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

拟建项目的目的是对极地大气边界层（ABL）中气溶胶粒子的垂直和水平分布进行实地调查。利用无人机系统（UAS）的原位方法研究了小尺度大气过程和气溶胶颗粒的变异性。它们扩大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架无人机。在DFG资助项目LA 2907/5-1， BA 1988/14-1， WI 1449/22-1的框架下，为新型UAS ALADINA开发了一种微型气溶胶测量系统，可检测8个粒径范围内的数量浓度。特别重要的是两个具有不同检测阈值的冷凝颗粒计数器的部署，可调节直径在5到20纳米之间，用于识别非常小的，最近形成的颗粒。另外两个MASC型无人机已装备用于测量ABL在水平飞行和垂直剖面上的湍流热力学性质（例如湍流通量），以及另外用于测量大颗粒数浓度。三个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三维图像。在之前的项目中，测量系统的部署允许表征气溶胶的变化，特别是在农村，大陆站点（Melpitz，德国）的新粒子形成的垂直动力学。研究表明，新粒子的形成通常始于ABL的顶部，粒子通过随后的对流混合向下输送，在那里它们可以用地面传感器观察到。这些已建立的系统现在将用于确定极地ABL（斯瓦尔巴群岛新奥勒松）的气溶胶变化，背景是地面和齐柏林天文台（470米）的连续地面原位和遥感观测。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）到夏季可能较小的、局部形成的颗粒。小尺度高度可变的地形改变了气溶胶的分布，并产生了局部效应，如特殊的风系统（沿着峡湾）。进一步利用粒子成核的观测数据进行数值研究，以提高对极区粒子成核的认识。

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.