{"id":22436,"date":"2022-05-21T09:00:20","date_gmt":"2022-05-21T03:15:20","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=22436"},"modified":"2022-05-21T09:00:24","modified_gmt":"2022-05-21T03:15:24","slug":"cloud-discovers-new-way-by-which-aerosols-rapidly-form-and-grow-at-high-altitude","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/cloud-discovers-new-way-by-which-aerosols-rapidly-form-and-grow-at-high-altitude\/","title":{"rendered":"CLOUD discovers new way by which aerosols rapidly form and grow at high altitude"},"content":{"rendered":"\n

Aerosol\u00a0particles can form and grow in Earth\u2019s upper troposphere in an unexpected way, reports the\u00a0CLOUD<\/a>\u00a0collaboration in a\u00a0paper<\/a> published in Nature. <\/p>\n\n\n\n

The new mechanism may represent a major source of cloud and ice seed particles in areas of the upper troposphere where ammonia is efficiently transported vertically, such as over the Asian monsoon regions.<\/p>\n\n\n\n

\"\"
Simulation of aerosol particle formation during the Asian monsoon in a global aerosol model with efficient vertical transport of ammonia into the upper troposphere. Including a mixture of sulfuric acid, nitric acid and ammonia enhance upper-tropospheric particle number concentrations over the Asian monsoon region by a factor of 3\u20135 compared with the same model with only sulfuric acid and ammonia. (Image: CLOUD collaboration, CERN)<\/em><\/figcaption><\/figure>\n\n\n\n

Aerosol particles are known to generally cool the climate by reflecting sunlight back into space and by making clouds more reflective. However, how new aerosol particles form in the atmosphere remains relatively poorly known.<\/p>\n\n\n\n

\u201cNewly formed aerosol particles are ubiquitous throughout the upper troposphere, but the vapours and mechanisms that drive the formation of these particles are not well understood,\u201d explains CLOUD spokesperson Jasper Kirkby. <\/p>\n\n\n\n

\u201cWith experiments performed under cold upper tropospheric conditions in CERN\u2019s CLOUD chamber, we uncovered a new mechanism for extremely rapid particle formation and growth involving novel mixtures of vapours.\u201d<\/p>\n\n\n\n

Using mixtures of sulfuric acid, nitric acid and ammonia vapours in the chamber at atmospheric concentrations, the CLOUD team found that these three compounds form new particles synergistically at rates much faster than those for any combination of two of the compounds. <\/p>\n\n\n\n

The CLOUD researchers found that the three vapours together form new particles 10\u20131000 times faster than a sulfuric acid\u2013ammonia mixture, which, from previous CLOUD measurements, was previously considered to be the dominant source of upper tropospheric particles. Once the three-component particles form, they can grow rapidly from the condensation of nitric acid and ammonia alone to sizes where they seed clouds.<\/p>\n\n\n\n

Moreover, the CLOUD measurements show that these particles are highly efficient at seeding ice crystals, comparable to desert dust particles, which are thought to be the most widespread and effective ice seeds in the atmosphere. When a supercooled cloud droplet freezes, the resulting ice particle will grow at the expense of any unfrozen droplets nearby, so the ice has a major influence on cloud microphysical properties and precipitation.<\/p>\n\n\n\n

The CLOUD researchers went on to feed their measurements into global aerosol models that include the vertical transport of ammonia by deep convective clouds. The models showed that, although the particles form locally in ammonia-rich regions of the upper troposphere such as over the Asian monsoon regions, they travel from Asia to North America in just three days via the subtropical jet stream, potentially influencing Earth\u2019s climate on an intercontinental scale.<\/p>\n\n\n\n

\u201cOur results will improve the reliability of global climate models in accounting for aerosol formation in the upper troposphere and in predicting how the climate will change in the future,\u201d says Kirkby. \u201cOnce again, CLOUD is finding that anthropogenic ammonia has a major influence on atmospheric aerosol particles, and our studies are informing policies for future air pollution regulations.\u201d<\/p>\n\n\n\n

Atmospheric concentrations of sulfuric acid, nitric acid and ammonia were much lower in the pre-industrial era than they are now, and each is likely to follow different concentration trajectories under future air pollution controls. Ammonia in the upper troposphere originates from livestock and fertiliser emissions \u2013 which are unregulated at present \u2013 and is carried aloft in convective cloud droplets, which release their ammonia upon freezing. <\/p>\n","protected":false},"excerpt":{"rendered":"

Aerosol\u00a0particles can form and grow in Earth\u2019s upper troposphere in an unexpected way, reports the\u00a0CLOUD\u00a0collaboration in a\u00a0paper published in Nature. <\/p>\n","protected":false},"author":2,"featured_media":22438,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,121,17],"tags":[],"class_list":["post-22436","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","category-physics","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern-200x200.jpg",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",600,287,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",600,287,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern-550x300.jpg",550,300,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern-95x65.jpg",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",628,300,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",96,46,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2022\/05\/simulation-report-cern.jpg",150,72,false]},"author_info":{"info":["RevoScience"]},"category_info":"News<\/a> Physics<\/a> Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/22436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=22436"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/22436\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/22438"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=22436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=22436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=22436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}