Phosphor Speziation in Mineral Staub und Marineaerosol Partikeln
Zusammenfassung der Projektergebnisse
In order to enhance our understanding of phosphorus availability in the North and Southeastern Tropical Atlantic (NETA/SETA) oceanic regions, we conducted long-term measurements of aerosol particles at two sites: CVAO in Cabo Verde and NDAO in Namibia. In collaboration with local partner institutions (INMG, Cabo Verde and Gobabab, Namibia) atmospheric phosphorus concentrations in both sizeresolved and bulk aerosol particles were quantified. Using highly sensitive LWCC techniques, various forms of phosphorus, including total, inorganic, organic, and soluble phosphorus were measured with the aim of determining the seasonal and interannual phosphorus fluxes in these regions and identifying potential sources and source regions of phosphorus. The results showed significant variability in total phosphorus concentrations between the two sites. On average, phosphorus concentrations at NDAO were 50% higher than those at CVAO, indicating greater phosphorus deposition in the SETA region compared to the NETA regions. Strong seasonal trends influenced by meteorological conditions and air mass influences were observed. While higher concentrations were observed during winter months in the NETA, peak concentrations at NDAO were observed during summer months. Notably, phosphorus was predominantly found in the coarse mode aerosol fractions, with fine-to-coarse mode ratios (PM1.2/PM10) ranging from 0.42 to 0.57 at the NDAO and 0.17 to 0.32 at the CVAO. Inorganic phosphorus contributed over 70% of the total phosphorus at both sites, while organic phosphorus concentrations remained low. Soluble phosphorus fractions were on average about 20% higher at NDAO compared to CVAO and were more prevalent in samples with higher aerosol acidity and organic matter content. During nonmineral dust episodes, a higher soluble phosphorus fraction was observed, suggesting lower solubility of mineral dust-related phosphorus compared to other sources. A strong correlation between phosphorus solubility and particle acidity was found, suggesting that atmospheric processing of aerosol acidic species and particles played a crucial role in enhancing phosphorus solubility in the regions. Multiple sources contributed to atmospheric phosphorus in these regions, with phosphorus abundance in the NETA primarily dominated by Saharan dust events, while Namib desert dust and coastal emissions from sand dunes and biomass burning accounted for the abundance in the SETA region. Correlation analysis indicated that apatite minerals were among the main sources of total phosphorus in dust particles. Our analysis of phosphorus deposition fluxes revealed strong temporal variations and seasonal trends with higher fluxes observed in the SETA region compared to the NETA region. The deposition fluxes of nitrogen and phosphorus indicated a higher phosphorus limitation in the NETA region than in the SETA region, as evidenced by higher deviations from the Redfield ratio observed at CVAO (N:P > 200) compared to NDAO (N:P > 30). These findings have significant implications for combined oceanatmosphere models and our understanding of the key factors influencing the fate of atmospheric phosphorus in the oceans. Moreover, they provide valuable insights into the role of phosphorus in the health of marine and terrestrial ecosystems.
Projektbezogene Publikationen (Auswahl)
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Assessment of trace metal levels in size-resolved particulate matter in the area of Leipzig. Atmospheric Environment, 176, 60-70.
Fomba, Khanneh Wadinga; van Pinxteren, Dominik; Müller, Konrad; Spindler, Gerald & Herrmann, Hartmut
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Seasonal radiogenic isotopic variability of the African dust outflow to the tropical Atlantic Ocean and across to the Caribbean. Earth and Planetary Science Letters, 487, 94-105.
Kumar, Ashwini; Abouchami, W.; Galer, S.J.G.; Singh, Satinder Pal; Fomba, K.W.; Prospero, J.M. & Andreae, M.O.
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Application of TXRF in monitoring trace metals in particulate matter and cloud water. Atmospheric Measurement Techniques, 13(9), 4773-4790.
Fomba, Khanneh Wadinga; Deabji, Nabil; Barcha, Sayf El Islam; Ouchen, Ibrahim; Elbaramoussi, El Mehdi; El, Moursli Rajaa Cherkaoui; Harnafi, Mimoun; El Hajjaji, Souad; Mellouki, Abdelwahid & Herrmann, Hartmut
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Characterization of aerosol particles at Cabo Verde close to sea level and at the cloud level – Part 1: Particle number size distribution, cloud condensation nuclei and their origins. Atmospheric Chemistry and Physics, 20(3), 1431-1449.
Gong, Xianda; Wex, Heike; Voigtländer, Jens; Fomba, Khanneh Wadinga; Weinhold, Kay; van Pinxteren, Manuela; Henning, Silvia; Müller, Thomas; Herrmann, Hartmut & Stratmann, Frank
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First insights into northern Africa high-altitude background aerosol chemical composition and source influences. Atmospheric Chemistry and Physics, 21(24), 18147-18174.
Deabji, Nabil; Fomba, Khanneh Wadinga; El Hajjaji, Souad; Mellouki, Abdelwahid; Poulain, Laurent; Zeppenfeld, Sebastian & Herrmann, Hartmut
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PHOSPHORUS SPECIATION IN NAMIB DESERT DUST PARTICLES, Dust2021, Italy
Fomba, K. W. & Herrmann, H.
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A statistic comparison of multi-element analysis of low atmospheric fine particles (PM2.5) using different spectroscopy techniques. Journal of Environmental Sciences, 114, 194-203.
Zhi, Minkang; Zhang, Kai; Zhang, Xi; Herrmann, Hartmut; Gao, Jian; Fomba, Khanneh Wadinga; Tang, Wei; Luo, Yuqian; Li, Huanhuan & Meng, Fan
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Atmospheric deposition of phosphorus and associated nutrient fluxes in the northeastern and southeastern Tropical Atlantic, SOLAS online Seminar Series on Oceanatmosphere exchange of aerosol particles: impact on marine ecosystems; October 2022
Fomba, K. W.
