High Resolution, Active Remote Sensing of Cloud Microphysics at Summit, Greenland with Polarized Raman Lidar

更好地了解北极云和气溶胶的性质、结构和形成对于了解北极在全球气候变化背景下的具体反应至关重要。由于缺乏对云粒子、气溶胶、水汽平流（即水蒸气）和热力学的一致的高垂直和时间分辨率观测，目前的模式对云性质的估计存在很大的不确定性，并抑制了我们对云辐射和降水对地面影响的理解。因此，目前的天气和气候模式不能很好地参数化北极，特别是格陵兰冰盖（GIS）上的云层。减少这种不确定性在地理信息系统上空尤为重要，因为云层通过调节地表辐射收支和可利用的可降水量，充当冰质量平衡的汇和源。为了获得减少这种不确定性所需的理解，提出了一种新的自主多波长偏振拉曼激光雷达，用于在nsf进行开发和部署。这是位于格陵兰Summit的美国天文台。新的激光雷达观测将采用多种波长和极化来观测北极大气的弹性和非弹性散射，从而能够定期检索温度、水蒸气和消光剖面。这种观测能力的结合将创建一个通过北极对流层和峰顶上方平流层的高分辨率热力学、云和气溶胶观测的连贯数据集。总的来说，作为更大的北极观测网的一部分，格陵兰峰会上的这个国家科学基金会观测站的增加与北极环境变化研究（SEARCH）实施计划非常契合。因此，该仪器将显著加强北极观测基础设施，并推进对北极变化的观测和了解。拟议的仪器和观测是GIS上的第一个此类仪器和观测，并将扩大现有的（尽管规模不大）横跨北极的此类测量网络。该项目还将通过实地考察和后续数据处理的结合，为科罗拉多大学的研究生提供独特的体验和教育机会。

A better understanding of Arctic cloud and aerosol properties, structure and formation is essential to understand the specific response of the Arctic in the context of global climate change. A lack of coherent high vertical and temporal resolution observations of cloud particles, aerosols moisture advection (i.e. water vapor) and thermodynamics, creates large uncertainties in current model estimates of cloud properties and inhibits our understanding of cloud radiative and precipitation impacts on the surface. As a result, current weather and climate models poorly parameterize clouds over the Arctic and more specifically over the Greenland Ice Sheet (GIS). A reduction in this uncertainty is particularly important above the GIS, where clouds act as sinks and sources to the ice mass balance by modulating the surface radiation budget and available precipitable water. To gain the understanding necessary to reduce this uncertainty, a new autonomous multi-wavelength, polarized Raman lidar is proposed for development and deployment at the NSFʼs observatory in Summit, Greenland. The new lidar observations will employ multiple wavelengths and polarizations to observe elastic and inelastic scattering from the Arctic atmosphere enabling regular retrieval of temperature, water vapor and extinction profiles. This combination of observational capability will create a coherent dataset of high-resolution thermodynamic, cloud and aerosol observations through the Arctic troposphere and lower stratosphere above Summit. Broadly, this addition to the NSF Observatory at Summit, Greenland as part of the larger Arctic Observing Network fits well within the Study of Environmental Arctic Change (SEARCH) implementation plan. Thus, this instrument will significantly enhance Arctic observing infrastructure and advance observations and understanding of change in the Arctic. The proposed instrumentation and observations are the first of their kind on the GIS and will expand the existing, although modest, network of such measurements across the Arctic. This project will also provide a unique experience and educational opportunity through the combination of fieldwork and subsequent data processing for graduate students at the University of Colorado.