Copter-Type UAV-Based Sensing in Atmospheric Chemistry: Recent Advances, Applications, and Future Perspectives.

Copter-type unmanned aerial vehicles (UAVs) have emerged as cutting-edge platforms for environmental research, offering rapid and cost-effective solutions for atmospheric sensing and sampling. This review highlights recent advancements and explores future prospects for their application in atmospheric chemistry. The UAV-based techniques have demonstrated excellent capabilities in characterizing the spatial distribution of gaseous pollutants using both real-time, low-cost sensors, and offline analytical methods. These platforms have also proven effective in profiling the physicochemical properties of airborne particulate matter, providing insights into its sources, chemical transformation, and environmental and climate impacts. In regard to the applications, this review underscores the diverse roles of UAVs related to atmospheric chemistry, including emission characterization (e.g., forest volatile and bioaerosol emissions), hazard assessment (e.g., wildfire and volcanic plume monitoring), and meteorology and climate research (e.g., aerosol-cloud interactions). The review also addresses key challenges in current UAV techniques, such as payload and battery limitations, regulatory constraints, propeller-induced disturbances, and explores emerging directions, such as UAVs in biosphere-atmosphere interactions and indoor air quality monitoring. Overall, UAVs are reshaping atmospheric chemistry research by providing high-resolution spatial data sets that complement traditional methods. These advancements further enhance our understanding of atmospheric processes and facilitate the development of precise and adaptable environmental monitoring strategies.