{"359141":{"#nid":"359141","#data":{"type":"news","title":"Man-made pollutants significantly influence how tree emissions form aerosol particles","body":[{"value":"\u003Cp\u003EThe southeastern United States is a natural laboratory for scientists studying how chemicals emitted by human activities and trees interact with each other and affect air quality and climate. A new study has found that certain emissions from cars and coal-fired power plants promote processes that transform naturally occurring emissions from trees into organic aerosols. Organic aerosols make up a substantial fraction of ambient particulate matter (PM) that can affect climate, air quality and human health.\u003C\/p\u003E\u003Cp\u003ECombining laboratory studies and ambient measurements from multiple sites in and around Atlanta, Georgia, and rural Alabama, scientists found that sulfur dioxide and nitrogen oxides directly and substantially mediate the formation of aerosols from the volatile organic compounds produced by trees. \u0026nbsp;\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u201cThis finding is good news for pollution control. If we are able to further reduce sulfur dioxide and nitrogen oxide emissions, we will not only decrease sulfate aerosols but also organic aerosols, thus lowering the total aerosol burden in the southeast United States,\u201d said\u0026nbsp;\u003Ca href=\u0022http:\/\/ng.chbe.gatech.edu\/\u0022\u003ENga Lee (Sally) Ng\u003C\/a\u003E, co-author of the study and assistant professor in Georgia Tech\u2019s School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences. Other Georgia Tech co-authors include professors Rodney Weber and Athanasios Nenes, Georgia Power Scholar and Cullen Peck Faculty Fellow.\u003C\/p\u003E\u003Cp\u003EThe study was sponsored by the National Science Foundation (NSF), the Environmental Protection Agency (EPA), and the National Oceanic and Atmospheric Administration (NOAA). The study was published December 22 in the journal \u003Cem\u003E\u003Ca href=\u0022http:\/\/www.pnas.org\/content\/early\/2014\/12\/17\/1417609112.abstract\u0022\u003EProceedings of the National Academy of Sciences\u003C\/a\u003E.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003EScientists have known for years that human-made pollutants can interact with vegetation-emitted organic compounds, turning them into airborne particles. Those particles may affect air quality, human health and climate. However, to what extent and how exactly human-made pollutants affect aerosol formation from vegetation in the ambient environments are poorly understood.\u003C\/p\u003E\u003Cp\u003EAnthropogenic sulfate, produced mainly by coal-fired power plants, and nitrogen oxides, produced mainly by vehicle emissions, control 43 to 70 percent of the total measured organic aerosol load in the southeastern United States during summer months, the study found.\u003C\/p\u003E\u003Cp\u003EAccording to the study, the formation of aerosols from certain tree emissions is directly controlled by the abundance of sulfate, instead of particle water or particle acidity as suggested by prior studies. This is surprising, but it appears that in the southeastern U.S. the particles have sufficient water and acidity to preclude them from being the controlling factors in aerosol formation. The study further shows that the nighttime aerosol chemistry is more important than previously thought.\u003C\/p\u003E\u003Cp\u003E\u201cAerosol chemistry does not stop at night,\u201d Ng said. After sunset, the nitrogen oxide compounds and ozone can react with the emissions from trees to produce organic aerosols.\u003C\/p\u003E\u003Cp\u003EThe findings may help improve air quality and climate simulations in regions where anthropogenic-biogenic interactions contribute substantially to aerosol formation, Ng said.\u003C\/p\u003E\u003Cp\u003ETo unravel the complexity of what drives particle formation, researchers collected data in ambient field studies using advanced aerosol mass spectrometry techniques, in combination with particle into liquid sampler, and cloud condensation nuclei counter, which quantified the aerosol chemical composition and its ability to uptake liquid water. The data collected, combined with a state-of the art thermodynamic model \u003Ca href=\u0022http:\/\/isorropia.eas.gatech.edu\u0022\u003EISORROPIA\u003C\/a\u003E, revealed the contribution of organic species and sulfate to the acidity and water uptake. A comprehensive multivariate linear regression analysis showed that sulfate alone, not its associated water uptake or acidity, was responsible for the organic aerosol levels measured. \u0026nbsp;This study also used the \u003Ca href=\u0022http:\/\/www.coe.gatech.edu\/news\/air-we-breathe\u0022\u003EGeorgia Tech Environmental Chamber Facility\u003C\/a\u003E to investigate aerosol formation and chemical composition under nighttime conditions in a well-controlled laboratory setting, which was supported by an \u003Ca href=\u0022http:\/\/www.coe.gatech.edu\/news\/chbes-nga-lee-sally-ng-receives-epa-star-early-career-award\u0022\u003EEPA Early Career Award Ng received\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003EThe study is an outcome of one of the largest U.S. atmospheric chemistry field projects in decades \u2013 the \u003Ca href=\u0022http:\/\/www.news.gatech.edu\/features\/middle-nowhere-surrounded-everything\u0022\u003ESoutheast Atmosphere Study (SAS)\u003C\/a\u003E, which took place in Alabama\u2019s Talladega National Forest in 2013. The initiative brought together dozens of national and international institutions. The research teams used instrumentation onboard aircraft and ground sites to learn more about the region\u2019s atmospheric chemistry. Data was also collected from four sites around the Atlanta area over two years, as part of the U.S. Environmental Protection Agency (EPA) Clean Air Research Center at Georgia.