Historical reconstruction climate variability and change in Mediterranean regions

In the frame of “US-Italy cooperation on Science and Technology of climatic change”, sponsored by INGV, we organized a meeting focusing on decadal climate variability in the Mediterranean regions in the context of long-term climate change. Our aim is to assess past climate variability using historical climate reconstructions and sources in the Mediterranean region both of western US and southern Europe. This report summarizes some key aspects of climate variability in the Mediterranean region in the past 200 years and identifies uncertainties and unresolved scientific questions still open for further research

Cosmic rays 10Be biennal data and their relationship to aurorae and sunspots

The galactic cosmic ray (C.R.) variations which should give information on three dimensional aspects of the heliospheric magnetic fields and on the solar wind, which modulate their influx into the Solar System were studied. In order to decode the information from the C.R. series it is necessary to know the mechanisms through which the modulation is produced. It it clear that a balance of effects with sources at different heliospheric latitudes results in the modulated C.R. intensity. It is found that the modulation of 10Be in polar ice may be due to at least two main contributions: (1) negative and in phase with the Solar flare activity modulating the cosmic ray flux in Forbush-type decreases, and (2) positive in phase with the appearance of large wind streams situated at both polar coronal holes. It is found that the high heliolatitude activity is related to a stable periodicity of 11.1y whereas the low heliolatitude activity contributes to the wondering of the solar cycles

Cosmic ray secular variations in terrestrial records and aurorae

The rediscovery that the Sun and the solar wind can undergo important changes on historical time scales has brought into question the stability of the cyclic behavior of past time series of solar and solar-terrestrial origin. It was found by Vector Fourier analysis that the solar 11 year cycle is present in the series of 10Be, delta 180, in ice cores and of thermoluminescence (TL) in sea sediments during the last Millennia with a frequency modulation, related to the Sun behavior, as tested by comparison with the Sunspot number R sub z series. It was shown that the cyclogram of the series of yearly Aurorae from 1721 to 1979 linear-regression-corrected-for-R sub z is straight for the periodicity zeta=11,1y, which indicates that such periodicity is constant in time corresponding to the only line present in the 11y band. The maxima of this component appear at the same time together with the high speed solar wind streams taking place in coronal holes situated in high heliolatitudes. It is evidenced that the 11 year cycle has undergone frequency oscillations on a time scale of two centuries, although it is very difficult to determine the periodicities with high accuracy

Study of the solar signal in mean Central Europe temperature series from 1760 to 1998

We used a new series, highly reliable and representing the mean surface temperature of Central Europe for the period 1760-1998, to study Sun-Climate relationships. The results indicate that the influence of solar activity is evident only on a long time scale, in particular for the period 1860-present. On a short time scale it is not directly evident. From the spectral analysis we deduced that the strength of solar signal in the temperature series has an intermittent behaviour. We proposed a mechanism of resonance between the two non-linear systems, the Sun and Earth climate, to explain our results

Development of new FRP reinforcement for optimized concrete structures

With the goal of achieving sustainable design, being able to combine optimized geometries with durable construction materials is a major challenge for Civil Engineering. Recent research at the University of Bath has demonstrated that fibre-reinforced polymers (FRP) can be woven into geometrically appropriate cages for the reinforcement of optimised concrete beams. This innovative construction method enables the replacement of conventional steel with non-corrosive reinforcement that can provide the required strength exactly where needed. The manufacturing of the reinforcement is achieved by means of an automated process based on a filament winding technique. Being extremely lightweight, the wound-FRP (WFRP) cages are well suited to speeding up construction processes, as they can be delivered on site ready to be cast. In this paper, the results of flexural tests on optimised full-scale flexibly formed concrete elements are reported and discussed. Two different case studies are taken in consideration: A structurally optimized joist supporting a lightweight floor;A structurally optimized beam with an in-situ casting of a concrete floor. The optimization objective is to obtain the minimal mass of concrete required to achieve the structural capacity design requirements from widely recognized design codes. The experimental results demonstrate the reliability of the technical solution proposed and provide the basis of a new concept for sustainable and durable reinforced concrete structures

The Italian air force sea level pressure data set (1951-2000)

A set of 39 homogenised sea level pressure records, extracted from the Italian Air Force dataset (1951-2000), is introduced and analysed for trends. The data consist of 3-hourly observations. Daily mean pressures are obtained using a method that allows biases to be avoided due to the presence of a high fraction of days that do not have all 8 observations. Trend analysis is performed on seasonal and yearly basis and concerns both the individual station records and the series of their averages. The results show a highly significant positive trend in winter and yearly air pressure all over Italy. It is mainly due to a change-point around 1980. The Italian air pressure records are also compared with the NCAR/NCEP and UKMO gridded data sets. The results give evidence that gridded data capture most of the trend and variability of air pressure over Italy, even if NCAR/NCEP data display some significant inhomogeneities with respect to the station records

Extreme summer temperatures in Western Europe

Abstract. We discuss the evolution of summer temperature extremes over Western Europe during 1961–2004 in the context of current climate warming. Using a parametric approach, we investigate the role of properties and changes in probability density functions of daily temperatures in modifying the frequency of severe, isolated events. In this perspective, the recent intensification of extremely warm events over Europe turns out to be well consistent with a pure, nonuniform shift of mean values, with no room for conjectures about increasing temperature variability

Early invasive strategy (< 24 hours) in patients with acute coronary syndromes: Weighing the evidence

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