Rapid modification of cloud‐nucleating ability of aerosols by biogenic emissions
Rapid modification of cloud‐nucleating ability of aerosols by biogenic emissions
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DOI：
10.1002/2013gl057895
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发表时间：
2013-12
影响因子：
5.2
通讯作者：
Yan Ma;S. Brooks;G. Vidaurre;A. Khalizov;Lin Wang;Renyi Zhang
中科院分区：
文献类型：
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作者：
Yan Ma;S. Brooks;G. Vidaurre;A. Khalizov;Lin Wang;Renyi Zhang
虽然二次有机气溶胶的形成已经得到了很好的研究，但生物源性挥发性有机化合物的氧化产物在多大程度上凝结在初级气溶胶上并改变其云核性质仍然高度不确定。研究表明，在α -蒎烯浓度为7 - 37 ppbv、臭氧浓度为20 ppbv的条件下，由α -蒎烯和臭氧反应产生的水溶性有机酸在30 - 60分钟内迅速积累到预先存在的颗粒上，形成有机材料的涂层，质量分数达到80-90%。云凝结核（CCN）测量表明，最初疏水的气溶胶在过饱和0.22%时迅速转化为有效的CCN。我们的研究结果表明，大气气溶胶种群中相当一部分的活化电位的变化是由老化过程中形成的涂层的形成和组成控制的，而不是由原始粒径或组成控制的。
Although secondary organic aerosol formation is well studied, the extent to which oxidation products of biogenic volatile organic compounds condense onto primary aerosols and modify their cloud‐nucleating properties remains highly uncertain. Here we show that water‐soluble organic acids produced from the reaction between α‐pinene and ozone rapidly accumulate onto preexisting particles forming coatings of organic materials that reach a mass fraction of 80–90% within a time period of 30 to 60 min for the reactant conditions of 7 to 37 ppbv α‐pinene and 20 ppbv ozone. Cloud condensation nuclei (CCN) measurements reveal that the initially hydrophobic aerosols are rapidly converted to efficient CCN at a supersaturation of 0.22%. Our results imply that changes in the activation potential of a significant fraction of the atmospheric aerosol population are controlled by the formation and composition of coatings formed during the aging process, rather than by the original particle size or composition.