Impact of decreased aerosols during the COVID-19 pandemic on winter wheat gross primary productivity and water use efficiency

Rapid and comprehensive lockdowns to contain the coronavirus 2019 (COVID-19) pandemic reduced anthropogenic emissions and, thereby, decreased the aerosol optical depth (AOD) in Xiangyang, Hubei Province. However, their complicated interactions make quantifying the contribution of decreased aerosols to crop growth challenging. Here, we explored the indirect effects of decreased aerosol concentrations on the gross primary productivity (GPP) and water use efficiency (WUE) of winter wheat by quantifying the contributions of key environmental factors. Our results showed high temporal and spatial associations between aerosols (represented by AOD), GPP, and WUE before, during, and after the COVID-19 pandemic. AOD decreased by 23.8% +/- 10.1%, whereas GPP and WUE increased by 16.5% +/- 5.8% and 17.0% +/- 15.3%, respectively. The GeoDetector model revealed that photosynthetically active radiation (PAR) had a major impact on GPP and WUE, followed by precipitation, surface soil moisture, subsurface soil moisture, and surface temperature. Moreover, causality analysis showed a causal relationship between AOD and the dominant factors (PAR and precipitation) during the lockdown, thereby indicating a positive effect of decreased aerosols on GPP and WUE changes of winter wheat. Our findings assist in understanding the mechanisms causing GPP and WUE changes, given the environmental factors that changed significantly during the pandemic. (c) 2022 Society of Photo-Optical Instrumentation Engineers (SPIE)

The Warning and Governance of Online Public Opinion Research

Scientific, timely and effective health communication is crucial for stabilizing public emotions and taking effective prevention and control actions during the crisis of 2019-nCoV. This article uses Qualitative Comparative Analysis (QCA) and takes the health rumors list during the epidemic as a research sample to determine 6 specific explanatory condition variables and analyze the combination factors that affect the spread of high-health rumors in health. From the perspective of public opinion, including evolution mechanism, generation mechanism, and early warning mechanism, it aims to propose the perfection and solution of network public opinion governance mechanism under public health emergencies.