J. Cañada

Influences of the clearness index for the whole spectrum and of the relative optical air mass on UV solar irradiance for two locations in the Mediterranean area, Valencia and Cordoba

Ultraviolet solar irradiance (290-385 nm) was analyzed in Valencia and Cordoba, Spain, during 1996-1997. Its relation to the instantaneous atmospheric clearness index k t , the relative optical mass m r , the time of the year, and the total or global irradiance on a horizontal surface was established. The maximum values of UV irradiance for each optical mass exponentially diminished with the optical mass, thus for Cordoba and Valencia, G uv = 62.23 m -1.34 r and G uv = 52.84 m -1.30 r , respectively. The UV irradiance in Cordoba represented 4.2% of the total irradiance while in Valencia this percentage was 4.9%. In the case of cloudy days (k t < 0.4), these percentages ranged between 5.6% and 6.8% in Valencia and between 5.1% and 5.5% in Cordoba.

A new method to determine Ångström's turbidity coefficient: Its application for Valencia

Abstract Traditionally the Angstrom turbidity coefficient has been derived from either spectral direct solar radiation measurements or broadband direct solar radiation and precipitable water measurements. The new method for calculating the Angstrom turbidity coefficient presented here is based on the ratio of direct solar radiation to global solar radiation on a horizontal surface and on the “C” model of Iqbal. For this method, it is not necessary to know the precipitable water and the ozone content of the atmosphere. The results of the present model are compared against those of a prior study using experimental data measured at Valencia during 1989–1990. Finally, a graphic method to calculate β for any location and standard meteorological conditions is presented.

Methodology for generating daily clearness index index values Kt starting from the monthly average daily value K̄t. Determining the daily sequence using stochastic models

The facility to generate weather data from limited inputs and independently of specific locations would allow simulations of energetic systems to be run at locations for which detailed weather records do not exist. This article presents a methodology to calculate synthetic daily solar radiation values and describes how sequences of daily global radiation can be generated using as input the monthly average radiation. A stochastic model, ARIMA(1,1,1) is presented, as well.

Aerosol optical characteristics from a summer campaign in an urban coastal Mediterranean area

The authors present a preliminary study of some optical properties of atmospheric aerosols over the area of Valencia, Spain, a coastal Mediterranean city. Measurements of spectral direct irradiance in the 300-1100 nm range were taken simultaneously at three sites: rural-continental, rural-coastal, and urban-coastal, all located within a 50 km radius of the city of Valencia. The irradiance measurements were obtained using three Li-cor 1800 spectroradiometers provided with radiance limiting tubes with field of views (FOVs) of 4.7/spl deg/. The measurements were made under clear sky conditions during a field campaign carried out in the summer of 1998. In order to avoid the uncertainties associated with the determination of the water vapor content and the other atmospheric constituents, the analysis of the spectral aerosol optical thickness (AOT) values was limited to the 400-670 mm spectral band. From the values of the spectral AOT, both the Angstrom coefficients and the aerosol size distributions were obtained. The results show the great dependence of the optical aerosol characteristic on the direction of the prevailing winds (maritime or continental) in this area.

Determination of Angstrom's turbidity coefficient at Valencia

From direct radiation measurements performed in Valencia, the Angstroms turbidity coefficient, β, was derived and compared with the models reported for Avignon, Ajaccio and Dhahran. The variation in the monthly average values of β at Valencia is of a similar trend to that of Avignon, Ajaccio and Dhahran. However, Valencia has shown higher values of β than Avignon and Ajaccio in summer due mainly to the effect of the air mass origin, the air temperature and the water vapour content.

Correlation between global ultraviolet (290–385nm) and global irradiation in Valencia and Cordoba (Spain)

This paper analyses hourly data of global ultraviolet (290–385nm) and global irradiation over a horizontal surface. The data was taken in Valencia (39.5°N, 0.341W) and Cordoba (37.51°N, 4°48W), (Spain) during the years 1996–1999. In order to estimate the ultraviolet solar radiation using global solar radiation values over a horizontal surface, the method of Foyo-Moreno et al. (Foyo-Moreno, I., J. Vida and L. Alados-Arboleda. J. Appl. Meteor. 1998, 38, 1020–1026) has been used. The results obtained with this method are satisfactory with a determination ratio r2=0.98, RMSE=9.3%, MBE=0.5% for Valencia and r2=0.99, RMSE=6.2%, MBE=0.3% for Cordoba.

