Observations of meteoric smoke particles in the middle atmosphere with a novel lidar method. (O-MSP-LI)

众所周知，流星烟雾粒子（MSP）是由流星体进入大气层时地外物质的重新凝聚形成的。它们作为夜光云的成核，对夜光云的形成起着至关重要的作用。它们主要在冬季涡旋中沉降/平流并下沉到较低的高度，因此它们也存在于平流层硫酸盐颗粒中。尽管MSPs对平流层的物理和化学非常重要，但MSPs的许多方面还没有或没有得到充分的了解。原因在于检测msp极其困难。对于激光雷达测量，由于气溶胶与瑞利背散射信号的比值仅在〖10〗^（-3）左右，因此msp很难被探测到。在卫星测量中也很难检测到MSP，因为卫星测量中可能的MSP特征仍然不明确。因此，本提案的科学目标是利用一种新的激光雷达方法结合现有的卫星测量，研究MSPs的空间和季节存在以及它们与Junge层的分离。莱布尼茨大气物理研究所（IAP）和格赖夫斯瓦尔德大学（UG）在这一领域拥有出色的专业知识。IAP是世界上为数不多的用于“中层大气研究”的激光雷达技术研究机构之一，因此是能够进行温度、风、湍流和气溶胶测量的领先研究机构之一。在冯·萨维尼教授的协助下，研究组从被动卫星测量中获得了20多年研究中层大气气溶胶的经验。本提案分为4个主题：(1)高纬度平流层气溶胶独特激光雷达测量中的MSP识别。为此，我们使用了戴维斯（69°S）和挪威（69°N）的现有测量数据。在先前激光雷达无法到达的海拔高度范围内，通过这些在丛林层以上的气溶胶测量，我们研究了极地涡旋内msp的沉积。(2)我们验证了在过去和当前的卫星测量中可以观测到msp，并且这些观测结果与激光雷达观测结果一致。(3)显著提高了激光雷达测量的灵敏度。为此，使用新型激光雷达系统VAHCOLI探测平流层上层/中间层下层的MSPs。此外，我们还进行了退极化测量来表征粒子形状。我们将新的VAHCOLI测量结果与提供颗粒大小和数量密度的平流层气溶胶观测方法（ALOMAR多色激光雷达，IAP）进行了比较。(4)通过将所有可用测量值与模型模拟值进行季节性比较，我们测试了WACCM模型重现观测到的MSP特性的能力。

Meteoric smoke particles (MSP) are known to be formed by recondensation of extraterrestrial material as meteoroids enter the atmosphere. They are of crucial importance for the formation of noctilucent clouds (NLCs) since they act as their nucleation nuclei. They undergo sedimentation/advection and sink to lower altitudes mainly in the winter vortex, so they are also found in stratospheric sulfate particles. Despite the great importance of MSPs for the physics & chemistry of the stratosphere, many aspects of MSPs are not or are insufficiently understood. The reason lies in the extreme difficulty to detect MSPs. For lidar measurements, MSPs are difficult to detect because the aerosol to Rayleigh backscatter signal ratio is only around 〖10〗^(-3). MSPs are also difficult to detect in satellite measurements, as possible MSP signatures in satellite measurements are still ambiguous. As a result, the scientific goal of this proposal is to investigate the spatial and seasonal existence of MSPs and their separation from the Junge layer using a novel lidar method in combination with available satellite measurements. The Leibniz Institute for Atmospheric Physics (IAP) and the University of Greifswald (UG) have excellent expertise in this field. The IAP is one of the world's few institutes in the field of lidar technology for "Middle Atmosphere Research" and thus one of the leading research institutes that can carry out temperature, wind, turbulence, and aerosol measurements. With Prof. von Savigny, the UG has more than 20 years of experience with aerosols in the middle atmosphere from passive satellite measurements. The proposal is separated into 4 topics: (1) The MSP identification in unique lidar measurements of stratospheric aerosols at high latitudes. For this, we use existing measurements from Davis (69° S) and Norway (69° N). With these aerosol measurements above the Junge layer in an altitude range previously not accessible with lidar, we investigate the sedimentation of MSPs within the polar vortex. (2) We verify that MSPs are observable in past and current satellite measurements and that these agree with lidar observations. (3) We significantly improve the sensitivity of lidar measurements. For this purpose, MSPs in the upper stratosphere/lower mesosphere are detected with the novel lidar system VAHCOLI. In addition, we carry out depolarization measurements to characterize the particle shape. We compare new VAHCOLI measurements with an established method of stratospheric aerosol observation (ALOMAR multicolor lidar, IAP) that provides particle size and number density. (4) We test the ability of the WACCM model to reproduce the observed MSP properties by seasonally comparing all available measurements with model simulations.