Aerosol Observing System (AOS): cloud condensation nuclei data - aosccn

The cloud condensation nuclei counter measures the concentration of aerosol particles by drawing an air sample through a column with thermodynamically unstable supersaturated water vapor that can condense onto aerosol particles. Particles that are activated, i.e., grown larger in the process, are counted and sized by an optical particle counter (OPC). In this way the CCN measures activated ambient aerosol particle number concentration as a function of supersaturation. \n \nARM operates both one- and two-column versions of the CCN.

云凝结核计数器（cloud condensation nuclei counter）通过使空气样品流经装有热力学不稳定过饱和水蒸气的柱体，来测定气溶胶粒子浓度；该水蒸气可在气溶胶粒子表面发生凝结。在此过程中被活化（即粒径增大）的粒子将由光学粒子计数器（optical particle counter, OPC）完成计数与粒径测定。通过该方式，云凝结核计数器（CCN）可测定活化的环境气溶胶粒子数浓度随过饱和度的变化关系。

ARM同时部署了单柱型与双柱型的云凝结核计数器。