The contribution of natural sources to PM10 is generally unknown, being sea salt one of these sources, which is especially important in coastal countries. The objective of this work is to evaluate the contribution of sea salt to the PM10 concentration values along the Portuguese coast. For that, four air quality monitoring sites distributed along the coast and with PM10 valid data were selected, using the 2018 reference year. Each monitoring site was characterized in terms of the air mass trajectory patterns associated to the PM10 concentrations, using the HYSPLIT model and cluster analysis. The contribution of sea salt was assessed using data simulated by the WRF-CHIMERE modelling system, used for the air quality operational forecast for Portugal and extensively validated each year. The modelling results for each study site were extracted and processed to calculate the contribution of sea salt to the simulated total PM10 values. The results show that most trajectories came from the Atlantic Ocean, and the higher sea salt concentrations were associated to these trajectories. The sea salt contribution ranged from 7 to 15%, being higher at Atlantic-centre site and lower at the southernmost (Atlantic-Mediterranean) station. This sea salt contribution is expected to be higher during spring and lower during autumn.

天然来源对 PM10 的贡献通常是未知的，海盐是这些来源之一，这在沿海国家尤为重要。这项工作的目的是评估海盐对葡萄牙沿海 PM10 浓度值的贡献。为此，使用 2018 年参考年，选择了四个分布在沿海并具有 PM10 有效数据的空气质量监测点。使用 HYSPLIT 模型和聚类分析，根据与 PM10 浓度相关的气团轨迹模式对每个监测站点进行了表征。海盐的贡献是使用 WRF-CHIMERE 建模系统模拟的数据进行评估的，这些数据用于葡萄牙的空气质量业务预测，并且每年都得到广泛验证。提取并处理每个研究地点的建模结果，以计算海盐对模拟总 PM10 值的贡献。结果表明，大多数轨迹来自大西洋，较高的海盐浓度与这些轨迹有关。海盐贡献范围为 7% 至 15%，大西洋中心站点较高，最南端（大西洋-地中海）站点较低。预计这种海盐贡献在春季较高，秋季较低。在大西洋中心站点较高，在最南端（大西洋-地中海）站点较低。预计这种海盐贡献在春季较高，秋季较低。在大西洋中心站点较高，在最南端（大西洋-地中海）站点较低。预计这种海盐贡献在春季较高，秋季较低。