{"id":2305,"date":"2023-10-02T16:16:02","date_gmt":"2023-10-02T14:16:02","guid":{"rendered":"https:\/\/urbag.eu\/?p=2305"},"modified":"2023-10-02T16:16:02","modified_gmt":"2023-10-02T14:16:02","slug":"new-publication-in-atmospheric-chemistry-physics","status":"publish","type":"post","link":"https:\/\/webs.uab.cat\/atmosphere\/2023\/10\/02\/new-publication-in-atmospheric-chemistry-physics\/","title":{"rendered":"New publication in “Atmospheric, Chemistry and Physics”"},"content":{"rendered":"

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See full article\/ Veure l’article complet<\/strong><\/a><\/p>\n

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English:<\/strong><\/p>\n

Tropospheric ozone (O3) is an important surface pollutant in urban areas, and it has complex formation mechanisms that depend on the atmospheric chemistry and on meteorological factors. The severe reductions observed in anthropogenic emissions during the COVID-19 pandemic can further our understanding of the photochemical mechanisms leading to O3 formation and provide guidance for policies aimed at reducing air pollution. In this study, we use the Weather Research and Forecasting model with Chemistry (WRF-Chem) coupled with the urban canopy building effect parameterization and building energy model (BEP\u2009+\u2009BEM) to investigate changes in the ozone chemistry over the metropolitan area of Barcelona (AMB) and its atmospheric plume moving northwards, which is responsible for the highest number of hourly O3 exceedances in Spain. The trajectories of the air masses from the AMB to the Pyrenees are studied with the Lagrangian FLEXible PARTicle dispersion model with WRF (FLEXPART-WRF). The aim is to investigate the response of ozone chemistry to reduction in precursor emissions (NOx \u2013 nitrogen oxides; VOCs \u2013 volatile organic compounds). The results show that, with the reduction in emissions, (1) the ozone chemistry tends to enter the NOx-limited or transition regimes, but highly polluted urban areas are still in the VOC-limited regime; (2) the reduced O3 production is overwhelmed by reduced nitric oxide (NO) titration, resulting in a net increase in the O3 concentration (up to 20\u2009%) in the evening; (3) the increase in the maximum O3 level (up to 6\u2009%) during the highest emission-reduction period could be attributed to an enhancement in the atmospheric oxidants hydroxyl and nitrate radical (OH and NO3) given their strong link with O3 loss or production chemistry; (4) the daily maximum levels of ozone and odd oxygen species (Ox) generally decreased (4\u2009%) in May \u2013 a period with intense radiation which favours ozone production \u2013 with the reduced atmospheric OH and NO3 oxidants, indicating an improvement in the air quality; and (5) ozone precursor concentration changes in the urban plume of Barcelona contribute significantly to the level of pollution along the 150\u2009km south-to-north valley in the Pyrenees. Our results indicate that O3 abatement strategies cannot rely only on NOx emission control but must include a significant reduction in anthropogenic sources of VOCs. In addition, our results show that mitigation strategies intended to reduce O3 should be designed according to the local meteorology, air transport, particular ozone regimes, and oxidation capacity of the atmosphere of the urban area.<\/p>\n

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Catal\u00e0:<\/strong><\/p>\n

