Caracterização do transporte de aerossóis de poeira saariana sobre Natal-RN através da técnica de despolarização LIDAR

• Ano de defesa: 2019
• Autor(a) principal: Guedes, Anderson Guimarães
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIAS CLIMÁTICAS
• Palavras-chave em Português: Despolarização LIDAR; Aerossóis atmosféricos; Poeira do Saara; Transporte de poeira; Aerossol de queima de biomassa; Mistura de aerossóis; Aerossol marinho; CNPQ::CIENCIAS EXATAS E DA TERRA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/27386

Saharan dust transport can reach distances of up to 5000 km and it is estimated that around 40 million tons of dust are transported annually from the Sahara to the Amazon basin, having important role as its main source of nutrients. In 2016, the first Brazilian LIDAR system with depolarization channels, DUSTER, designed for atmospheric transport studies and characterization of aerosols on the South Atlantic was installed. The DUSTER system has 4 detection channels, 1064 nm, 355 nm and depolarization channels 532 s nm and 532 p nm. The research was conducted to calibrate the DUSTER system, applying the Δ90∘ method and characterize the atmospheric aerosols that are being transported over the atmospheric Natal city region. The data acquisition took place during the scientific campaigns that were designated MOLOTOV ZERO (February / 2016 to July / 2016), MOLOTOV I (December / 2016 to February / 2017) and MOLOTOV II (November / 2017 to February / 2018). The data obtained by the DUSTER allowed to calculate the ratio of linear depolarization of particles ( ), fundamental parameter in the characterization of atmospheric aerosols. The minimum and maximum values of during the MOLOTOV ZERO, MOLOTOV I and MOLOTOV II campaigns were 0, 02±0, 003 and 0, 29±0, 023, 0, 02±0, 002 and 0, 28±0, 006, 0, 02±0, 001 and 0, 22±0, 001, respectively. There were only 2 events detected compatible with Saharan dust aerosol. The classification of the aerosol intrusions on the atmospheric region of Natal, indicated that they are constituted predominantly by marine aerosols. In some episodes it was possible to detect mixtures of marine aerosol + dust aerosol, however, mixtures between marine aerosol and biomass burning aerosol were predominant. Data from the CIMEL photometer, installed next to DUSTER, corroborate the analyzes and indicate that there is a higher concentration of marine aerosols and of Saharan dust in two campaigns (MOLOTOV ZERO and MOLOTOV II). Analyzes of the HYSPLIT transport model satisfactorily explain the presence of biomass-burning aerosols in the atmosphere locally indicating that their origin is the west coast of the African continent in latitudes to the south, whereas the transportation of Saharan dust aerosols are connected to the central African region. The research data were also correlated with those of the CALIPSO satellite and CATS system (coupled to the International Space Station), indicating the presence of compatible aresols, in some cases, with those detected with DUSTER in soil.