Campaign datasets for ARM Cloud Aerosol Precipitation Experiment (ACAPEX)

This campaign consisted of the deployment of the DOE ARM Mobile Facility 2 (AMF2) and the ARM Aerial Facility (AAF) G-1 in a field campaign called ARM Cloud Aerosol Precipitation Experiment (ACAPEX), which took place in conjunction with CalWater 2- a NOAA field campaign. The joint CalWater 2/ACAPEX field campaign aimed to improve understanding and modeling of large-scale dynamics and cloud and precipitation processes associated with ARs and aerosol-cloud interactions that influence precipitation variability and extremes in the western U.S. The observational strategy consisted of the use of land and offshore assets to monitor: 1. the evolution and structure of ARs from near their regions of development 2. the long-range transport of aerosols in the eastern North Pacific and potential interactions with ARs 3. how aerosols from long-range transport and local sources influence cloud and precipitation in the U.S. West Coast where ARs make landfall and post-frontal clouds are frequent.本次联合野外观测试验部署了美国能源部（Department of Energy, DOE）大气辐射测量（Atmospheric Radiation Measurement, ARM）移动设施2号（AMF2）与ARM航空设施（ARM Aerial Facility, AAF）G-1观测平台，所属试验项目为ARM云-气溶胶-降水试验（ARM Cloud Aerosol Precipitation Experiment, ACAPEX），该试验与美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）的野外观测试验项目CalWater 2协同开展。此次CalWater 2与ACAPEX联合野外观测试验，旨在深化对与大气河流（Atmospheric Rivers, ARs）相关的大尺度动力学过程、云与降水物理过程，以及气溶胶-云相互作用的认知与数值模拟能力；上述过程与相互作用会直接影响美国西部区域的降水变率与极端降水事件。本次观测策略依托陆基与近海观测资产，开展以下三方面监测：1. 大气河流从其生成区域附近起始的演变过程与结构特征；2. 北太平洋东部气溶胶的长距离传输特征，及其与大气河流的潜在相互作用；3. 长距离传输与本地排放源产生的气溶胶，如何在大气河流登陆且锋后云频发的美国西海岸区域，对云与降水过程产生影响。