Vertical Distribution Of Cloud Condensation Nuclei In Marine And Continental Air Masses Over Europe And Their Connection To The Cloud Droplet Number Distribution In Warm Clouds

可用云凝结核数（CCN）是影响云微物理性质如云滴数浓度（CDNC）和尺寸分布的重要参数。CDNC和液滴大小控制云的辐射特性和寿命，导致地球能量平衡中的复杂反馈。目前的气候模式通常基于有关CCN数量浓度和其他CCN相关性质（如吸湿性）的假设，因为全球广大地区缺乏具有代表性的数据。如果存在，CCN及其性质的测量通常是在近地面进行的，因此，除了山区地点外，不在与云形成过程有关的高度进行。然而，对于加勒比海混合良好的海洋边界层，观察到地面的CCN特性似乎也具有云形成区域的代表性。在这个提议的项目中，我们想评估地面CCN测量是否具有代表性，如果是，在什么条件下，对于云的形成水平，这将大大简化CCN数据在模型中的应用。因此，应在两种截然不同的环境，即海洋环境和大陆环境中检验加勒比地区结论的有效性。关于海洋环境，计划在亚速尔群岛（葡萄牙）进行一次测量运动。我们将结合亚速尔群岛东北大西洋（ENA）站点在Graciosa岛（海平面）的连续可用CCN数据与Pico山站（Pico岛，海拔2225米）的活动测量数据，以及直升机机载测量平台ACTOS（机载云湍流观测系统）上的CCN和CDNC测量数据，以缩小海平面和山区数据之间的垂直差距。大陆地面CCN测量是在Melpitz的ACTRIS（气溶胶云和微量气体研究基础设施网络）站连续进行的。CCN和CDNC的垂直分布将在Melpitz进行测量，在项目的三年时间框架内，每个季节进行几次为期一周的活动。此外，我们将通过利用气溶胶-云相互作用（ACI）度量，定量地将下面云中原位测量的CCN特性（即数量和吸湿性）与云中原位测量的CDNC联系起来。利用真实大气测量驱动的云包模型进行敏感性研究；从而深入了解新形成的真实云的过饱和状态。收集到的数据本身，对CCN性质及其垂直分布的预期见解，以及CCN和CDNC之间预期的定量联系，将在理解和模拟云滴活化和云微物理性质的背景下具有重要价值，例如气候模式。

The number of available cloud condensation nuclei (CCN) is an important parameter influencing cloud microphysical properties such as cloud droplet number concentration (CDNC) and size distribution. CDNC and droplet size control cloud radiative properties and lifetime leading to a complex feedback in the earths energy balance. Current climate models are often based on assumptions concerning CCN number concentrations and other CCN related properties (e.g. hygroscopicity), as for wide areas of the globe representative data are missing. If existing, measurements of CCN and their properties are usually performed near ground and thus not, with the exception of mountain sites, in the altitude relevant for cloud formation processes. For the well-mixed marine boundary layer in the Caribbean it was however observed that ground based CCN properties seem to be representative also for the cloud forming regions. In this proposed project we want to evaluate if ground-based CCN measurements are representative, and if yes under which conditions, for the level of cloud formation, which would simplify the application of CCN data in models strongly. Thereto, the validity of the finding in the Caribbean shall be tested for two contrasting environments, i.e., a marine and a continental environment. Concerning the marine environment, a measurement campaign on the Azores archipelago (Portugal) is planned. We will combine continuous available CCN data from the Azores Eastern North Atlantic (ENA) site at Graciosa Island (at sea level) with campaign wise measurements at Mt. Pico station (Pico Island, 2225 m asl), and CCN as well as CDNC measurements on the helicopter-borne measurement platform ACTOS (Airborne Cloud Turbulence Observation System) to close the vertical gap between sea level and mountain-site data. The continental ground-based CCN measurements are carried out continuously at the ACTRIS (Aerosols Clouds and Trace gases Research InfraStructure network) station Melpitz. The vertical CCN and CDNC distribution will be measured at Melpitz in several one-week campaigns once per season by means of balloon launches within the three year time frame of the project. Furthermore we will quantitatively connect via the utilization of the aerosol-cloud interaction (ACI) metric the below cloud in-situ measured CCN properties (i.e. number and hygroscopicity) to in-cloud in-situ measured CDNC. A sensitivity study with a cloud parcel model driven by the real atmospheric measurements will be carried out; thereby gaining insight into the supersaturation regimes of freshly formed real clouds. The collected data itself, the expected insights into CCN properties and their vertical distributions, and the envisioned quantitative connection between CCN and CDNC will be of great value in the context of understanding and modeling cloud droplet activation and cloud microphysical properties in, e.g., climate models.