Arctic Cloud and Aerosol Remote Sensing Research at Arctic Facility for Atmospheric Remote Sensing (AFARS)

北极云通过调节高纬度地区的辐射平衡，对当地和全球气候和天气产生重大影响，但人们对此还不是很清楚。该地区的气溶胶输送可能对云的形成和微物理性质有很大影响，因为该地区与气象隔绝，缺乏当地的气溶胶来源，而且一年中的大部分时间都会遇到原始的空气质量条件。气候变化有望在极地地区特别明显，北极云可能特别容易受到全球变暖的影响，因此有可能提供额外的气候反馈。正如即将开展的国际极地年研究工作所确认的那样，我们必须改进对大气状况的了解。阿拉斯加大学费尔班克斯北极大气遥感设施(AFARS，北纬64.86度，西经147.84度)将进行一项综合遥感测量计划，以减少我们对北极云和气溶胶特性的不确定性，特别是研究气溶胶对云的间接影响。阿法斯有三个工作在0.532、0.694、1.06和1.574微米的偏振激光雷达，一个0.607微米的氮拉曼通道，一个偏振多普勒W波段(3.2毫米)雷达，以及一套紫外线、可见光和红外辐射计。与以往的中纬度研究一样，AFARS观测将在天桥期间与地球观测系统A系列卫星的观测相协调。具体目标是使用多个地面和空间遥感传感器来描述我们区域中高层云的宏观物理和微观物理特性，并将它们与中纬度云进行比较；研究气溶胶侵入受极锋屏障保护的正常清洁的北极环境，同时通过组合多波长去偏振、斯托克斯参数化和拉曼激光雷达方法改进气溶胶表征；更深入地研究最近的发现，如输送的亚洲尘埃、火山尘埃和森林火灾烟雾等气溶胶正在间接影响云；并测试卫星方法表征我们观察到的云和气溶胶的能力。这个项目的智力优势在于，它将基于大学的独特遥感仪器集合与地球上一个基本上未被研究的地区的卫星数据相匹配，为基本的新发现提供了机会。通过学生和博士后科学家的参与，产生了更广泛的影响。新科学家将在遥感领域接受培训。更广泛地说，这项研究涉及北极气候变化的过程和影响。

Arctic clouds have a significant impact on local and global climate and weather through modulating the radiation balance at high latitudes but are yet not very well understood. Aerosol transport to this region probably has a large influence on cloud formation and microphysical properties because of the region's meteorological isolation, lack of local aerosol sources, and the pristine air quality conditions encountered for much of the year. Climate change promises to be particularly evident in polar regions, and Arctic clouds may be particularly susceptible to the effects of global warming, thus providing the potential for additional climatic feedbacks. Our knowledge of atmospheric conditions must be improved as recognized by the upcoming International Polar Year research effort. A comprehensive remote sensing measurement program from the University of Alaska Fairbanks Arctic Facility for Atmospheric Remote Sensing (AFARS, at 64.86 deg N and 147.84 deg W) will be conducted to lessen our uncertainties about Arctic cloud and aerosol properties, and particularly to examine aerosol indirect effects on clouds. AFARS has three polarization lidars operating at 0.532, 0.694, 1.06 and 1.574 micrometers, a 0.607 micrometer nitrogen Raman channel, a polarimetric Doppler W-band (3.2-mm) radar, and a suite of ultraviolet, visible, and infrared radiometers. As in previous midlatitude studies, AFARs observations will be coordinated with observations by Earth Observing System A-train satellites during overpasses.The specific goals are to use multiple remote sensors, both ground- and space-based, to characterize the macrophysical and microphysical properties of mid- and high-level clouds in our region and to compare them to their midlatitude counterparts; study aerosol intrusions into the normally clean Arctic environment protected by the barrier of Polar Fronts, and at the same time improve aerosol characterization through combined multi-wavelength depolarization, Stokes parameterization, and Raman lidar methods; more intensively study recent findings that aerosols, such as transported Asian dust, volcanic dust, and forest fire smoke, are indirectly affecting clouds; and test the ability of satellite methods to characterize the clouds and aerosols we observe.The intellectual merit of this program is that it matches a unique ensemble of university-based remote sensing instruments with satellite data in a largely unstudied part of the globe, offering the chance for fundamental new discoveries. The broader impacts arise through student and postdoctoral scientist involvement. New scientists will be trained in the remote sensing arena. Even more broadly, the research addresses processes and impacts of climate change in the Arctic.