Analysis of the UVB radiation during the events of influence of the Antarctic Ozone Hole over South of Brazil

• Main Author: Culau Lopes, Bibiana
• Other Authors: Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de la Réunion, Universidade federal de Santa Maria (Brésil), Damaris Kirsch Pinheiro, Hassan Benchérif
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2022
• Subjects: UV radiation; UV index; Antarctic ozone hole; Spectrophotometer Brewer; Rayonnement UV; Indice UV; Trou d'ozone antarctique; Brewer spectrophotomètre; Radiação UV; Índice UV; Buraco de Ozônio na Antártida; Espectrofotômetro Brewer; [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Antarctic; The Antarctic; Antarc*; Antarctique*; Antártida
• Online Access: https://theses.hal.science/tel-03771818; https://theses.hal.science/tel-03771818/document; https://theses.hal.science/tel-03771818/file/2022LARE0009_B_CULAU_LOPEZ.pdf

Excess exposure to solar UV radiation can be harmful to all living beings. It can affect aquatic and land animals, plants and can cause serious issues on human health, such as sunburn, eye damage and long-term exposure can lead to skin cancer, photoaging. Antarctic Ozone hole (AOH) is characterized by an extreme reduction in ozone content in the Antarctic region during spring in the southern hemisphere. Secondary effects of AOH are caused by air masses poor in ozone that reach mid-latitude regions, including the south of Brazil. The low content in ozone in these air masses allows the higher intensity of UV radiation to reach the surface, due to less absorption of radiation by ozone. The simplest way to alert the population on the amount of UV radiation they are being exposed to is through the UV index, depending on its level, precautions can be taken to avoid excessive exposure. Based on that, this study aimed to investigate the behavior of solar UV radiation, through analysis of UV index collected in the South of Brazil (29.4° S, 53.8° O) using ground and satellite UV radiation data. The ground measurements were taken with a Brewer Spectrophotometer and includes UV index, erythema dose, UV-B non-weighted and UV daily integral. UV index from satellite was retrieved from AURA/Ozone Monitoring Instrument. They were compared and the climatology analysis of ground measurements was done for seasonal and interannual variations, in a period from 2005 to 2017 and looking at data in all-sky conditions and separately days of clear sky conditions. Selection of clear sky days was done through observation of gaussian curve of irradiance and with cloud fraction data and images from an All-sky camera placed in the same site of the ground instrument. UV radiation from Brewer presents a very typical behavior of solar UV radiation on the southern hemisphere, showing lower values during winter and the highest values during summer. However, very high (from 9 to 10) and even extreme (above 11) values were measured in the spring and ...