Decade-low aerosol levels over the Bohai and Yellow Seas amid the COVID-19 lockdown

• DOI: 10.1016/j.jag.2022.102905
• Publication Date: 2022-07-08T23:28:46Z
• Authors: RunaA; Tingwei Cui; Song Qing; Ting Wei; Bing Mu; Yanfang Xiao; Yanlong Chen; Yuhai Bao; Jie Zhang
• Keywords: HYSPLIT; Moderate-resolution imaging spectroradiometer

Coronavirus disease 2019 (COVID-19) has crucially influenced anthropogenic activities, which in turn impacts upon the environment. In this study, we investigated variations on aerosol optical depth (AOD) at 550 nm over Bohai Sea and Yellow during COVID-19 lockdown (from February to March 2020) of China mainland based Moderate-resolution Imaging Spectroradiometer (MODIS) observation by comparing with historical AOD records (2011-2019). Our results show that implementation, decade-low levels are achieved 2020 (0.39 ± 0.18 0.37 0.19, respectively), 22% 28% (p < 0.01) lower than average between 2011 (0.50 0.08 0.52 0.05, respectively). After restrictions were relaxed industrial production gradually resumed, April rebounded level. Besides, compared observations (2011-2019), temporal variability from showed different pattern, decade-high increase (+0.11) (-0.01). Independent simulation, including fine particulate matter (PM2.5) ground-based measurements, wind field Cross-Calibrated Multi-Platform, satellite-derived type, back trajectories calculation Hybird Single Paricle Lagrangian Intergrated Trajectory (HYSPLIT) model, indicated above abnormal variation can be attributed reduction emissions period. The paper, therefore, indicate aerosols Seas strongly human public health events such as epidemic may alter intensity activities thus spatio-temporal pattern ocean. With global spread corresponding significant changes behavior patterns (restrictions etc.), more studies should carried out future about its potential impact marine