{"72547":{"#nid":"72547","#data":{"type":"news","title":"Ocean Creatures Linked to Cloud Cover Increases","body":[{"value":"\u003Cp\u003EAtmospheric scientists have reported a new and potentially important mechanism by which chemical emissions from ocean phytoplankton may influence the formation of clouds that reflect sunlight away from our planet.  \u003C\/p\u003E\n\u003Cp\u003EDiscovery of the new link between clouds and the biosphere grew out of efforts to explain increased cloud cover observed over an area of the Southern Ocean where a large bloom of phytoplankton was occurring.  Based on satellite data, the researchers hypothesized that airborne particles produced by oxidation of the chemical isoprene - which is emitted by the phytoplankton - may have contributed to a doubling of cloud droplet concentrations seen over a large area of ocean off the eastern coast of South America.  \n\u003C\/p\u003E\n\u003Cp\u003EUsing complex numerical models, they estimated that the resulting increase in cloudiness reduced the absorption of sunlight by an amount comparable to what has been measured in highly polluted areas of the globe.  If confirmed by field studies, this connection between clouds and biological activity could add a critical new component to global climate models.  Many environmental scientists believe that increased cloud cover may be partially countering the effects of global warming by reducing the amount of energy the planet absorbs from the sun.\n\u003C\/p\u003E\n\u003Cp\u003EResearchers Athanasios Nenes of the Georgia Institute of Technology and Nicholas Meskhidze - formerly at Georgia Tech but now at North Carolina State University - reported their findings Nov. 2 in Science Express, the online advance publication of the journal \u003Cem\u003EScience\u003C\/em\u003E.  The research was sponsored by NASA, the National Science Foundation and a Blanchard-Milliken Young Faculty Fellowship.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022Studies like this one may help reshape the way we think about how the biosphere interacts with clouds and climate,\u0022 said Nenes, an assistant professor in Georgia Tech\u0027s School of Earth and Atmospheric Sciences and School of Chemical and Biomolecular Engineering.  \u0022One of the largest uncertainties right now in climate models is the ability to predict how clouds would respond to changing particle levels - whether they originate from humans with air pollution or from biological activity.  We can now see very strongly the influence of marine biology on oceanic clouds.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EResearchers had previously theorized that dimethyl sulfide (DMS) - which is also emitted by phytoplankton - affects the formation of clouds by increasing the number of sulfate particles, which can absorb moisture and form cloud droplets.  When oxidized, isoprene may enhance the effect of DMS by increasing the number and size of the particles while helping them to chemically attract more moisture.  The impact of isoprene on atmospheric particulate matter was previously thought to be important only for terrestrial plants, Nenes said.\n\u003C\/p\u003E\n\u003Cp\u003EThe researchers stumbled upon the phytoplankton-cloud connection quite accidentally.  \u0022While looking at the satellite pictures, I noticed that cloud properties over large phytoplankton blooms were significantly different from those that occurred away from the blooms,\u0022 recalled Meskhidze, now an assistant professor in NC State\u0027s College of Physical and Mathematical Sciences.\n\u003C\/p\u003E\n\u003Cp\u003EThe Southern Ocean normally has relatively few particles around which cloud droplets can form.  The isoprene mechanism could therefore have a significant effect on the development of clouds there - and may account for most of variation in the area\u0027s cloud cover.  \n\u003C\/p\u003E\n\u003Cp\u003E\u0022If a lot of particles form because of isoprene oxidation, you suddenly have a lot more droplets in clouds, which tends to make them brighter,\u0022 Nenes explained.  \u0022In addition to becoming brighter, the clouds can also have less frequent precipitation, so you might have a build-up of clouds.  Overall, this makes the atmosphere cloudier and reflects more sunlight back into space.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EIn their paper, the researchers estimated that the isoprene emissions reduced energy absorption in the area by about 15 watts per square meter.  \u0022This is a huge signal,\u0022 said Nenes.  \u0022You would normally expect to see a change of a couple of watts.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EThe Southern Ocean is ideal for study because it is largely untouched by pollution and has relatively steady temperature and meteorological conditions during the seasons in which phytoplankton blooms appear.  \u0022This seems to be one of those rare regions in the globe where the biology really takes over,\u0022 Nenes explained.  \u0022That allows us to see strongly the impact of biology on the clouds.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EAs a next step, Nenes would like to examine other areas of the globe for similar activity.  \u0022There are a lot of areas that have intense biological activity, so with time we are going to explore more regions to see if this is a widespread phenomenon.  Chances are that we will see this in other places,\u0022 he added.\n\u003C\/p\u003E\n\u003Cp\u003ENenes and Meskhidze used data from satellite observations to estimate the amount of chlorophyll in the ocean, the emission of isoprene and its connection to cloud formation.  Before this new mechanism can be incorporated into global climate models, however, it will have to be confirmed by field experiments.\n\u003C\/p\u003E\n\u003Cp\u003EAtmospheric scientists believe that by blocking sunlight, increased cloudiness has up until now partially mitigated the effects of global warming. The role of oceanic biology on cloud formation could therefore be a major factor in controlling global climate, and the new mechanism identified by Nenes and Meskhidze may make it even more important. This effect needs to be better understood, Nenes noted, because anything that can change global clouds can dramatically alter the impact of greenhouse gases on our changing climate. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022It shows that there is still a lot we need to explore to better understand the delicate balance in nature,\u0022 said Meskhidze.  \u0022It will require the cooperative efforts of researchers from many different fields to identify the chemical components in these aerosols, to estimate the amounts of this and other potentially important gases emitted from the ocean, and to better characterize the effort of organics on cloud droplet formation.\u0022\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 100\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon, Georgia Tech (404-894-6986); E-mail: (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Jane Sanders, Georgia Tech (404-894-2214); E-mail: (\u003Ca href=\u0022mailto:jsanders@gatech.edu\u0022\u003Ejsanders@gatech.edu\u003C\/a\u003E) or Tracey Peake, NC State (919-515-6142); E-mail: (\u003Ca href=\u0022mailto:tracey_peake@ncsu.edu\u0022\u003Etracey_peake@ncsu.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ETechnical Contacts\u003C\/strong\u003E: Athanasios Nenes, Georgia Tech (404-894-9225); E-mail: (\u003Ca href=\u0022mailto:nenes@eas.gatech.edu\u0022\u003Enenes@eas.gatech.edu\u003C\/a\u003E) or Nicholas Meskhidze, NC State (919-515-7243); E-mail: (\u003Ca href=\u0022mailto:nmeskhi@ncsu.edu\u0022\u003Enmeskhi@ncsu.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\n\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Chemical emissions from phytoplankton may influence cloudiness"}],"field_summary":[{"value":"Atmospheric scientists have reported a new and potentially important mechanism by which chemical emissions from ocean phytoplankton may influence the formation of clouds that reflect sunlight away from our planet.","format":"limited_html"}],"field_summary_sentence":[{"value":"Ocean cloud cover may be linked to phytoplankton"}],"uid":"27303","created_gmt":"2006-11-07 01:00:00","changed_gmt":"2016-10-08 03:03:29","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2006-11-07T00:00:00-05:00","iso_date":"2006-11-07T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"72548":{"id":"72548","type":"image","title":"Phytoplankton bloom","body":null,"created":"1449177934","gmt_created":"2015-12-03 21:25:34","changed":"1475894658","gmt_changed":"2016-10-08 02:44:18"},"72549":{"id":"72549","type":"image","title":"Cloud droplet concentration","body":null,"created":"1449177934","gmt_created":"2015-12-03 21:25:34","changed":"1475894658","gmt_changed":"2016-10-08 02:44:18"}},"media_ids":["72548","72549"],"related_links":[{"url":"http:\/\/www.chbe.gatech.edu\/","title":"School of Chemical \u0026 Biomolecular Engineering"},{"url":"http:\/\/www.eas.gatech.edu\/","title":"School of Earth and Atmospheric Sciences"},{"url":"http:\/\/www.eas.gatech.edu\/people\/faculty\/nenes.htm","title":"Athanasios Nenes"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"154","name":"Environment"},{"id":"146","name":"Life Sciences and Biology"},{"id":"135","name":"Research"}],"keywords":[{"id":"2262","name":"climate"},{"id":"7598","name":"clouds"},{"id":"7597","name":"photoplankton"},{"id":"170892","name":"sunlight"},{"id":"2327","name":"warming"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}