Recently, the research group of Professor ZHANG Weijun from Anhui Institute of Optics and Fine Mechanics (AIOFM), Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences (CAS), achieved in-situ measurement of aerosol single scattering albedo (SSA) vertical profile for the first time.
The relevant research work was published in Optics Express.
Aerosol SSA (the ratio of scattering to extinction coefficient) is a key input parameter in evaluating radiative forcing. Measuring the vertical profile of SSA is of great significance to understand aerosol radiation interaction and aerosol atmospheric boundary layer feedbacks. However, direct measurement of SSA vertical profile remains challenging. Although some aircraft observations have been carried out, there is still large uncertainty. It is urgent to develop a new instrument for detecting the SSA vertical profile accurately.
In order to obtain the SSA vertical profile, in this research, a new custom cage-based optical system, and high-precision temperature and current controller were adopted to solve the influence of vibration and temperature changes during flight. Further combined with self-producing gas source and independent power supply, the unmanned-aerial-vehicle-borne cavity-enhanced albedometer (CEA) was developed.
Compared with the first CEA developed by the team in 2014, this system was improved in many aspects. It consisted of a petrol-powered hexacopter (with a load of 40 kg and endurance time of more than one hour) and a miniaturized CEA, and was equipped with various auxiliary probes including of a micro-aethalometer, an aerosol optical particle sizer, and an ozone sensor.
Now the system had been successfully applied to the comprehensive observation experiment of aerosol optical vertical profiles at Shouxian National Climatological Observatory from 2020 to 2021, which can provide valuable and unique tool and accurate observation data for studying the optical characteristics of aerosols and their influence on physical and chemical processes in the atmospheric boundary layer.
The structure diagram of custom cage-based optical system used in UAV-CEA (Image by ZHOU Jiacheng)
The picture of UAV-CEA (Image by ZHOU Jiacheng)