6533b7dcfe1ef96bd1272a2f

RESEARCH PRODUCT

Ultraviolet radiation protection by a beach umbrella.

José A. Martínez-lozanoManuel NuñezMaría P. Utrillas

subject

business.industryScatteringUltraviolet RaysIrradianceGeneral MedicineRadiusRadiationBiochemistryBathing BeachesDiffuse irradianceOpticsRadiation ProtectionProtective ClothingVertical directionEnvironmental scienceHumansScattering RadiationPhysical and Theoretical ChemistrybusinessUltraviolet radiationStreet canyon

description

A beach umbrella intercepts all direct UV irradiance, but only part of the diffuse component. Using a simple sky view factor model, we have determined the fraction of the hemispheric diffuse irradiance that is not intercepted by the umbrella. Assuming a sensor at the surface and close to the center of the umbrella, isotropic diffuse irradiance and for an umbrella of 80 cm radius and 100 cm high, our results show that approximately 34% of the incident horizontal irradiance is not intercepted by the umbrella. These results agree with irradiance measurements conducted with and without the umbrella. The model is next extended to examine receipt of UV radiation by a human figure in a vertical position, either standing or sitting.

10.1111/j.1751-1097.2009.00677.xhttps://pubmed.ncbi.nlm.nih.gov/20059729