Airborne Observations of Environmental Flows: Boundary-Layer Structure, Aerosol–Cloud Interactions, and Cloud Microphysics
Dr. Fan Mei is an Earth Scientist at PNNL specializing in atmospheric science and technology.
Abstract: Environmental flows in the lower atmosphere govern the transport of heat, moisture, aerosols, and cloud condensate, linking boundary-layer turbulence to cloud formation, radiative exchange, precipitation, and the hydrologic cycle. Understanding these coupled processes requires observations that resolve atmospheric heterogeneity from particle to regional scales. This seminar will discuss how airborne and tethered measurements from the DOE Atmospheric Radiation Measurement (ARM) user facility support process-level studies of environmental flows, aerosol–cloud interactions, and water-cycle variability. ARM has provided more than three decades of atmospheric measurements from all seven continents and five oceans, serving about 1,000 scientific users annually. A central example is an integrated dataset from the final six years of ARM Aerial Facility Gulfstream-1 aircraft operations (2013–2018), comprising 236 flights and 766.4 flight hours across the Arctic, the U.S. Southern Great Plains, the U.S. West Coast, the Eastern North Atlantic, the Amazon Basin, and the Sierras de Córdoba. These data resolve the spatiotemporal variability of thermodynamic quantities, aerosol states, and cloud properties, enabling process-level studies of boundary-layer heterogeneity and land–atmosphere coupling. The talk will also highlight newer ARM aerial capabilities, including the Tethered Balloon System and ArcticShark Uncrewed Aerial System. ArcticShark has accumulated 462 flight hours and can sample below and above clouds up to 15,400 ft MSL. Finally, I will introduce our newly developed holographic imaging instrument, which resolves cloud particle size, spatial distribution, and microphysical variability in turbulent flows, bridging platform-scale observations and the microscale processes that control aerosol–cloud interactions, entrainment, and precipitation. Together, these evolving capabilities and ARM's standardized datasets advance model evaluation, machine learning, and process understanding of environmental flows and cloud–hydrology coupling.
About: Dr. Fan Mei is an Earth Scientist at PNNL specializing in atmospheric science and technology. Her expertise encompasses the physical and chemical properties of aerosols, instrumentation, and the characterization of aerosol and cloud properties. As the science lead and payload scientist for multiple DOE ARM Aerial Facility (AAF) field campaigns, she has decades of hands-on experience advancing atmospheric research using innovative aerial platforms, including piloted aircraft, the ARM UAS ArcticShark, and the ARM Tethered Balloon System (TBS). Recently, Dr. Mei has focused on applying AI/ML techniques to earth system observation, accelerating the analysis of complex datasets and improving operational efficiency in atmospheric research and monitoring.