Assessment of cloud supersaturation by size-resolved aerosol particle and cloud condensation nuclei (CCN) measurements
Assessment of cloud supersaturation by size-resolved aerosol particle and cloud condensation nuclei (CCN) measurements
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DOI：
10.5194/amt-7-2615-2014
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发表时间：
2014-08
影响因子：
3.8
通讯作者：
M. Krüger;S. Mertes;T. Klimach;Yafang Cheng;H. Su;J. Schneider;M. Andreae;U. Pöschl;D. Rose
中科院分区：
文献类型：
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作者：
M. Krüger;S. Mertes;T. Klimach;Yafang Cheng;H. Su;J. Schneider;M. Andreae;U. Pöschl;D. Rose
抽象。在这项研究中，我们展示了如何尺寸分辨的测量气溶胶粒子和云凝结核（CCN）可以用来表征云中水汽的过饱和度。该方法是在ACRIDICON-Zugspitze活动期间（2012年9月17日至10月4日）在高阿尔卑斯山研究站Schneefernerhaus（德国阿尔卑斯山，海拔2650米）开发和应用的。总的和间隙气溶胶粒子的数量尺寸分布测量与扫描迁移率粒度分析仪（SMPS），和尺寸分辨的CCN效率谱记录与CCN计数器系统在不同的过饱和度水平。在云的演变过程中，气溶胶粒子暴露于不同的过饱和水平。我们概述和比较不同的估计的下限和上限（慢，高）和平均值（Savg）的峰值过饱和遇到的粒子在云中。从尺寸分辨的CCN效率谱导出Slow和Savg的主要优点是，它不需要关于气溶胶吸湿性的特定知识或假设，而这些知识或假设是从气溶胶尺寸分布数据导出Slow、Shigh和Savg的估计所需的。对于所调查的云事件，我们得出Slow a 0.07- 0.25%，Shigh a 0.86-1.31%和Savg a 0.42- 0.68%。
Abstract. In this study we show how size-resolved measurements of aerosol particles and cloud condensation nuclei (CCN) can be used to characterize the supersaturation of water vapor in a cloud. The method was developed and applied during the ACRIDICON-Zugspitze campaign (17 September to 4 October 2012) at the high-Alpine research station Schneefernerhaus (German Alps, 2650 m a.s.l.). Number size distributions of total and interstitial aerosol particles were measured with a scanning mobility particle sizer (SMPS), and size-resolved CCN efficiency spectra were recorded with a CCN counter system operated at different supersaturation levels. During the evolution of a cloud, aerosol particles are exposed to different supersaturation levels. We outline and compare different estimates for the lower and upper bounds (Slow, Shigh) and the average value (Savg) of peak supersaturation encountered by the particles in the cloud. A major advantage of the derivation of Slow and Savg from size-resolved CCN efficiency spectra is that it does not require the specific knowledge or assumptions about aerosol hygroscopicity that are needed to derive estimates of Slow, Shigh, and Savg from aerosol size distribution data. For the investigated cloud event, we derived Slow a 0.07–0.25%, Shigh a 0.86–1.31% and Savg a 0.42–0.68%.