Rainfall over the Central-Western Mediterranean basin in the period 1951-1995. Part I: precipitation trends

Climatic changes due to the anthropic enhancement of the greenhouse effect could modify the hydrological cycle, resulting in a reduction of the precipitation over the Mediterranean basin. In particular, a negative trend over the Italian peninsula could occur with prolonged periods of dryness as that recorded in the biennium 1988-1990. In order to verify if a climatic variability is already detectable, the pluviometric regime over the Central-Western Mediterranean is here analysed for the period 1951-1995. The analysis indicates that a reduction of about 20% in the total precipitation has occurred, which is statistically significant and can have serious impact on the availability of the water supplies

Summer air temperature anomalies in Europe during the century 1811-1910

Solar cycle, volcanic eruptions, sea surface temperature anomalies (ENSO) and increase of the concentration of the greenhouse gases are the main forcing factors in the evolution of the Earth climate. Therefore, a sizeable amount of research is devoted to assess the impact of these factors on the climate parameters, as the mean air temperature. In the present work a study concerning the behaviour of the summer temperatures over Europe during the century 1811-1910 is carried out. The possible influence of the volcanic eruptions and ENSO has been also analysed. The results show the presence of a volcanic signal in the summer temperature during the year following an eruption, even if the anomalous coldest summers do not seem to be driven by the volcanic activity. The connection between thermal anomalies and ENSO events is more uncertain because of the paucity of data. Finally, the anomalous summers—both very cold and very warm—can be explained in terms of the atmospheric circulation, since cold events seem to be associated to persistent blocking systems and warm events are associated to persistent high-pressure patterns

Thermally forced mesoscale atmospheric flow over complex terrain in Southern Italy

In this paper we discuss some results concerning the analysis of the local atmospheric flow over the southern part of Italy, the Calabria peninsula, using a mesoscale numerical model. Our study is focused on two different but related topics: a detailed analysis of the meteorology and climate of the region based on a data collection, reported in Colacino et al., Elementi di Climatologia della Calabria, edited by A. GUERRINI, Collana P. S., Clima, Ambiente e Territorio nel Mezzogiorno (CNR, Roma) 1997, pp. 218, and an analysis of the results based on the simulated flow produced using a mesoscale numerical model. The Colorado State University mesoscale numerical model has been applied to study several different climatic situations of particular interest for the region, as discussed in this paper. In particular, the effects on the circulation over the region, due to the variation of different physical parameters as large-scale flow intensity, vertical potential temperature gradients, soil moisture, have been studied, and the seasonal variability of the Thermally Forced Mesoscale Circulations (TFMCs) is presented. The results show that thermally forced mesoscale circulation in the region is rather complex, and more pronounced than in regions located at the same latitude. The cells are strongly supported by the presence of the two breeze systems (sea-land and mountain-valley), and their location, shape and intensity are affected by the intensity of the large-scale flow, while atmospheric stability and soil moisture have a weaker influence on the TFMC structure. This study of the dynamics and thermodynamics of the atmosphere in this region, and particularly the analysis of the wind field, is preliminary for other related topics of research as agrometeorology, wind energy exploitation, environmental impact assessment, and for research related to tourism

Influence of climatic variables on crown condition in pine forests of Northern Spain

Producción CientíficaThe aim of this study was to find relationships between crown condition and some climatic parameters to identify which are those having a main influence on crown condition, and how this influence is shown in the tree (crown transparency), and to contribute to the understanding of how these parameters will affect under future climate change scenarios

Bioclimatic analysis in a region of southern Italy (Calabria)

In this study, an analysis of precipitation and temperature data has been performed over 67 series observed in a region of southern Italy (Calabria). At first, to detect possible trends in the time series, an analysis was performed with the Mann–Kendall non-parametric test applied at monthly and seasonal scale. An additional investigation, useful for checking the climate change effects on vegetation, has also been included analysing bioclimatic indicators. In particular, Emberger, Rivas-Martinez and De Martonne indices were calculated by using monthly temperature and precipitation data in the period 1916–2010. The spatial pattern of the indices has been evaluated and, in order to link the vegetation and the indices,different indices maps have been intersected with the land cover data, given by the Corine Land Cover map. Moreover, the temporal evolution of the indices and of the vegetation has been analysed. Results suggest that climate change may be responsible for the forest cover change, but, given also the good relationship between the various types of bioclimate and forest formations, human activities must be considered

Detailed Analysis of Solar Ultraviolet-radiation - A Preliminary Investigation On Data Collected At Rome (la-sapienza-university)

The importance of solar ultraviolet radiation and its impact on human health is well known by the scientific community. Variations of the ozone layer can influence the UV radiation reaching the Earth's surface, especially at short wavelengths. Thus, it is important to study any possible ozone fluctuations. At the Physics Department, University of Pome, a Brewer spectrophotometer MKIV is located and is used to measure total ozone and UV flux in the 290-325 nm region with a resolution of 0.5 nm. Measurements of damaging ultraviolet radiation (DUV), defined as the incident radiation weighted against an action spectrum which relates the sensitivity of the human body to UV radiation, are also processed. This work is a preliminary investigation on the spectral solar UV radiation measurements performed at Rome during the years 1992/1993