New particle formation is globally one of the major sources of aerosol particles and cloud condensation nuclei. As primary emissions are a minor contributor to particle concentrations, secondary new particle formation processes are probably key in determining Antarctic aerosol number concentrations. However, our knowledge of new particle formation and its mechanisms in Antarctica is very limited. Here we study summertime open ocean and coastal new particle formation in the Antarctic Peninsula region based on both ship and station measurements. The rates of particle formation relative to sulfuric acid concentrations, as well as the sulfuric acid dimer-to-monomer ratios, were similar to those seen for sulfuric acid–dimethylamine–water nucleation. Numerous sulfuric acid–amine peaks were identified during new particle formation events, providing evidence that alkylamines were the bases that facilitated sulfuric acid nucleation. Most new particle formation events occurred in air masses arriving from the ice-covered Weddell Sea and its marginal ice zone, which are an important source of volatile sulfur and alkylamines. This nucleation mechanism is more efficient than the ion-induced sulfuric acid–ammonia pathway previously observed in Antarctica, and one that can occur rapidly under neutral conditions. This hitherto overlooked pathway to biologically driven aerosol formation should be considered for estimating aerosol and cloud condensation nuclei numbers in ocean–sea ice–aerosols–climate feedback models.

新粒子的形成是全球气溶胶粒子和云凝聚核的主要来源之一。由于一次排放对粒子浓度的影响很小，因此二次新粒子形成过程可能是确定南极气溶胶数量浓度的关键。然而，我们对南极洲新粒子形成及其机制的了解非常有限。在这里，我们基于船舶和站点测量研究了南极半岛地区夏季开放海洋和沿海新粒子的形成。相对于硫酸浓度的颗粒形成速率以及硫酸二聚体与单体的比率与硫酸-二甲胺-水成核所见的相似。在新颗粒形成事件中发现了许多硫酸-胺峰，提供证据表明烷基胺是促进硫酸成核的碱。大多数新的粒子形成事件发生在来自冰层覆盖的威德尔海及其边缘冰区的气团中，这些冰区是挥发性硫和烷基胺的重要来源。这种成核机制比之前在南极洲观察到的离子诱导的硫酸-氨途径更有效，并且可以在中性条件下迅速发生。在估算海洋-海冰-气溶胶-气候反馈模型中的气溶胶和云凝结核数量时，应考虑这种迄今为止被忽视的生物驱动气溶胶形成途径。大多数新的粒子形成事件发生在来自冰层覆盖的威德尔海及其边缘冰区的气团中，这些冰区是挥发性硫和烷基胺的重要来源。这种成核机制比之前在南极洲观察到的离子诱导的硫酸-氨途径更有效，并且可以在中性条件下迅速发生。在估算海洋-海冰-气溶胶-气候反馈模型中的气溶胶和云凝结核数量时，应考虑这种迄今为止被忽视的生物驱动气溶胶形成途径。大多数新的粒子形成事件发生在来自冰层覆盖的威德尔海及其边缘冰区的气团中，这些冰区是挥发性硫和烷基胺的重要来源。这种成核机制比之前在南极洲观察到的离子诱导的硫酸-氨途径更有效，并且可以在中性条件下迅速发生。在估算海洋-海冰-气溶胶-气候反馈模型中的气溶胶和云凝结核数量时，应考虑这种迄今为止被忽视的生物驱动气溶胶形成途径。以及在中性条件下可以迅速发生的一种。在估算海洋-海冰-气溶胶-气候反馈模型中的气溶胶和云凝结核数量时，应考虑这种迄今为止被忽视的生物驱动气溶胶形成途径。以及在中性条件下可以迅速发生的一种。在估算海洋-海冰-气溶胶-气候反馈模型中的气溶胶和云凝结核数量时，应考虑这种迄今为止被忽视的生物驱动气溶胶形成途径。