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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Abstract. This study uses a chemistry–climate model CHASER (MIROC)to explore the roles of heterogeneous reactions (HRs) in global troposphericchemistry. Three distinct HRs of N2O5, HO2, and RO2 areconsidered for surfaces of aerosols and cloud particles. The modelsimulation is verified with EANET and EMEP stationary observations; R/V Mirai ship-based data; ATom1 aircraft measurements; satellite observationsby OMI, ISCCP, and CALIPSO-GOCCP; and reanalysis data JRA55. Theheterogeneous chemistry facilitates improvement of model performance withrespect to observations for NO2, OH, CO, and O3, especially in thelower troposphere. The calculated effects of heterogeneous reactions causemarked changes in global abundances of O3 (−2.96 %), NOx(−2.19 %), CO (+3.28 %), and global mean CH4 lifetime(+5.91 %). These global effects were contributed mostly byN2O5 uptake onto aerosols in the middle troposphere. At thesurface, HO2 uptake gives the largest contributions, with aparticularly significant effect in the North Pacific region (−24 %O3, +68 % NOx, +8 % CO, and −70 % OH), mainlyattributable to its uptake onto clouds. The RO2 reaction has a smallcontribution, but its global mean negative effects on O3 and CO are notnegligible. In general, the uptakes onto ice crystals and cloud dropletsthat occur mainly by HO2 and RO2 radicals cause smaller globaleffects than the aerosol-uptake effects by N2O5 radicals(+1.34 % CH4 lifetime, +1.71 % NOx, −0.56 % O3,+0.63 % CO abundances). Nonlinear responses of tropospheric O3,NOx, and OH to the N2O5 and HO2 uptakes are found in thesame modeling framework of this study (R&gt;0.93). Although all HRsshowed negative tendencies for OH and O3 levels, the effects ofHR(HO2) on the tropospheric abundance of O3 showed a smallincrement with an increasing loss rate. However, this positive tendencyturns to reduction at higher rates (&gt;5 times). Our resultsdemonstrate that the HRs affect not only polluted areas but also remoteareas such as the mid-latitude sea boundary layer and upper troposphere.Furthermore, HR(HO2) can bring challenges to pollution reductionefforts because it causes opposite effects between NOx (increase) andsurface O3 (decrease).

Effects of heterogeneous reactions on tropospheric chemistry: a global simulation with the chemistry–climate model CHASER V4.0