Sea spray aerosol (SSA) formation have a major role in the climate system, but measurements at a global-scale of this micro-scale process are highly challenging. We measured high-resolution temporal patterns of SSA number concentration over the Atlantic Ocean, Caribbean Sea, and the Pacific Ocean covering over 42,000 km. We discovered a ubiquitous 24-hour rhythm to the SSA number concentration, with concentrations increasing after sunrise, remaining higher during the day, and returning to predawn values after sunset. The presence of dominating continental aerosol transport can mask the SSA cycle. We did not find significant links between the diel cycle of SSA number concentration and diel variations of surface winds, atmospheric physical properties, radiation, pollution, nor oceanic physical properties. However, the daily mean sea surface temperature positively correlated with the magnitude of the day-to-nighttime increase in SSA concentration. Parallel diel patterns in particle sizes were also detected in near-surface waters attributed to variations in the size of particles smaller than ~1 µm. These variations may point to microbial day-to-night modulation of bubble-bursting dynamics as a possible cause of the SSA cycle.

海喷雾气溶胶 (SSA) 的形成在气候系统中起着重要作用，但在全球范围内对这种微尺度过程进行测量极具挑战性。我们测量了大西洋、加勒比海和太平洋上超过 42,000 公里的 SSA 数浓度的高分辨率时间模式。我们发现 SSA 数浓度的 24 小时节律无处不在，日出后浓度增加，白天保持较高，日落后恢复到黎明前的值。占主导地位的大陆气溶胶运输的存在可以掩盖 SSA 循环。我们没有发现 SSA 数浓度的昼夜循环与地表风、大气物理特性、辐射、污染和海洋物理特性的昼夜变化之间存在显着联系。然而，日平均海面温度与 SSA 浓度从白天到夜间增加的幅度呈正相关。在近地表水中也检测到平行的粒径模式，这归因于小于 ~1 µm 的颗粒尺寸的变化。这些变化可能表明微生物对气泡破裂动力学的昼夜调节可能是 SSA 循环的原因。