Investigating the Small-Scale Vertical and Horizontal Variability of the Atmospheric Boundary Layer Aerosol using Unmanned Aerial Vehicles

拟议项目的目的是实地调查极地大气边界层(ABL)中气溶胶颗粒的垂直和水平分布。利用无人驾驶航空系统(UAS)的现场方法研究了小尺度大气过程和气溶胶颗粒的可变性。它们扩展了气溶胶调查的能力，填补了连续的地面观测和广泛的飞机测量之间的空白。该项目将同时使用三个无人机。在DFG资助的项目LA 2907/5-1，BA 1988/14-1，WI1449/22-1的框架下，为新的UAS ALADINA开发并表征了一种小型气溶胶测量系统，可在八个颗粒尺寸范围内检测数字浓度。特别重要的是部署了两个具有不同检测阈值的凝聚颗粒计数器，直径在5到20 nm之间可调，用于识别非常小的新近形成的颗粒。另外两个MASC类型的无人机已装备用于在水平飞行和垂直剖面上测量ABL的湍流热力学性质(例如湍流通量)，此外还用于测量更大的颗粒数浓度。三种无人机的不同飞行模式同时提供了大气参数和气溶胶分布的3D图像。通过在上述项目期间部署测量系统，可以表征气溶胶的可变性，特别是农村大陆站点新颗粒形成的垂直动态(梅尔皮茨，德国)。结果表明，新的粒子形成通常从ABL的顶部开始，粒子通过随后的对流混合向下输送，在那里可以用地面传感器观察到它们。这些成熟的系统现在将用于确定极地ABL(NY-Alesund，Svalbard)的气溶胶可变性，并在地面和齐柏林天文台(470米)进行连续的地面现场和遥感观测。特别令人感兴趣的是气溶胶性质的转变，从春季相当大的、老化的气溶胶颗粒(北极雾霾)到夏季可能在当地形成的小颗粒。小尺度高度多变的地形改变了气溶胶的分布，并产生了局部效应，如沿峡湾的特殊风系统。进一步将观测到的粒子成核数据用于数值研究，以提高对极区粒子成核的理解。

The aim of the proposed project is the in situ investigation of the vertical and horizontal distribution of aerosol particles in the polar atmospheric boundary layer (ABL). Small-scale atmospheric processes and the variability of aerosol particles are investigated using an in situ approach by unmanned aerial systems (UAS). They expand the capabilities for aerosol investigation and fill the gap between continuous ground-based observations and extensive aircraft measurements. This project will use three UAS simultaneously. A miniature aerosol measurement system, detecting the number concentration in eight particle size ranges, has been developed and characterized for the new UAS ALADINA in the framework of the DFG funded project LA 2907/5-1, BA 1988/14-1, WI 1449/22-1. Of special importance is the deployment of two condensation particle counters with different detection threshold, adjustable for diameters between 5 and 20 nm, for identification of very small, recently formed particles. The two other UAS of type MASC have been equipped for measurements of the turbulent thermodynamic properties of the ABL (e.g. turbulent fluxes) on horizontal flights and vertical profiles, and additionally for measuring larger particle number concentration. Different flight pattern of the three UAS simultaneously provide a 3D picture of atmospheric parameters and the aerosol distribution. The deployment of the measurement systems during the preceding projects allowed the characterization of aerosol variability and especially the vertical dynamics of new particle formation at a rural, continental site (Melpitz, Germany). It was shown that new particle formation starts typically at the top of the ABL, and particles are transported downwards by subsequent convective mixing, where they can be observed with ground-based sensors.The well-established systems will now be used to determine the aerosol variability in the polar ABL (Ny-Alesund, Svalbard), with the background of continuous ground-based in situ and remote sensing observations at ground level and at the Zeppelin observatory (470 m). Of special interest is the transition of aerosol properties from rather large, aged aerosol particles in spring (Arctic haze) to presumably small, locally formed particles in summer. The small-scale highly variable orography modifies the distribution of aerosol, and local effects like special wind systems (along the fjord) occur. The observed data of particle nucleation are further used for numerical studies to improve the understanding of the particle nucleation in polar regions.