Errors in Early Temperature Series Arising from Changes in Style of Measuring Time, Sampling Schedule and Number of Observations

Study of the Padova series (1725–today) is a useful example, of general interest, of a critical revision of long time series. These are composed of a number of inhomogeneous parts, each of them with mean daily values, and extremes, computed in different ways, based on observations taken at different times, or with the time expressed in different styles. Imprecise clocks, little care for the schedule established for meteorological readings, changing style of evaluating time, inappropriate choice of observing schedules, too small a number of readings to compute the daily average, generated errors that caused significant departures in time series, that could be interpreted as a climate signal. In the past, average values were obtained with only a few daily measurements. The first problem is to correct the data and extrapolate the hourly temperatures needed to evaluate the daily minimum, maximum and average values in a homogeneous way. The change of style in temporal reference introduced spurious seasonal changes. Styles (or combinations of styles) used were: Italian time in use till 1789, in which the hours werecomputed starting from twilight; apparent solar time based on theactual motion of the sun; mean solar time based on the average motion of the sun; local time referred to the actual passage of thesun across the local meridian (local culmination); French timestarting at midnight and regulated on the local culmination; Western European Time regulated on theculmination of fictitious average solar motion on a reference meridian 15° East. A test was performed to verify whether the times chosen for readings were appropriate, in particular when observations were performed not close to the daily minimum and maximum. In effect, in the early period with Morgagni and Toaldo, the choice of schedule of observations was good, but afterwards the introduction of new observations, not always established at the most appropriate schedule, reduced the representativity of the data. The error in calculating the daily average temperature after a given number of observations taken at different hours of the day has been analysed. National, and especially international recommendations have been particularly important in the choice of observations times, and in determining averages. These recommendations have been simultaneously applied on a large number of sites, causing an in-homogeneity that may be misinterpreted as a well-documented, widespread climate change.     

Instrumental seismological data since 1900 for northeastern Italy

Statistical analyses on a catalogue of instrumental data for earthquakes in northeastern Italy since 1900 are presented. The different types of magnitude, which are the main parameters under study, have been evaluated so as to be as homogeneous as possible. Comparisons of the different magnitude values show linear dependence, at least in the medium magnitude range represented by the available data set. Correlations between the magnitude most significant for this region and chosen macroseismic data indicate a methodology for assessing the macroseismic magnitude of historical earthquakes which seems to be stable.     

Different approaches to the seismic hazard of Sannio-Matese (Southern Italy)

The seismic hazard of Sannio-Matese is calculated using a new seismogenetic zoning of southern Italy of seven areas and different, azimuth-dependent, attenuation laws. Various approaches (Gumbel's first and third asymptotic distribution, Cornell) lead to similar results for the different exposure times considered (100 and 200 years) and probability levels (37 and 68%). The present seismic regulation proposed in 1980 by the Italian National Council for Researches, and based on a different approach, is, in general, confirmed by the results.     

Seismic behaviour of girder bridges for horizontally propagating waves

The results obtained from a parametric study on the influence of horizontally propagating waves for the earthquake behaviour of continuous girder bridges are presented. The investigation is performed for floating-supported bridges excited by an earthquake acting in their vertical planes. The shallow foundations are assumed to be supported on the surface of either a visco-elastic halfspace or a visco-elastic layer resting on an elastic halfspace. Steady-state response for harmonic excitation and transient response for an artificial time history are investigated. Approximate equations describing the influence of horizontally propagating waves are presented and criteria are derived indicating when an increase of the internal forces and of the relative motion between the girder and the abutments can be expected.     

Freezing of the Venetian Lagoon since the 9th century A.D. in comparision to the climate of western Europe and England

In the first part of this study, typical of historical climatology, the various sources regarding freezing of the Venetian Lagoon since the 9th century A.D., are reported and discussed. The events are related, where possible, to teleconnections. Two synoptic patterns (weather type A: northerly and D: easterly) seem to have played an important role. After having discussed the dynamics of the icing processes, the problem of comparing the data is considered, as over the centuries many works were made on the Lagoon, in order to divert the major tributaries. In fact, the hydrological regime and the physical characteristic of the Lagoon environment were changed, so that the conditions necessary for freezing were no longer the same. The series was compared with the severe winters in westtern Europe and England, in order to reconstruct the past climate of the Mediterranean region and discuss the observed secular changes in the light of the widely accepted ideas of climatic variations. The comparison shows some differences: e.g. at Venice the Medieval Climatic Optimum with the occurrence of severe winters ended earlier and the Little Ice Age was broken by a milder interval.     

A multiscale observational case study of an isolated tornadic supercell

This work deals with the analysis of an isolated tornadic supercell thunderstorm that took place on the plain of Friuli Venezia Giulia (Italy) causing several damage. The analysis is performed using different kind of data, looking in the available information for possible signatures that could be helpful in the forecasting and nowcasting procedures. The analysis reveals that rather than a single cause for the tornadic storm development, there is an “interaction” of several effects. In particular, a favorable environment seems to be produced by the interplay between synoptic and mesoscale environments with a fundamental role played by orography. Radar data, in particular Doppler measurements, are fundamental to the recognition and interpretation of the events but in this particular case they could give little useful information for the forecasting and nowcasting procedures. The most robust signals of an environment prone to the onset of severe deep moist convection come from the thermal gradients at the ground and by the vertical profile analysis. The reason why the event took place in that specific place and not in others is still unknown.     

Entering the cosmic ray precision era

Here we outline some recent activities in the theory and phenomenology of Galactic cosmic rays, in the light of the great precision of direct cosmic ray measurements reached in the last decade. In the energy domain of interest, ranging from a few GeV/nucleon to tens of TeV/nucleon, data have revealed some novel features requiring an explanation. We shall emphasize the importance of a more refined modeling, of achieving a better assessment of theoretical uncertainties associated to the models, and of testing key predictions specific of different models against the rich datasets available nowadays. Despite the still shaky theoretical situation, several hints have accumulated suggesting the need to go beyond the approximation of a homogeneous and non-dynamical diffusion coefficient in the Galaxy.     

Revisited Formulation and Applications of FFT Moving Average

Mathematical Geosciences - The fast Fourier transform-moving average (FFT-MA) is an efficient method for the generation of geostatistical simulations. The method relies on the calculation of a...     

Thermodynamic exchanges between the external boundary layer and the indoor microclimate at the Basilica of Santa Maria Maggiore, Rome, Italy: the problem of conservation of ancient works of art

The Basilica of Santa Maria Maggiore, Rome, is an example of how ancient buildings with thick walls lessen the impact of the external temperature and humidity variations. The external influence on the internal microclimate is studied in order to gather information on how the building exchanges heat and moisture. Correlations between outdoor and indoor values are found. The results are applied to the calculation of the condensation-evaporation cycles inside micropores due to the Kelvin effect, to assess their impact on works of arts placed inside and outside the Basilica. It was found that the building attenuation is not sufficient to avoid damage due to condensation-evaporation cycles on stones and plasters. Some suggestions are made in order to mitigate the temperature variations during the liturgical offices.