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Publication
As intrusões de poeiras do Norte de África em Portugal Continental de março de 2022
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Authors
Advisor(s)
Abstract(s)
A presente dissertação teve como objetivo principal o estudo do evento de intrusão de
poeiras ocorrido em março de 2022 em Portugal continental, com especial atenção à
sua duração e intensidade. A pesquisa baseou-se na análise de dados de medições de
concentração de partículas em suspensão, especificamente PM10 e PM2.5, além de
variáveis atmosféricas que permitiram compreender o contexto que favoreceu o
transporte das poeiras provenientes do norte de África até ao território português.
O caráter excecional deste episódio ficou evidenciado pelos valores recorde de
concentração dos poluentes estudados, em comparação com os últimos dez anos
(2012-2021). Os níveis extremamente elevados de má qualidade do ar registados, com
concentrações médias diárias de PM10 a ultrapassarem os 570 µg/m³ na estação de
Fornelo do Monte, sugerem que este evento poderá ter tido um impacto muito negativo
na saúde humana, tendo sido ultrapassado o valor máximo registado anterior a março
de 2022 de 500 µg/m³ na estação da Ervedeira. Contrariamente à sua intensidade, as
intrusões de março de 2022 em Portugal continental não se distinguiram pela sua
duração, que foi consideravelmente inferior a outros eventos significativos da última
década.
Os dias mais críticos do evento ocorreram nos dias 15 e 16, quando os valores diários
e horários mais elevados foram registados nas estações de Fornelo do Monte e Fundão,
na Chamusca, Fernando Pó e em Terena.
Este período de má qualidade do ar em Portugal continental teve origem numa situação
sinótica dominada pela atividade de uma depressão de bloqueio centrada no norte de
Marrocos, cuja circulação facilitou o transporte das poeiras ao longo do seu bordo
oriental. Uma corrente rápida de vento de sul e sudeste, com velocidades que
ultrapassaram os 100 km/h entre os 1500 e os 3000 metros de altitude, assegurou a
formação de uma extensa pluma na troposfera inferior.
The main objective of this dissertation was to study the dust intrusion event that occurred in March 2022 in mainland Portugal, with special attention to its duration and intensity. The research was based on the analysis of data from measurements of the concentration of suspended particles, specifically PM10 and PM2.5, in addition to atmospheric variables that allowed us to understand the context that favored the transport of dust from North Africa to Portuguese territory. The exceptional nature of this episode was highlighted by the record concentration values of the pollutants studied, compared to the last ten years (2012-2021). The extremely high levels of poor air quality recorded, with average daily PM10 concentrations exceeding 570 µg/m³ at Fornelo do Monte station, suggest that this event may have had a very negative impact on human health, with the maximum value being exceeded recorded prior to March 2022 of 500 µg/m³ at the Ervedeira station. Contrary to their intensity, the March 2022 intrusions in mainland Portugal were not distinguished by their duration, which was considerably shorter than other significant events in the last decade. The most critical days of the event occurred on the 15th and 16th, when the highest daily and hourly values were recorded at the Fornelo do Monte and Fundão stations, in Chamusca, Fernando Pó and in Terena. This period of poor air quality in mainland Portugal originated from a synoptic situation dominated by the activity of a blocking depression centered in northern Morocco, whose circulation facilitated the transport of dust along its eastern edge. A fast wind current from the south and southeast, with speeds exceeding 100 km/h between 1500 and 3000 meters in altitude, ensured the formation of an extensive plume in the lower troposphere.
The main objective of this dissertation was to study the dust intrusion event that occurred in March 2022 in mainland Portugal, with special attention to its duration and intensity. The research was based on the analysis of data from measurements of the concentration of suspended particles, specifically PM10 and PM2.5, in addition to atmospheric variables that allowed us to understand the context that favored the transport of dust from North Africa to Portuguese territory. The exceptional nature of this episode was highlighted by the record concentration values of the pollutants studied, compared to the last ten years (2012-2021). The extremely high levels of poor air quality recorded, with average daily PM10 concentrations exceeding 570 µg/m³ at Fornelo do Monte station, suggest that this event may have had a very negative impact on human health, with the maximum value being exceeded recorded prior to March 2022 of 500 µg/m³ at the Ervedeira station. Contrary to their intensity, the March 2022 intrusions in mainland Portugal were not distinguished by their duration, which was considerably shorter than other significant events in the last decade. The most critical days of the event occurred on the 15th and 16th, when the highest daily and hourly values were recorded at the Fornelo do Monte and Fundão stations, in Chamusca, Fernando Pó and in Terena. This period of poor air quality in mainland Portugal originated from a synoptic situation dominated by the activity of a blocking depression centered in northern Morocco, whose circulation facilitated the transport of dust along its eastern edge. A fast wind current from the south and southeast, with speeds exceeding 100 km/h between 1500 and 3000 meters in altitude, ensured the formation of an extensive plume in the lower troposphere.
Description
Keywords
Intrusão de poeira Intensidade Duração Depressão de bloqueio