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

众所周知，陨石烟雾粒子(MSP)是由流星体进入大气层时外星物质重新凝结而成的。它们对夜光云的形成至关重要，因为它们是夜光云的核心。它们经历了沉积/平流，并主要在冬季涡旋中下沉到较低的海拔，因此在平流层硫酸盐颗粒中也发现了它们。尽管MSP对于平流层的物理和化学非常重要，但对MSP的许多方面还没有或没有得到足够的了解。原因在于检测MSP的难度极大。对于激光雷达测量，由于气溶胶与瑞利后向散射信号之比只有[10]^(-3)左右，因此很难探测到MSPS。在卫星测量中也很难检测到MSP，因为卫星测量中可能的MSP签名仍然不明确。因此，这项提议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来调查MSP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)和格雷夫斯瓦尔德大学(UG)在这一领域拥有卓越的专业知识。IAP是世界上为数不多的在激光雷达技术领域进行“中层大气研究”的机构之一，因此也是能够进行温度、风、湍流和气溶胶测量的领先研究机构之一。在冯·萨维尼教授的帮助下，UG在被动卫星测量的中层大气气溶胶方面拥有20多年的经验。该提案分为4个主题：(1)在高纬度平流层气溶胶的独特激光雷达测量中识别MSP。为此，我们使用了戴维斯(69°S)和挪威(69°N)的现有测量结果。利用这些在Junge层上方的气溶胶测量，我们研究了极涡中MSP的沉积。(2)我们验证了在过去和现在的卫星测量中可以观测到MSPs，并且这些结果与激光雷达的观测结果一致。(3)显著提高了激光雷达测量的灵敏度。为此，利用新型激光雷达系统VAHCOLI探测了上平流层/下中间层的MSP。此外，我们还进行了退极化测量，以表征粒子的形状。我们将新的VAHCOLI测量方法与已建立的平流层气溶胶观测方法(Alomar多色激光雷达，IAP)进行了比较，该方法提供了粒子大小和数密度。(4)对WACCM模式与模式模拟进行季节性比较，检验WACCM模式对观测MSP特征的再现能力。

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.