Erythemal Ultraviolet Exposure in Two Groups of Outdoor Workers in Valencia, Spain

UVexposure is considered to be one of the most important risk factors in skin cancers, mainly in outdoor occupational activities. Outdoor workers receive regular and significant solar UV erythemal radiation (UVER). To quantify the UVER exposure of certain groups of workers, dosimeters are used to measure the biologically effective UV radiation received in the course of their daily work. Two groups of outdoor workers, composed of gardeners and lifeguards, were measured for UVER exposure using sensitive spore‐film filter‐type personal dosimeters (Viospor). The study took place in Valencia, Spain, in June and July 2008, and involved one group of four gardeners and another of five beach lifeguards for a period of 4 and 6 days, respectively. The gardeners’ mean UV exposure was 4.13 ± 0.60 SED day−1, where 1 SED is defined as effective 100 J m−2 when weighted with the CIE erythemal response function, whereas the lifeguards received 11.43 ± 2.15 SED day−1. The mean exposure ratio (ER) relative to ambient of gardeners was 0.09 ± 0.01 and for lifeguards was 0.27 ± 0.05. ER is defined as the ratio between the personal dose on a selected anatomical site and the corresponding ambient dose on a horizontal plane during the same exposure period. The lifeguards received the highest UVER exposure, although both groups had measured UVER exposure in excess of occupational guidelines, indicating that protective measures are necessary.

Erythemal Ultraviolet Exposure of Cyclists in Valencia, Spain

UV exposure is considered to be one of the most important risk factors in skin cancers, mainly in outdoor occupational or recreational activities. Outdoor athletes such as cyclists receive regular and significant solar UV erythemal radiation (UVER). The aim of this work was to quantify UVER exposure of amateur cyclists over the course of several days in their training schedules. To quantify UVER exposure of this group, dosimeters (Viospor) were attached at the top of the helmet in the course of their training. The study took place in Valencia, Spain, in June to July 2008 and February to March 2009, and involved a group of five cyclists over a period of 4 days for each period. The mean 2‐day personal UV exposure was 32.24 ± 4.14 SED (standard erythema dose) in summer and 11.30 ± 5.36 SED in the winter period. One SED is defined as an effective radiant exposure of 100 J m−2 when weighted with the International Commission on Illumination (CIE) erythemal response function. The mean exposure ratio (ER) of cyclists was 0.37 ± 0.04 in summer and 0.40 ± 0.11 in winter. The cyclists received the highest UVER exposure in the summer period, but in both training periods UVER exposure was in excess of occupational and recreational guidelines, indicating that protective measures are very necessary.

Solar UV exposure in construction workers in Valencia, Spain

Exposure to ultraviolet radiation (UVR) has long been recognized as the most important environmental risk factor for melanoma and skin cancer. Outdoor workers are among the groups most at risk from exposure to solar UVR in their daily activities. Sensitive spore-film filter-type personal dosimeters (VioSpor) were used to measure the biologically effective UVR received by construction workers in the course of their daily work. The study took place in Valencia, Spain, in July 2010 and involved a group of eight workers for a period of 5 days. The median UV exposure was 6.11 standard erythema dose (SED) per day, with 1 SED defined as effective 100 J/m2 when weighted with the Commission Internationale de L’Eeclairage erythemal response function. These workers were found to receive a median of 13.9% of total daily ambient ultraviolet erythemal radiation (UVER). Comparison with the occupational UVR exposure limit showed that the subjects had received UVER exposure in excess of occupational guidelines, indicating that protective measures against this risk are highly advisable.

Ultraviolet exposure for different outdoor sports in Valencia, Spain.

The purpose of this study is to quantify ultraviolet (UV) exposure of several groups of amateur athletes in their training or recreational schedules.