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

有效云凝结核数是影响云滴数浓度和云滴谱分布等云微物理特性的重要参数。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。目前的气候模型往往基于有关云凝结核数浓度和其他与云凝结核有关的特性（如吸湿性）的假设，因为缺少地球仪大面积区域的代表性数据。如果存在的话，云凝结核及其特性的测量通常是在近地面进行的，因此除了山区以外，不在与云形成过程有关的高度进行。然而，对于加勒比海的混合良好的海洋边界层，据观察，陆基云凝结核的特性似乎也代表了云的形成区域。在这个拟议的项目中，我们希望评估地面CCN测量是否具有代表性，如果是，在何种条件下，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中检验加勒比地区调查结果的有效性，即：海洋和大陆环境。关于海洋环境，计划在亚速尔群岛（葡萄牙）开展测量活动。我们将结合联合收割机连续可用的CCN数据从亚速尔群岛东北大西洋（ENA）网站在格拉西奥萨岛（在海平面）与运动明智的测量在山。皮科站（皮科岛，海拔2225米），CCN以及机载测量平台ACTOS（机载云湍流观测系统）上的CDNC测量，以缩小海平面和山址数据之间的垂直差距。在ACTRIS（气溶胶云和痕量气体研究气溶胶结构网络）Melpitz站连续进行大陆地面云凝结核测量。垂直CCN和CDNC分布将在梅尔皮茨进行测量，在项目的三年时间框架内，通过气球发射的方式，每个季节进行一次为期一周的活动。此外，我们将通过利用气溶胶-云相互作用（ACI）度量定量连接云下原位测量的CCN属性（即数量和吸湿性）到云内原位测量的CDNC。将利用由真实的大气测量数据驱动的云块模型进行敏感性研究，从而深入了解新形成的真实的云的过饱和状态。收集的数据本身，对CCN属性及其垂直分布的预期见解，以及CCN和CDNC之间的预期定量联系，将在理解和建模云滴激活和云微物理属性的背景下具有重要价值，例如，气候模型

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.