PHOsphorus Speciation in mineral Dust and Marine Aerosol Particles

像磷这样的大量营养素是维持海洋食物链和生物的浮游植物等海洋微生物生长所必需的。另一方面，浮游植物向大气释放与气候有关的有机化合物，例如DMS，这些化合物可以被氧化成硫酸，这可能随后导致形成新的颗粒，可以作为云凝结核。因此，关于这些微生物的磷可利用性的信息对于理解海洋-大气相互作用非常重要。大气沉降是开放海洋磷的主要来源；但是，仍然需要关于大气磷浓度通量、生物利用度和来源的信息，这些信息对于了解它们在海洋中的命运，特别是在热带北大西洋和东南大西洋区域的命运是必要的。为数不多的可用数据主要是短期巡航测量数据，在应用于理解季节周期和长期预测方面受到限制。为了提高我们对这些海洋地区控制磷有效性和生物有效性的来源和因素的认识，应进行尺寸分辨和散装气溶胶颗粒的大气磷的长期测量。此外，将开发和优化分析方法（基于三种技术的结合），以提高检测灵敏度，以确定可溶性磷和总磷的细模式颗粒，因为在这种粒度分数中经常遇到低负荷。获得的数据应使用用于调查这些地区磷的主要来源，如矿物粉尘、生物质燃烧等来源的作用；人为燃烧气溶胶；这些地区磷的形态（有机和无机组成）、溶解度、生物利用度、大气处理和季节变化。此外，为了更好地描述这些地区的气溶胶输送和沉积，需要采用区域沙尘模式模拟。所得结果将有助于建立海洋-大气联合模式，并有助于了解控制海洋中大气磷命运的关键因素。

Macro-nutrients such as phosphorous are required for the growth of oceanic microorganisms such as phytoplankton that sustain the oceans food chain and biology. On the other hand, phytoplankton species emit climate-relevant organic compounds, e.g, DMS to the atmosphere that can be oxidized to sulphuric acid, which may subsequently lead to the formation of new particles that can act as cloud condensation nuclei. Information about phosphorus availability to these microorganisms is, thus, very important for the understanding of the ocean-atmosphere interactions. Atmospheric deposition is the main source of phosphorus to the open ocean; however, information about atmospheric phosphorus concentration fluxes, bioavailability and sources which is necessary to understand their fate in the oceans especially in the regions of the tropical North and South-eastern Atlantic is still needed. The few available data are mainly short-term cruise measurements which are limited in their application to the understanding of seasonal cycles and long-term predictions. To improve our knowledge on the sources and factors controlling phosphorus availability and bioavailability in these oceanic regions, long-term measurements of atmospheric phosphorus in both size-resolved and bulk aerosol particles shall be performed. Furthermore, analytical methods will be developed and optimized (based on the combination of three techniques) to enhance the detection sensitivity for the determination of soluble and total phosphorus in fine mode particles due to the low loadings often encountered in this particle size fraction. The acquired data shall be used to investigate the main sources of phosphorus in these regions, the role of sources such as mineral dust, biomass burning; anthropogenic combustion aerosols on the; speciation (organic and inorganic composition), solubility, bioavailability, atmospheric processing, and the seasonal variation of phosphorus in these regions. In addition, a regional dust model simulation shall be applied to better describe the aerosol transport and deposition in these regions. The obtained results will be useful for combined ocean-atmosphere models and the understanding of the key factors controlling the fate of atmospheric phosphorus in the oceans.