English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. China has suffered from increasing levels of ozone pollution inurban areas despite the implementation of various stringent emissionreduction measures since 2013. In this study, we conducted numericalexperiments with an up-to-date regional chemical transport model to assessthe contribution of the changes in meteorological conditions andanthropogenic emissions to the summer ozone level from 2013 to 2017 invarious regions of China. The model can faithfully reproduce the observedmeteorological parameters and air pollutant concentrations and capture theincreasing trend in the surface maximum daily 8 h average (MDA8) ozone(O3) from 2013 to 2017. The emission-control measures implemented bythe government induced a decrease in MDA8 O3 levels in rural areas butan increase in urban areas. The meteorological influence on the ozone trendvaried by region and by year and could be comparable to or even moresignificant than the impact of changes in anthropogenic emissions.Meteorological conditions can modulate the ozone concentration via direct(e.g., increasing reaction rates at higher temperatures) and indirect (e.g.,increasing biogenic emissions at higher temperatures) effects. As anessential source of volatile organic compounds that contributes to ozoneformation, the variation in biogenic emissions during summer varied acrossregions and was mainly affected by temperature. China's midlatitude areas(25 to 40∘ N) experienced a significant decrease inMDA8 O3 due to a decline in biogenic emissions, especially for theYangtze River Delta and Sichuan Basin regions in 2014 and 2015. In contrast,in northern (north of 40∘ N) and southern (south of 25∘ N) China, higher temperatures after 2013 led to an increase in MDA8 O3via an increase in biogenic emissions. We also assessed the individualeffects of changes in temperature, specific humidity, wind field, planetaryboundary layer height, clouds, and precipitation on ozone levels from 2013to 2017. The results show that the wind field change made a significantcontribution to the increase in surface ozone over many parts of China. Thelong-range transport of ozone and its precursors from outside the modelingdomain also contributed to the increase in MDA8 O3 in China, especiallyon the Qinghai–Tibetan Plateau (an increase of 1 to 4 ppbv). Our studyrepresents the most comprehensive and up-to-date analysis of the impact ofchanges in meteorology on ozone across China and highlights the importanceof considering meteorological variations when assessing the effectiveness ofemission control on changes in the ozone levels in recent years.

Worsening urban ozone pollution in China from 2013 to 2017 – Part 1: The complex and varying roles of meteorology