homogenisation;
- trend analysis;
- monthly temperature records;
- monthly precipitation records;
- minimum and maximum temperature;
- daily temperature range
The Italian monthly temperature (mean, maximum and minimum) and precipitation secular data set was updated and completely revised. Station density and metadata availability were greatly improved and the series were subjected to a detailed quality control and homogenisation procedure. The data homogenisation is described in detail. The bias affecting original data is quantified by studying the temporal evolution of the mean adjustments applied to the series and examined in the light of the stations history. The results stress the importance of homogenisation in climate change studies.
The final data set was clustered into climatically homogeneous regions by means of a Principal Component Analysis. Yearly and seasonal trend analyses were performed both on regional average series and on the mean Italian series. The results highlight a positive trend for mean temperature of about 1 K per century all over Italy; it is generally higher for minimum temperature than for the maximum temperature. The progressive application of trend analysis shows that, in the last 50 years, behaviour is the opposite; the maximum temperature trend being stronger than that of the minimum temperature. This has led to a negative trend in the daily temperature range that for the last 50 years has become positive. Precipitation shows a decreasing tendency, even if low and rarely significant, the negative trend being only 5% per century on a yearly basis. Copyright © 2006 Royal Meteorological Society.