A Study of UVER in Santiago, Chile Based on Long-Term In Situ Measurements (Five Years) and Empirical Modelling

Abstract

Ultraviolet radiation is a highly energetic component of the solar spectrum that needs to be monitored because is harmful to life on Earth, especially in areas where the ozone layer has been depleted, like Chile. This work is the first to address the long-term (five-year) behaviour of ultraviolet erythemal radiation (UVER) in Santiago, Chile (33.5° S, 70.7° W, 500 m) using in situ measurements and empirical modelling. Observations indicate that to alert the people on the risks of UVER overexposure, it is necessary to use, in addition to the currently available UV index (UVI), three more erythema indices: standard erythemal doses (SEDs), minimum erythemal doses (MEDs), and sun exposure time (tery). The combination of UVI, SEDs, MEDs, and tery shows that in Santiago, individuals with skin types III and IV are exposed to harmfully high UVER doses for 46% of the time that UVI indicates is safe. Empirical models predicted hourly and daily values UVER in Santiago with great accuracy and can be applied to other Chilean urban areas with similar climate. This research inspires future advances in reconstructing large datasets to analyse the UVER in Central Chile, its trends, and its changes.

Observational Investigation of the Low‐Level Jets in the Metropolitan Region of São Paulo, Brazil

“…This dispersion diagram (not show here) showed that hourly values of $${T}_{78.6}$$ and $${T}_{1.5}$$ have a linear distribution with a Pearson's coefficient of 0.99. Similar procedure has been used for developing empirical expressions to diagnosticate hourly values of diffuse and other components of solar radiation at the surface (Furlan et al., 2012; González‐Rodríguez et al., 2021).…”

“…The extrapolation is based on an empirical expression 𝐴𝐴 𝐴𝐴urban = 𝐴𝐴1.5 = 1.868 + 1.004 * 𝐴𝐴78.6 , obtained by fitting a first order polynomial through the dispersion diagram of the temperature measured in the surface at 1.5 m agl ( have a linear distribution with a Pearson's coefficient of 0.99. Similar procedure has been used for developing empirical expressions to diagnosticate hourly values of diffuse and other components of solar radiation at the surface (Furlan et al, 2012;González-Rodríguez et al, 2021).…”

Actualization of Semi-Empirical Equation for UV Index

“…-by employing parametrical models which are derived from spectral codes [6 -9], -using statistical models, such as polynomial regression analysis [10] or by using other types of models developed by statistical analysis of time series [11],…”

“…Some authors analyse how damage from sun exposure depends on cumulative daily doses and not only on UVI [10,34] and how exposure in the middle of the day to low levels of UV (UVI=2) poses a significant risk of erythema for people with lighter skin phototypes, even for a duration of 3 h [35].…”

Ultraviolet Erythemal Irradiance (UVER) under Different Sky Conditions in Burgos, Spain: Multilinear Regression and Artificial Neural Network Models

“…Ultraviolet radiation (UV) represents a small fraction of total solar radiation (5-7%) [1]. It is a highly energetic component of the solar spectrum that must be monitored as it can be detrimental to life on Earth [2], becoming the main risk factor for human health among photo-biological factors [3]. The UV region of the solar spectrum spans wavelengths between 100 and 400 nm, and it is divided into three components, i.e., UVA, UVB, and UVC.…”