Sea spray aerosols impact Earth’s radiation balance by directly scattering solar radiation. They also act as cloud condensation nuclei, thereby altering cloud properties including reflectivity, lifetime and extent. The influence of sea spray aerosol on cloud properties is thought to be particularly strong over remote ocean regions devoid of continental particles. Yet the contribution of sea spray aerosol to the population of cloud condensation nuclei in the marine boundary layer remains poorly understood. Here, using a lognormal-mode-fitting procedure, we isolate sea spray aerosols from measurements of particle size and abundance over the Pacific, Southern, Arctic and Atlantic oceans to determine the contribution of sea spray aerosol to the population of cloud condensation nuclei in the marine boundary layer. On a global basis, with the exception of the high southern latitudes, sea spray aerosol makes a contribution of less than 30% to the cloud condensation nuclei population for air that is supersaturated at 0.1 to 1.0%—the supersaturation range typical of marine boundary layer clouds. Instead, the cloud condensation nuclei population between 70° S and 80° N is composed primarily of non-sea-salt sulfate aerosols, due to large-scale meteorological features that result in entrainment of particles from the free troposphere.

海水喷雾气溶胶会直接散射太阳辐射，从而影响地球的辐射平衡。它们还充当云凝结核，从而改变云的性质，包括反射率，寿命和范围。人们认为，在没有大陆颗粒的偏远海洋地区，海浪气溶胶对云的影响特别强烈。然而，对于海洋边界层中的海雾气溶胶对云凝结核种群的贡献仍然知之甚少。在这里，我们使用对数正态模式拟合程序，从测量太平洋，南部，北冰洋和大西洋海洋的粒径和丰度中分离出海雾气溶胶，以确定海雾气溶胶对云雾凝结核种群的贡献。海洋边界层。在全球范围内，除南部高纬度地区外，对于以0.1％至1.0％过饱和的空气而言，海雾气溶胶对云凝结核种群的贡献不到30％，这是海洋边界层云典型的过饱和范围。相反，由于大规模的气象学特征导致从自由对流层夹带颗粒，介于70°S和80°N之间的云凝结核种群主要由非海盐硫酸盐气溶胶组成。