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。缺乏对云粒子、气溶胶水汽平流(即水汽)和热力学的一致的高垂直和时间分辨率观测，给当前云特性的模式估计带来了很大的不确定性，并阻碍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型对北极上空的云，更具体地说是格陵兰冰盖(地理信息系统)的云，没有很好的参数化。减少这种不确定性在地理信息系统之上尤为重要，在地理信息系统中，云通过调节地表辐射收支和可用可降水量，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，一种新的自主多波长、偏振拉曼激光雷达被提议在格陵兰岛顶峰的美国国家科学基金会S天文台进行开发和部署。新的激光雷达观测将使用多个波长和偏振来观测北极大气的弹性和非弹性散射，从而能够定期反演温度、水蒸气和消光轮廓。这种观测能力的结合将通过顶峰上方的北极对流层和低平流层建立一个高分辨率热力学、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络的一部分，格陵兰岛顶峰的NSF观测站的这一补充非常符合北极环境变化研究(SEARCH)实施计划。因此，该仪器将大大加强北极观测基础设施，促进对北极变化的观测和了解。拟议的仪器和观测是地理信息系统上的第一个此类仪器和观测，将扩大整个北极现有的此类测量网络，尽管规模不大。该项目还将通过实地考察和随后的数据处理相结合的方式，为科罗拉多大学的研究生提供独特的经验和教育机会。

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.