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u201cTo study this type of chemistry and understand how man-made pollutants interact with natural emissions, the southeast United States is the best place in the country,\u201d Ng said.\u003C\/p\u003E\u003Cp\u003E\u201cWe have seen evidence for this possible effect in prior studies a number of years ago. Results from this study provides a coherent understanding of this interaction and allow us to put together a comprehensive picture,\u201d Weber added.\u003C\/p\u003E\u003Cp\u003EGeorgia Tech is developing a reputation as a hub of clean air research and is home to the \u003Ca href=\u0022http:\/\/scape.gatech.edu\/\u0022\u003ESoutheastern Center for Air Pollution and Epidemiology (SCAPE)\u003C\/a\u003E, a collaborative effort with Emory University that has received $8 million in funding for five years. Ng, Nenes, Weber and other researchers at Georgia Tech were recently awarded a \u003Ca href=\u0022http:\/\/www.news.gatech.edu\/2014\/09\/25\/new-technology-tracks-tiniest-pollutants-real-time\u0022\u003EMajor Research Instrumentation (MRI) Program grant\u003C\/a\u003E from the National Science Foundation (NSF), totaling approximately $700,000, to purchase a state-of-art, gas-particle high resolution mass spectrometer that can identify the components of gases and aerosol particles in real time.\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis research is supported by the National Science Foundation under award number 1242258, the US Environmental Protection Agency (EPA) under awards RD-83540301 and R835410, and the National Oceanic and Atmospheric Administration under award NA10OAR4310102. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Lu Xu, et al. \u0022Effects of anthropogenic emissions on aerosol formation from isoprene and monoterpenes in the southeastern United States.\u0022 (PNAS, December 2014) DOI: 10.1073\/pnas.1417609112\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News\u003Cbr \/\u003E Georgia Institute of Technology\u003Cbr \/\u003E 177 North Avenue\u003Cbr \/\u003E Atlanta, Georgia\u0026nbsp; 30332-0181\u0026nbsp; USA\u003Cbr \/\u003E \u003C\/strong\u003E\u003Ca href=\u0022https:\/\/twitter.com\/GTResearchNews\u0022\u003E\u003Cstrong\u003E@GTResearchNews\u003C\/strong\u003E\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: Brett Israel (\u003Ca href=\u0022https:\/\/twitter.com\/btiatl\u0022\u003E@btiatl\u003C\/a\u003E) (404-385-1933) (\u003Ca href=\u0022mailto:brett.israel@comm.gatech.edu\u0022\u003Ebrett.israel@comm.gatech.edu\u003C\/a\u003E) or John Toon (404-894-6986) (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E)\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: Brett Israel\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"A new study has found that certain emissions from cars and coal-fired power plants promote processes that transform naturally occurring emissions from trees into organic aerosols."}],"uid":"27902","created_gmt":"2014-12-24 10:25:55","changed_gmt":"2016-10-08 03:17:46","author":"Brett Israel","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2014-12-24T00:00:00-05:00","iso_date":"2014-12-24T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"359171":{"id":"359171","type":"image","title":"Yorkville monitoring site","body":null,"created":"1449245775","gmt_created":"2015-12-04 16:16:15","changed":"1475895096","gmt_changed":"2016-10-08 02:51:36","alt":"Yorkville monitoring site","file":{"fid":"202074","name":"scape_yorkville.jpg","image_path":"\/sites\/default\/files\/images\/scape_yorkville.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/scape_yorkville.jpg","mime":"image\/jpeg","size":1942745,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/scape_yorkville.jpg?itok=oRqQUQL_"}},"328691":{"id":"328691","type":"image","title":"Sally Ng","body":null,"created":"1449245064","gmt_created":"2015-12-04 16:04:24","changed":"1475895039","gmt_changed":"2016-10-08 02:50:39","alt":"Sally Ng","file":{"fid":"201823","name":"sally-ng-research-chamber.jpg","image_path":"\/sites\/default\/files\/images\/sally-ng-research-chamber.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/sally-ng-research-chamber.jpg","mime":"image\/jpeg","size":7552295,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/sally-ng-research-chamber.jpg?itok=uWnx_NMk"}}},"media_ids":["359171","328691"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"144","name":"Energy"},{"id":"154","name":"Environment"}],"keywords":[{"id":"113111","name":"aerosols"},{"id":"489","name":"atlanta"},{"id":"1963","name":"particles"},{"id":"169677","name":"sally ng"},{"id":"167302","name":"southeast"}],"core_research_areas":[{"id":"39531","name":"Energy and Sustainable Infrastructure"}],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EBrett Israel\u003C\/p\u003E\u003Cp\u003E404-385-1933\u003C\/p\u003E\u003Cp\u003E@btiatl\u003C\/p\u003E","format":"limited_html"}],"email":["brett.israel@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}