Analise da radiação UV-B durante os eventos de influência do buraco de ozônio antártico na região sul do Brasil

• Autor(a) principal: Lopes, Bibiana Culau
• Data de Publicação: 2022
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• Texto Completo: http://repositorio.ufsm.br/handle/1/25983
• topic: Radiação UV; Índice UV; Buraco de Ozônio na Antártida; Espectrofotômetro Brewer; UV radiation; UV index; Antarctic ozone hole; Brewer spectrophotometer; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::METEOROLOGIA

Exposure to the sun is fundamental for human health and the growth and development of f lora and fauna, although excessive exposure to the sun’s UV rays can be harmful to all living things. It can affect aquatic and terrestrial animals, plants and can cause serious problems on human health, such as burns, eye damage and long-term exposure can lead to skin cancer and accelerate skin aging. Ozone is the main gas in the Earth’s atmosphere that absorbs UV radiation in the stratosphere. The Antarctic Ozone Hole (AOH) is characterized by an extreme reduction in ozone levels in the Antarctic region in the spring. The secondary effects of the AOH are caused by the displacement of ozone-poor air masses from the polar vortex to the mid-latitudes, including southern Brazil. On this basis, this study aimed to investigate the behavior of solar UV radiation, through the analysis of the UV index collected in southern Brazil (29,4◦ S, 53,8◦ O) using ground (Brewer spectrophotometer) and satellite UV radiation data. The ground-based measurements include UV index, erythemal dose, unweighted UV-B, and daily UV integral. The UV data used covers the period 2005-2017 were compared with observations from the Ozone Monitoring Instrument (OMI) experiment onboard the Aura satellite. Overall, UV radiation in southern Brazil, in Santa Maria, is dominated by the annual seasonal cycle, with a maximum in summer and a minimum in winter. However, very high and even extreme UV indices were measured in spring and fall. Spectral analysis by the wavelet method showed that the variability of UVradiation in southern Brazil is also modulated by 3 forcing: El-Nino Southern Oscillation (ENSO), the Quasi-Biennial Oscillation (QBO) and the solar cycle. As for the influence of anomalies due to the secondary effect of the AOH, we obtained an average reduction of 1% of the total ozone column, with an average increase of 4% of the UV index, under clear-sky condition.