S. Palmieri

Solar UV Dose Patterns in Italy

Abstract Since 1992 solar ultraviolet (UV) spectral irradiance (290–325 nm) has been measured at two Italian stations of Rome (urban site) and Ispra (semirural site) using Brewer spectrophotometry. The data collected under all sky conditions, are compared with the output of a sophisticated radiative transfer model (System for Transfer of Atmospheric Radiation—STAR model). The STAR multiple scattering scheme is able to cope with all physical processes relevant to the UV transfer through the atmosphere. The experience so far acquired indicates that, in spite of the unavoidable uncertainties in the input parameters (ozone, aerosol, surface albedo, pressure, temperature, relative humidity, cloud cover), measured and computed clear sky irradiances are in reasonable agreement. The STAR model is applied to build up the solar UV geographic patterns in Italy: the daily dose in the range 290–325 nm is computed at about 70 sites where a thorough and homogeneous climatology is available. For each month the concept of an idealized “standard day” is introduced and the surface distribution of solar UV field determined. The map of solar UV patterns for Italy, available for the first time, meets the study requirements in the field of skin and eye epidemiology, as well as in other investigations dealing with the impact of UV on the biosphere. The results are interpreted in terms of atmospheric and meteorological parameters modulating UV radiation reaching the ground.

Solar UV‐B irradiance and total ozone in Italy: Fluctuations and trends

Solar UV irradiance spectra (290–325 nm) together with daily total ozone column observations have been collected since 1992 by means of Brewer spectrophotometers at two Italian stations (Rome and Ispra). The available Brewer irradiance data, recorded around noon and at fixed solar zenith angles, together with the output of a radiative transfer model (the STAR model) are presented and analyzed. The Brewer irradiance measurements and total ozone fluctuations and anomalies are investigated, pointing out the correlation between the high-frequency O3 components and irradiance at 305 nm. In addition, the total ozone long time series of Arosa (170 km apart from Ispra) and Vigna di Valle (very close to Rome) are analyzed to illustrate evidence of temporal variations and a possible trend.

Tropical storm impact in Central America

In this study of tropical storm impacts in Central America, the relationship between physical variables (available in ‘real time’) and damage is explored, and a simple tool for early approximate evaluation of the impact is developed. Land track and energy dissipation appear as the most interesting parameters that modulate the hurricane impact. Because of the difficulty of attaching a monetary estimate to the damage caused in a large number of cases (as is required in a statistical approach), an ‘Impact Index’ based on the logarithm of casualties is introduced. Thereafter, within a subset of events in which damage in monetary terms is known, a rough link between damage and the Impact Index is derived. Shortly after a new event, as soon as land track and energy dissipation are known, either by means of an empirical equation or using a contour graph, the Impact Index may be determined. Another empirical equation allows a rough estimate of damage in monetary units, but because this estimate is based on a limited number of cases, it must be treated with caution. The methodology is tested for a small set of independent cases. Vulnerability to tropical cyclones depends not only on natural factors but also on sociopolitical conditions. A coupled sociological and environmental approach is believed to be the best way to improve the early impact estimate methodology. Copyright

Toward optimizing Brewer zenith sky total ozone measurements at the Italian stations of Rome and Ispra

A “sky chart” program for optimizing Brewer zenith sky total ozone measurements at Rome Station is developed. It is applied to total ozone data at the Rome station, obtained by both direct Sun and zenith sky methods for the period May 1991 to March 1993, to compute new polynomial coefficients used in the calculation of the zenith sky total ozone values. These new coefficients are then utilized by the program to compute new zenith sky total ozone values. The percentage differences between (1) the zenith sky measurements computed using the old coefficients and direct Sun ozone data and (2) the direct Sun and the zenith sky total ozone values obtained using the new coefficients are presented. The new coefficients are also applied to some zenith sky (ZS) ozone data of Ispra. The results of the comparison between new ZS and old ZS values with respect to the corresponding DS measurements are presented. The new coefficients give more optimized zenith sky total ozone values than the old ones.

In search of mountain sites suitable for wind farms in the Mediterranean area using a diagnostic wind model

A mesoscale diagnostic wind model, based on mass conservation, is utilised to develop a wind climatology for the southern Appennines in Italy, with the aim of identifying areas suitable for wind energy production plants. The model includes the kinematic effects of the high ground, anabatic and katabatic flows along mountain slopes as well as blocking effects. The climatological analysis carried out appears quite effective in selecting favourable areas where a more detailed investigation based on boundary layer models and observational field studies may lead to the final specification of locations suitable for mountain wind farms. Copyright

Detailed analysis of solar ultraviolet radiation: a preliminary investigation on data collected at Rome (‘La Sapienza’ University)

Abstract 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 Earths surface, especially at short wavelengths. Thus, it is important to study any possible ozone fluctuations. At the Physics Department, University of Rome, 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.

Investigation on Different Total Ozone Time Scale Components

Total ozone observations have been collected since 1992 by means of Brewer spectrophotometry at Rome (41.9°N, 12.5°E, 60 m a.s.l.) and Ispra (45.8°N, 8.63°E, 240 m a.s.l.). A filtering technique is applied to the Dobson ozone long time series of Vigna di Valle (42.08°N, 12.22°E, 262 m a.s.l.), Arosa (46.78°N, 9.68°E, 1840 m a.s.l.) and Lerwick (60.13°N, 1.18°W, 80 m a.s.l.) and to the Italian Brewer ozone data, in order to investigate on different time scales [1]. The aim of this analysis is to single out any effective ozone trend, together with the role of ozone fluctuations due to weather patterns, at the selected Northern Hemisphere middle latitudes sites.

UV Irradiance Patterns in Italy

Since 1992 the two Italian stations of Rome, urban site (latitude 41.9° N, longitude 12.5° E, altitude 60 m), and Ispra, semi-rural site (latitude 45.8° N, longitude 8.6° E, altitude 240 m), collect regular continuous measurements of spectral UV (290-325 nm) irradiance by means of Brewer Spectrophotometry. The measured data are compared with the output of the STAR model (System for Transfer of Atmospheric Radiation) [1]. STAR is a multiple scattering radiative transfer model which considers all atmospheric factors modulating UV radiation at ground (ozone, aerosol, clouds, pollutants, albedo, pressure, temperature, humidity) [2]. The model involves combination of a radiative transfer code, an initialisation procedure and an integration scheme.

An investigation of a possible dependence of Brewer number 67's total-ozone measurements on some atmospheric parameters, together with a presentation of a peculiar synoptic ozone case at Rome

SummaryBrewer total ozone data (January–December 1992) measured at the Physics Department, Rome University «La Sapienza» (41.9° North, 12.5° East) are analysed for dependence on Brewer internal temperature and some meteorological parameters. Non-parametric correlation analysis reveals the independence of total ozone from the internal Brewer temperature. Attention is focused on a peculiar case to show, by means of vertical wind velocity profile, the possible effects of lower stratospheric vertical advection on ozone fluctuations.

Total Ozone and UV-B Behavior in 1992–1993 at A Mid-Latitude Station

Daily total ozone data derived by means of a Brewer spectrophotometer at Rome (Italy) during the European Arctic Stratospheric Ozone Experiment (EASOE) were subjected to time series analyses to investigate any possible variations.