Attenuation of UV-C Solar Radiation as a Function of Altitude (0 ≤ z ≤ 100 km): Rayleigh Diffusion and Photo Dissociation of O<sub>2</sub>Influence

• 作者: Carlos Ríos-Martínez David Jacobo Navarro-Solís Eduardo Manzanares-Acu?a Fernando Mireles-García J. Ignacio Dávila-Rangel José Luis Pinedo-Vega Sonia Azucena Saucedo-Anaya Valentín Badillo-Almaraz
• 来源期刊: 大气和气候科学(英文)
• 学科: 医学
• 关键词: UV-C Radiation RAYLEIGH Scattering O2 PHOTODISSOCIATION
• 年，卷（期）: dqhqhkxyw_2017,（4）
• 页码范围: 540-553
• 页数: 14页
• 分类号: R73

摘要

In this paper, we present an analysis of attenuation for UV-C radiation () as a function of the altitude z () by calculating the interaction ratio between the UV-C radiation and the molecular species susceptible of interact with UV-C radiation. The Rayleigh scattering spectral cross sections were calculated, the UV-C spectral cross sections of the species susceptible of interact with UV-C radiation and the UV extraterrestrial (ETR) solar spectrum were standardized with wavelength steps of 1 nm, and The International Standard Atmosphere model (ISO 1972) was adapted to calculate the molecular density. These data were utilized to calculate the photodissociation and Rayleigh scattering ratios as a function of the altitude and to determine to what measure the photodissociation and the Rayleigh diffusion were determinants of the attenuation of UV-C radiation. It became clear that the photo dissociation of O2 is the primordial mechanism of attenuation for the UV-C radiation, but the Rayleigh diffusion appears like a mechanism that encreases the photon flux, raising the performance of the O2 photodissociation. The attenuation capacities of N2O, CO2 and water vapor (H2O) over the UV-C radiation are all similar, although smaller (less than 0.6%), and this is due to their low concentration. The O3, has the theoretical greater attenuation capacity, but it is found in mid-range altitudes? (), where the residual UV-C photons has almost vanished by O2 photo dissociation or Rayleigh diffusion, so the real effect over the UV-C attenuation is minimum.