Estimation of Aerosol Extinction Coefficient Using Camera Images and Application in Mass Extinction Efficiency Retrieval

Abstract

In this study, we attempted to calculate the extinction parameters of PM2.5 using images from a commercial camera. The photo pixels provided information on the characteristics of the objects (i.e., the reflectivity, transmittance, or extinction efficiency) and ambient brightness. Using the RGB values of pixels, we calculated the extinction coefficient and efficiency applied to the mass concentration of PM2.5. The calculated extinction coefficient of PM2.5 determined from the camera images had a higher correlation with the PM2.5 mass concentration (R2 = 0.7) than with the visibility data, despite the limited mass range. Finally, we identified that the method of calculating extinction parameters using the effective wavelength of RGB images could be applied to studies of changes in the atmosphere and aerosol characteristics. The mass extinction efficiency of PM2.5, derived from images, and the mass concentration of PM2.5 was (10.8 ± 6.9) m2 g−1, which was higher than the values obtained in Northeast Asia by previous studies. We also confirmed that the dry extinction efficiency of PM2.5, applied with a DRH of 40%, was reduced to (6.9 ± 5.0) m2 g−1. The extinction efficiencies of PM2.5, calculated in this study, were higher than those reported in previous other studies. We inferred that high extinction efficiency is related to changes in size or the composition of aerosols; therefore, an additional long-term study must be conducted.

Double Inversion Layers Affect Fog–Haze Events over Eastern China—Based on Unmanned Aerial Vehicles Observation

“…The concentration of PM can be related to RH [39,40]. As shown in Figures 2 and 3, the increase in RH in a short time could increase the concentration of PM (which is related to the hygroscopic growth of particles), while the high humidity environment (RH > 90%) for a long time (>12 h) decreased the concentration of particulate matter (wet scavenging effect).…”

Degradation of Commercially Available Digital Camera Images due to Variation of Rainfall Intensity in Outdoor Conditions

“…Further, Kim and Noh (2021) obtained the extinction coefficients of atmospheric aerosols from camera images and reported that the estimated range was 5.0 × 10 -5 to 1.0 × 10 -3 m -1 and the optimal aerosol extinction coefficient was approx. 5.0 × 10 -4 m -1 , and Shin et al (2022) reported that the range obtained from the camera images and visibility data was 2.0 ×10 -6 to 1.1 × 10 -3 m -1 . In reference to these reports, although there are differences in the air pollution conditions of the observation patches and the observation methods used, the value of atmospheric extinction coefficient is expected to be the order of 10 -6 to 10 -3 in m -1 unit, even if there is no rainfall, due to aerosol effects.…”

“…Because of the importance of atmospheric aerosols to air pollution and the human health impacts caused by it, traffic and airport safety, and climate change, many studies have been conducted to grasp the characteristics of aerosols (Kim & Noh, 2021). Some of these studies have reported on the relationship between atmospheric aerosols and atmospheric extinction coefficients (Kim & Noh, 2021;Ozkaynak et al, 1985;Shin et al, 2022;Uchiyama et al, 2014;Uchiyama et al, 2018). Ozkaynak et al (1985) calculated the values of extinction coefficient from the results of visibility observation in 12 airports at large cities in the U.S. and reported that they were 4.0 × 10 -5 -7.8 × 10 -4 m -1 .…”