Seasonal variability of aerosol concentration and size distribution in Cape Verde using a continuous aerosol optical spectrometer

[EN] One year of, almost continuous, measurements of aerosol optical properties and chemical composition were performed at the outskirts of Praia, Santiago Island, Cape Verde,within the framework of CV-DUST (Atmospheric aerosol in Cape Verde region: seasonal evaluation of composition, sources and tr...

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Detalles Bibliográficos
Autores: Pio, Casimiro A., Cardoso, João Gomes, Cerqueira, Mário Miguel Azevedo, Calvo Gordaliza, Ana Isabel, Nunes, Teresa Filomena Vieira, Alves, Célia dos Anjos, Jorge, Danilo Custódio, Almeida, Susana Marta, 1975-, Almeida-Silva, Marina, 1988-
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:Universidad de León
Repositorio:BULERIA. Repositorio Institucional de la Universidad de León
OAI Identifier:oai:buleria.unileon.es:10612/25883
Acceso en línea:https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2014.00015
https://hdl.handle.net/10612/25883
Access Level:acceso abierto
Palabra clave:Física
Meteorología
Sahara dust
Cape Verde
PM level
Size distribution
Seasonal variation
2509.02 Contaminación Atmosférica
2501.05 Química Atmosférica
2501.16 Difusión (Atmosférica)
Descripción
Sumario:[EN] One year of, almost continuous, measurements of aerosol optical properties and chemical composition were performed at the outskirts of Praia, Santiago Island, Cape Verde,within the framework of CV-DUST (Atmospheric aerosol in Cape Verde region: seasonal evaluation of composition, sources and transport) research project, during 2011. This articlereports the aerosol number and mass concentration measurements using a GRIMM Optical Aerosol Spectrometer that provides number size discrimination into 31 size ranges from 0.25to32μm. Time series of 5 min average PM10 concentrations revealed peakvalues higher than 1000μg.m−3during winter dust storm events originating over NorthernAfrica. The 24 h average concentrations exceeded the World Health Organization (WHO) guidelines for PM2.5and PM10in 20 and 30% of the 2001 days, respectively. Annual average mass concentrations (±standard deviation) for PM1,PM2.5,and PM10 were 5±5,19±21, and 48±64μg.m−3, respectively. The annual PM2.5and PM10values were also above the limits prescribed by the WHO (10 and 20μg.m−3, respectively). The aerosolmass size distribution revealed two main modes for particles smaller than 10μm: a fine mode (0.7–0.8μm), which possibly results of gas to particle conversion processes; and a coarse mode with maxima at 3–4μm, which is associated with desert dust and sea saltsources. Within the coarse mode two sub-modes with maxima at 5–6 and 10–12μm were frequently present