A Mechanistic Sea Spray Generation Function Based on the Sea State and the Physics of Bubble Bursting
A Mechanistic Sea Spray Generation Function Based on the Sea State and the Physics of Bubble Bursting
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DOI：
10.1029/2022av000750
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发表时间：
2022-12-01
期刊：
影响因子：
8.4
通讯作者：
Paulot, F.
中科院分区：
文献类型：
--
作者：
Deike, L.;Reichl, B. G.;Paulot, F.
在海洋表面破裂的气泡是海洋喷雾气溶胶的一个重要来源，对辐射和云过程的影响。然而，关键的物理控制参数，包括风速，海况和水温的作用存在很大的不确定性。我们提出了一个机械的海喷雾生成功能，是基于物理泡沫破裂。射流和薄膜液滴的数量和平均液滴半径通过从单个气泡破裂实验室和数值实验中得出的比例定律来描述，作为气泡半径和水的物理化学性质（粘度、密度和表面张力，所有温度的函数）的函数，生产时液滴半径为0.1至500 μ m。接下来，我们对破碎波夹带的气泡尺寸分布进行积分。最后，海喷雾生成函数通过考虑夹带气泡的体积通量，由于破碎波的破碎分布（类似于白顶覆盖）的三阶矩约束的字段中获得。这种机械方法通过破碎分布和夹带的空气通量自然地整合了风和波浪的作用，并通过单独的气泡破裂机制对温度敏感。由此产生的海水喷雾生成函数尚未调整或调整，以匹配任何现有的数据集，在海盐排放量和最近观察到的温度依赖性方面。因此，海盐排放的模型和观测之间的显着的一致性，强烈支持机械的方法和由此产生的海喷雾生成功能。
Bubbles bursting at the ocean surface are an important source of ocean-spray aerosol, with implications on radiative and cloud processes. Yet, very large uncertainties exist on the role of key physical controlling parameters, including wind speed, sea state and water temperature. We propose a mechanistic sea spray generation function that is based on the physics of bubble bursting. The number and mean droplet radius of jet and film drops is described by scaling laws derived from individual bubble bursting laboratory and numerical experiments, as a function of the bubble radius and the water physico-chemical properties (viscosity, density and surface tension, all functions of temperature), with drops radii at production from 0.1 to 500 mu m. Next, we integrate over the bubble size distribution entrained by breaking waves. Finally, the sea spray generation function is obtained by considering the volume flux of entrained bubbles due to breaking waves in the field constrained by the third moment of the breaking distribution (akin to the whitecap coverage). This mechanistic approach naturally integrates the role of wind and waves via the breaking distribution and entrained air flux, and a sensitivity to temperature via individual bubble bursting mechanisms. The resulting sea spray generation function has not been tuned or adjusted to match any existing data sets, in terms of magnitude of sea salt emissions and recently observed temperature dependencies. The remarkable coherence between the model and observations of sea salt emissions therefore strongly supports the mechanistic approach and the resulting sea spray generation function.