Research on detection technology of photolysis rate of atmospheric trace gases

¹ College of Biology, Food and Environment, Hefei University, Hefei, Anhui 230601, China
² Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Precision Machinery, Chinese Academy of Sciences, Hefei, Anhui 230031, China
³ University of Science and Technology of China, Hefei, Anhui 230036, China

^* Corresponding author: sifuqi@aiofm.ac.cn

Abstract

A detection system for measuring the optical velocity of trace gases was built based on a micro-spectrometer, including an optical receiver, a radiation calibration system, a spectrometer system, and a host computer software. Using Python language and PyQt5 framework, the system’s host computer software was designed and developed, including the data collection and spectrometer control module storage module, and the real-time data display module for online continuous monitoring of the photolysis rate. Through field experiments, the photolysis rates of NO₂, O₃, H₂O₂, HONO, and HCHO were measured and inverted. The photolysis rate measurement results were compared and verified with a standard instrument ( UF-CCD photolysis spectrometer produced by Metcon, Germany ). The results show that the photolysis rate measurement system and the standard instrument results are linearly fitted, and R ² is both higher than 0.90. At the same time, the diurnal variation patterns of NO₂, HONO, and H₂O₂ were analyzed. The results showed that the pattern of gas photolysis rate was consistent with changes in solar radiation intensity. The gas photolysis rate gradually increased in the morning, reached a peak at noon, and then reached a peak in the afternoon. gradually decreases. By analyzing the uncertainty of the system, the total system error is approximately 5.07 %. The feasibility and measurement accuracy of the developed photolysis rate measurement system were verified.