L’oz\u00f3 troposf\u00e8ric (O3) \u00e9s un important contaminant de superf\u00edcie en zones urbanes, i els seus mecanismes de formaci\u00f3 s\u00f3n complexos i depenen de la qu\u00edmica atmosf\u00e8rica i de factors meteorol\u00f2gics. Les importants reduccions observades en les emissions antropog\u00e8niques durant la pand\u00e8mia de COVID-19 poden ajudar-nos a comprendre millor els mecanismes fotoqu\u00edmics que condueixen a la formaci\u00f3 d’O3 i orientar les pol\u00edtiques destinades a reduir la contaminaci\u00f3 atmosf\u00e8rica. En aquest estudi, utilitzem el model Weather Research and Forecasting with Chemistry (WRF-Chem) acoblat amb les parametritzacions “urban canopy building effect parameterization and building energy model”\u00a0 (BEP + BEM) per investigar els canvis en la qu\u00edmica de l’oz\u00f3 sobre l’\u00e0rea metropolitana de Barcelona (AMB) i el seu despla\u00e7ament cap al nord, responsable del major nombre de superacions hor\u00e0ries d’ O3 a Espanya. Les traject\u00f2ries de les masses d’aire des de l’AMB fins als Pirineus s’estudien amb el model de dispersi\u00f3 lagrangi\u00e0 FLEXible PARTicle amb WRF (FLEXPART-WRF). L’objectiu \u00e9s investigar la resposta de la qu\u00edmica de l’oz\u00f3 a la reducci\u00f3 de les emissions de precursors (NOx: \u00f2xids de nitrogen; VOC: compostos org\u00e0nics vol\u00e0tils). Els resultats mostren que, amb la reducci\u00f3 de les emissions, (1) la qu\u00edmica de l’oz\u00f3 tendeix a entrar en els r\u00e8gims limitats per NOx o de transici\u00f3, per\u00f2 les zones urbanes molt contaminades segueixen en el r\u00e8gim limitat per VOC, (2) la menor producci\u00f3 d’O3 es veu superada per la reducci\u00f3 d’\u00f2xid n\u00edtric (NO), la qual cosa dona lloc a un augment net de la concentraci\u00f3 d’O3 (fins a un 20%) a la tarda; (3) l’augment del nivell m\u00e0xim d’O3 (fins a un 6 %) durant el per\u00edode de major reducci\u00f3 d’emissions podria atribuir-se a un augment dels oxidants atmosf\u00e8rics radicals hidroxil i nitrat (OH i NO3), donada la seva estreta relaci\u00f3 amb la qu\u00edmica de p\u00e8rdua o producci\u00f3 d’O3; (4) els nivells m\u00e0xims diaris d’oz\u00f3 i d’Ox van disminuir en general (4 %) al maig -per\u00edode d’intensa radiaci\u00f3 que afavoreix la producci\u00f3 d’oz\u00f3- amb la reducci\u00f3 dels oxidants atmosf\u00e8rics OH i NO3, la qual cosa indica una millora de la qualitat de l’aire; i (5) els canvis de concentraci\u00f3 de precursors d’oz\u00f3 en el plomall urb\u00e0 de Barcelona contribueixen significativament al nivell de contaminaci\u00f3 al llarg dels 150 km de la vall sud-nord dels Pirineus. Els nostres resultats indiquen que les estrat\u00e8gies de reducci\u00f3 de l’O3 no poden basar-se \u00fanicament en el control de les emissions de NOx, sin\u00f3 que han d’incloure una reducci\u00f3 significativa de les fonts antropog\u00e8niques de VOC. A m\u00e9s, els nostres resultats mostren que les estrat\u00e8gies de mitigaci\u00f3 destinades a reduir l’ O3 s’ han de dissenyar en funci\u00f3 de la meteorologia local, el transport aeri, els r\u00e8gims particulars d’ oz\u00f3 i la capacitat d’ oxidaci\u00f3 de l’ atmosfera de la zona urbana.<\/p>\n

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Image<\/strong> extracted from the article demonstrating the impact of the pre-COVID, lockdown, and normalization periods on transportation modes and emissions of air pollutants and suspended particles. \/ Imatge<\/strong> extreta de l’article en la qual es mostren els efectes de l’etapa pre-covid, confinament i normalitzaci\u00f3 en els principals mitjans de transport i les emissions de gasos contaminants i part\u00edcules.<\/em><\/p>\n

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Title: Modelling the impacts of emission changes on O3 sensitivity, atmospheric oxidation capacity, and pollution transport over the Catalonia region \/<\/p>\n

Tropospheric ozone (O3) is an important surface pollutant in urban areas, and it has complex formation mechanisms that depend on the atmospheric chemistry and on meteorological factors. The severe reductions observed in anthropogenic emissions during the COVID-19 pandemic can further our understanding of the photochemical mechanisms leading to O3 formation.<\/p>\n","protected":false},"author":3153,"featured_media":2317,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[249,7,229,16,56,8,146,208,233,250,10,103,62,169],"class_list":["post-2305","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general","tag-air-pollution","tag-amb","tag-article","tag-barcelona","tag-bepbem","tag-covid-19","tag-o3","tag-ozone","tag-paper","tag-pollution","tag-urbag","tag-urban","tag-wrf","tag-wrf-chem"],"_links":{"self":[{"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/posts\/2305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/users\/3153"}],"replies":[{"embeddable":true,"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/comments?post=2305"}],"version-history":[{"count":0,"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/posts\/2305\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/media\/2317"}],"wp:attachment":[{"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/media?parent=2305"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/categories?post=2305"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/webs.uab.cat\/atmosphere\/wp-json\/wp\/v2\/tags?post=2305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}