Development of Balloon-Assisted Gliding Unmanned Aerial Vehicle System for Atmospheric Observation and Spatiotemporal Aerosol Variations in Summer Troposphere over Syowa Station

A novel aerosol observation and sampling system has been developed by combining a rubber balloon and an unmanned aerial vehicle (UAV). The system takes advantage of the feature of an observation method using a rubber balloon, which is handy, inexpensive, and higher reachable observation altitude than those of other observation methods, and the feature of a UAV which can fly back to the released point autonomously. In this system, an optical particle counter, an aerosol sampler, and a GPS sonde are mounted on a motor-glider UAV. The UAV, which is suspended from a rubber balloon, is released from the ground. After finishing observation and sampling during its ascent, the UAV is recovered by separating from the balloon and gliding back to the released point autonomously. Five observation flights were performed successfully at Syowa Station in the summer activity of the 54th Japanese Antarctic Research Expedition, and the maximum observation and separation altitude reached 10 km. Number concentrations obtained by insitu measurements and morphology of recovered aerosols using the UAV show the possibility that the enhancement of sulfate aerosols in the free troposphere and bottom of the stratosphere were caused by the volcanic eruption in the mid-latitude in January 2013.