Studies on physical-chemical processes of aerosol-cloud interaction

云凝结核(CCN)的活性由气溶胶直径、水溶性组分分数和表面张力决定。我们将CCN活性量化为这些参数的函数，并将其与云形成过程联系起来。a)城市空气中气溶胶CCN活性的控制因素我们使用气溶胶质谱仪、黑碳(BC)仪器和CCN计数器测量了东京气溶胶的化学成分、混合状态和CCN活性。我们发现厚涂层BC的CCN活性是由水溶性化合物的化学组成控制的。薄涂层BC的CCN活性受涂层厚度的控制。B)气溶胶-云相互作用的测量我们在春季对位于日本附近1-2公里处的云内外的气溶胶和云粒进行了飞机测量。我们发现，厚涂层的BC粒子被有效地带进了云中，这与地面测量结果一致。这也是S…进一步证明了BC可以作为定量研究气溶胶-云相互作用的良好示踪剂。c)CCN形成的时间常数我们从韩国济州岛获得的数据表明，几天内从亚洲大陆输送的气溶胶的CCN活性主要受水溶性组分的控制。据估计，有机气溶胶表面张力的降低也有助于CCN的活性。在北京附近还测量了不同类型气溶胶的CCN活性。观测到的CCN活动与在东京和济州岛获得的理解是一致的。4)云探测器及其空气动力学特性的校准使用高精度的标准粒子来校准光散射云探测器。我们对安装在飞机上的探测器周围的气流进行了空气动力学计算，发现云滴的收集效率很高。E)利用轨迹模型计算了根据不同CCN浓度预测的云滴的尺寸分布。通过数值实验估算了CCN-云相互作用的灵敏度。较少

Cloud condensation nuclei (CCN) activity is determined by aerosol diameter, fraction of water soluble components, and surface tension. We quantified CCN activities as a function of these parameters and related them with cloud formation processes.A)Controlling factors of CCN activities of aerosol in urban airWe measured chemical composition, mixing states, and CCN activity of aerosol in Tokyo using an aerosol mass spectrometer, black carbon (BC) instruments, and a CCN counter. We found that CCN activity of thickly coated BC is controlled by the chemical composition of water soluble compounds. The CCN activity of thinly coated BC is controlled by the thickness of the coating.B)Measurements of aerosol-cloud interactionWe conducted aircraft measurements of aerosol and cloud particles inside and outside of clouds located at 1-2 km near Japan in spring. We showed that thickly coated BC particles were taken up into clouds efficiently, consistent with the ground based measurements. This also s … More hows that BC can be a good tracer to quantitatively study aerosol-cloud interaction.C)Time constant of CCN formationWe showed that CCN activity of aerosol transported from the Asian continent within a few days is controlled mainly by the fraction of water soluble components from the data obtained in Jeju Island, Korea. Decrease in the surface tension of organic aerosol is also estimated to is contribute to the CCN activity. The CCN activity of various types of aerosol was measured also near Beijing. The observed CCN activity is consistent with the understandings obtained in Tokyo and Jeju Is.D)Calibration of the cloud probe and its aerodynamical characteristicsLight scattering cloud probe was calibrated using standard particles with high precision. We made aerodynamical calculations of airflows around the probe mounted on the aircraft and found high collection efficiency of cloud droplets.E)We calculated size distribution of cloud droplets predicted from various CCN concentrations using a trajectory model. Sensitivity of CCN-cloud interaction was estimated by the numerical experiments. Less