{"70991":{"#nid":"70991","#data":{"type":"news","title":"Severe Storms Research Center Boosts Defenses Against Twisters","body":[{"value":"\u003Cp\u003EThe tornado that ripped through downtown Atlanta on March 14, 2008, produced a death, psychological shock and some $150 million in damage. Yet it was hardly an isolated event. \n\u003C\/p\u003E\n\u003Cp\u003EGeorgia ranks high among tornado-plagued areas of the United States. It was 18th among the most affected states between 1953 and 2004. And in 2007, Georgia experienced 42 twisters; only seven states suffered more hits.\n\u003C\/p\u003E\n\u003Cp\u003EHelping to protect Georgia residents against such violent weather is the job of the researchers of the Severe Storms Research Center (SSRC) at the Georgia Tech Research Institute (GTRI). One of their tasks: to explore and develop new technologies able to improve both the accuracy and the timeliness of tornado warnings. \n\u003C\/p\u003E\n\u003Cp\u003ECurrently, NEXRAD Doppler radar technology is state-of-the-art in the U.S., which is ravaged by more tornadoes than anyplace else on Earth. NEXRAD offers about a 15-minute average advance warning that a tornado may hit. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022That\u0027s a big improvement over the old days, when a funnel cloud on the horizon was often the first warning,\u0022 said John Trostel, deputy director of the SSRC. \u0022Before NEXRAD was established in the 1990s, you would have been lucky to have gotten a 30-second warning.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EThe GTRI center was founded after a tornado struck Gainesville, Ga., with no warning in March 1998, leaving 11 people dead in Hall County, recalls SSRC Director Gene Greneker. A task force formed by then-Georgia Gov. Zell Miller recommended a severe-storms center with several missions, including conducting cutting-edge research, collecting and archiving storm data and improving detection and warning. The center was initially funded through the Federal Emergency Management Agency (FEMA), and on-going support has come through the state of Georgia with the continuing involvement of the Georgia Emergency Management Agency (GEMA). \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Part of our goal is to explore what\u0027s different about the severe storms of north Georgia,\u0022 Greneker said. \u0022Tornadoes in Georgia are often short-lived events that take place over a few minutes, while those in Kansas or Oklahoma may last for an hour.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003ENEXRAD continues to be the first line of tornado defense, Greneker explains. Earlier weather radars dating back to the 1950s could sometimes reveal the classic \u0022hook\u0022 echo on some tornadoes, but NEXRAD is far more effective. \n\u003C\/p\u003E\n\u003Cp\u003EToday\u0027s national network of NEXRAD stations uses three-dimensional Doppler technology to detect wind direction and other factors; the information shows up on-screen in brightly colored cells that resemble the pixels of a heavily magnified digital photo. When winds in a given area begin to twist in opposite directions - a tornadic phenomenon called wind shear - two cells form a distinctive on-screen \u0022couplet\u0022 that alerts weather watchers a tornado may be forming. \n\u003C\/p\u003E\n\u003Cp\u003ESSRC uses several tools to amass and study NEXRAD data, including GR2Analyst software, developed in Georgia, and a WDSS-II analysis station. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022I\u0027m seeing very interesting trends in the number of tornadoes that occur annually in Georgia,\u0022 Trostel said. \u0022There was an average of about 15 to 25 events from 1950 through 1970, then a peak in the early 1970s to over 40 events, and then a return to 15 to 25. But since 2000, the trend in the number of annual events appears to be again increasing.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ENew Insights into Tornadoes \u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003ENEXRAD is an important tool, Trostel acknowledges. Yet to increase the weather watcher\u0027s arsenal, and potentially improve warning times and accuracy, GTRI researchers are developing additional approaches to tornado detection and monitoring. \n\u003C\/p\u003E\n\u003Cp\u003ECurrently, SSRC studies North Georgia weather using 12 research systems that use a wide variety of instruments, sensors, computers and software, with two more systems under development. Researchers involved in the effort include Greneker, Trostel, Ed Reedy, Tom Perry and Jenny Matthews, as well as a number of students. \n\u003C\/p\u003E\n\u003Cp\u003EAmong the SSRC\u0027s top areas of study is the complex role that lightning and acoustics play in North Georgia\u0027s severe storms and in the formation of tornadoes. \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ELightning\u003C\/strong\u003E - Researchers based at GTRI\u0027s Cobb County Research Facility are pursuing several approaches that could