High resolution climate precipitation analysis for north-central Italy, 1961–2015
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Observational daily precipitation data from a group of 1762 stations over north-central Italy and adjacent areas are used to produce a high resolution daily gridded precipitation analysis covering the period from 1961 to 2015. Input data are checked for quality, time consistency, synchronicity and statistical homogeneity and the final result has been used to describe the spatial and temporal variability of precipitation over the area. Data are interpolated using a modified Shepard scheme and the interpolation errors are compatible with those presented in Isotta et al. (Int J Climatol 34(5):1657–1675, 2014). The analysis is compared with other similar products available over the area considered, and differences and similarities are described, taking into account the impacts of different spatial resolution and time coverage. The data set is used to describe local climate with respect to precipitation, including mean values and seasonality, by using a group of climate annual and seasonal indices: cumulated precipitation, maximum number of consecutive dry days, frequency of wet days, mean precipitation intensity and 50th and 90th percentile of daily precipitation over a season. The linear trends over the full period of these indices are described and compared. It is shown that although the time series of area average total annual precipitation over north-central Italy does not show significant linear trends, these are present locally. In particular, significant negative trends of annual total precipitation are found in central Italy and in the inner part of northern plains, while significant positive linear trends are present in several areas over the Alps and over the Liguria coast. The seasons most affected by changes in precipitation are summer and autumn, which, in most areas, are the driest and wettest seasons. In summer, significant positive trends in total precipitation have been found in areas close to the northern national borders, while significant negative trends are located elsewhere. The number of wet days is significantly decreasing over most of the domain, but the 90th percentile of precipitation is significantly increasing over most of the Alpine area and northern Po Valley. Over the southern part of the Po Valley and central Italy summer precipitation is significantly becoming less frequent and, generally, less intense. In autumn, total precipitation is characterised by significant positive trends over large areas in Northern Italy and by significant negative trends in inner areas of the Central Apennines. The trend patterns present great similarities with those of the 90th percentile of daily precipitation for the same season. The maximum length of dry spell is significantly decreasing in autumn over most areas, including central Italy, while the number of wet days presents negative but mostly non significant trends over the whole domain.
We thank Météo-France, MeteoSwiss, the Zentralanstalt für Meteorologie und Geodynamik (ZAMG) and the Meteorological Service of Slovenia for making available to the ARCIS consortium daily precipitation data for the period 1960–2015 at several stations close to the Italian border. We acknowledge the use of E-OBS dataset from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECAD project (http://www.ecad.eu). We thank Regione Friuli Venezia Giulia - Servizio Gestione Risorse Idriche, Agenzia Regionale per la Protezione dell’Ambiente della Valle d’Aosta and Agenzia Regionale per lo Sviluppo e l’Innovazione del settore Agricolo forestale della Toscana for providing part of the daily observational data used within this work. Finally, we thank three anonymous reviewers for helping us to improve the quality of this paper.
- Alexander LV, Zhang X, Peterson TC, Caesar J, Gleason B, Klein Tank AMG, Haylock M, Collins D, Trewin B, Rahimzadeh F, Tagipour A, Rupa Kumar K, Revadekar J, Griffiths G, Vincent L, Stephenson DB, Burn J, Aguilar E, Brunet M, Taylor M, New M, Zhai P, Rusticucci M, Vazquez-Aguirre JL (2006) Global observed changes in daily climate extremes of temperature and precipitation. J Geophys Res 111:D05109. https://doi.org/10.1029/2005JD006290 Google Scholar
- Casanueva A, Kotlarski S, Herrera S, Fernández J, Gutiérrez JM, Boberg F, Colette A, Christensen OB, Goergen K, Jacob D, Keuler K, Nikulin G, Teichmann C, Vautard (2016) Daily precipitation statistics in a EURO–CORDEX RCM ensemble: added value of raw and bias-corrected high-resolution simulations. Clim Dyn 47:719–737CrossRefGoogle Scholar
- Catellari S, Artale V (eds) (2009) I cambiamenti climatici in Italia: evidenze, vulnerabilità e impatti. Bononia University Press, Bologna, ItalyGoogle Scholar
- Giorgi F, Jones C, Asrar GR (2009) Addressing climate information needs at the regional level: the CORDEX framework. WMO Bull 58(3):175–183Google Scholar
- Giorgi F, Coppola E, Solmon F, Mariotti L, Sylla MB, Bi X, Elguindi N, Diro GT, Nair V, Giuliani G, Cozzini S, Güttler I, O’Brien TA, Tawfik AB, Shalaby A, Zakey AS, Steiner AL, Stordal F, Sloan LC, Brankovic C (2012) RegCM4: model description and preliminary tests over multiple CORDEX domains. Clim Res 52:7–29CrossRefGoogle Scholar
- Isotta FA, Frei C, Weilguni V, Percec Tadic M, Lassegues P, Rudolf B, Pavan V, Cacciamani C, Antolini G, Ratto SM, Munari M, Micheletti S, Bonati V, Lussana C, Ronchi C, Panettieri E, Marigo G, Vertacnik G (2014) The climate of daily precipitation in the Alps: development and analysis of a high-resolution grid dataset from pan-Alpine rain-gauge data. Int J Climatol 34(5):1657–1675CrossRefGoogle Scholar
- Pavan V, Antolini G, Agrillo G, Auteri L, Barbiero R, Bonati V, Brunier F, Cacciamani C, Cazzuli O, Cicogna A, De Luigi C, Maraldo L, Marigo G, Millini R, Panettieri E, Ratto S, Ronchi C, Saibanti S, Sulis A, Tomei F, Tomozeiu R, Torlai I, Villani G (2013) The ARCIS project. Ital J Agrometeorol 2(2013):51–55Google Scholar
- USGS-United States Geological Survey (1996) GTOPO30 documentation. http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/gtopo30_info