资源环境科技发展态势分析平台

To ensure a good air quality during the 7th Military World Games (MWG) held in the megacity, Wuhan of central China, an unprecedented substantial emission reduction has been conducted during October 13–27, 2019. Here we present an observational overview on the effects of emission control measures as well as their implications by integrated satellite observations and surface measurements. Compared with air quality before control, there is a remarkable overall decline (~15–30%) in PM₁₀ and SO₂ concentration in control period. By contrast, NO_x and O₃ remain at high levels under persistent stagnant weather conditions since vehicle emission is not restricted. Despite high NO_x (~100 μg/m³) in ground measurements, satellite column NO₂ exhibits a considerable decline (~30–50%) over Wuhan, indicating that the large reduction of industrial emission from elevated chimneys has limited effects on changes of NO_x near surface. The NO₃⁻ and NH₄⁺ in PM_2.5 reach peak values at the beginning of emergency control period, and then decrease steadily with a rising temperature. Meanwhile, OC and EC in PM_2.5 have a continuous accumulation process on the premise of enhanced emission control, which can be caused by vehicle emissions. Generally, the stringent emission reduction focusing on industrial sources obviously mitigates particle pollution in Wuhan. Considering complicated relationship between atmospheric pollutants and their precursors, synchronized emission reduction measures based on their accurate roles are necessary in improving air quality effectively.