potentially correlate lightning\u0027s behavior with tornado activity: \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003ELightning mapping arrays \u003C\/em\u003Euse multiple receiving stations to monitor severe storms as they move through an area. The SSRC and other Atlanta-area weather stations - such as the National Weather Service at Peachtree City - are developing a six-station array that will augment data already coming from an existing array in northern Alabama; \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003EElectric field mills \u003C\/em\u003Emeasure the enormous changes in electric fields between fair weather and severe storms, providing important data that can even correlate raindrop size and frequency with other storm parameters; \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003EA lighting polarization ratio station \u003C\/em\u003Emonitors the horizontally and vertically polarized radio-frequency signals created by lightning strokes, providing data on the behavior of cloud- to-cloud and cloud-to-ground lightning. Greater understanding of lightning, especially the less-understood cloud-to-cloud variety, could shed light on tornado formation; \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003EGamma-ray detectors \u003C\/em\u003Erecord the gamma- and X-rays that emanate from lightning strokes, and offer the potential to correlate the appearance of these powerful phenomena with tornado activity. \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EAcoustic signals \u003C\/strong\u003E- Severe storms emit very low-frequency sounds -- in the range of 50 hertz and below, which is analogous to the sonic footprint of an earthquake. Tornado vortices appear to emit these \u0022infra-sounds\u0022 in frequencies ranging from 1 hertz down to tenths of a hertz. At the Cobb Country Research Facility, GTRI researchers are building an array of low-frequency sensors that may allow them to identify sonic signatures unique to tornadoes. \n\u003C\/p\u003E\n\u003Cp\u003ETrostel notes that there are myriad ways to study severe storms, many of them surprisingly cost-efficient. He points to a field mill developed by a local high-school student; constructed from such materials as a coffee can, it can detect electrical fields associated with storms. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022This device does a very good job, and it cost $87,\u0022 Trostel said. \u0022We want to get Georgia high-school science classes to construct and deploy these detectors - and then we could track storm-related electrical fields as they progress across the state.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003E\u003Cstrong\u003EThis article was originally published in the Summer 2008 issue of Georgia Tech\u0027s Research Horizons magazine.\u003C\/strong\u003E\u003C\/em\u003E\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 (404-894-6986); E-mail: (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E); Kirk Englehardt (404-407-7280); E-mail: (\u003Ca href=\u0022mailto:kirkeng@gatech.edu\u0022\u003Ekirkeng@gatech.edu\u003C\/a\u003E) or Abby Vogel (404-385-33640; E-mail: (\u003Ca href=\u0022mailto:avogel@gatech.edu\u0022\u003Eavogel@gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ETechnical Contact\u003C\/strong\u003E: John Trostel (404-407-7690); E-mail: (\u003Ca href=\u0022mailto:john.trostel@gtri.gatech.edu\u0022\u003Ejohn.trostel@gtri.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: Rick Robinson\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Center\u0027s mission is to protect Georgia citizens"}],"field_summary":[{"value":"The Severe Storms Research Center explores and develops new technologies for improving the accuracy and timeliness of tornado warnings.  Part of the Georgia Tech Research Institute (GTRI), the Center is studying the complex role that lightning and acoustics play in severe storms.","format":"limited_html"}],"field_summary_sentence":[{"value":"Research center aims to protect Georgians against tornadoes"}],"uid":"27303","created_gmt":"2008-09-25 00:00:00","changed_gmt":"2016-10-08 03:03:19","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2008-09-25T00:00:00-04:00","iso_date":"2008-09-25T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"70992":{"id":"70992","type":"image","title":"Sferic antenna","body":null,"created":"1449177338","gmt_created":"2015-12-03 21:15:38","changed":"1475894625","gmt_changed":"2016-10-08 02:43:45"},"70993":{"id":"70993","type":"image","title":"Electric field mill","body":null,"created":"1449177338","gmt_created":"2015-12-03 21:15:38","changed":"1475894625","gmt_changed":"2016-10-08 02:43:45"},"70994":{"id":"70994","type":"image","title":"Radar screen","body":null,"created":"1449177338","gmt_created":"2015-12-03 21:15:38","changed":"1475894625","gmt_changed":"2016-10-08 02:43:45"}},"media_ids":["70992","70993","70994"],"related_links":[{"url":"http:\/\/www.gtri.gatech.edu\/centers\/ssrc","title":"Severe Storms Research Center"},{"url":"http:\/\/www.gtri.gatech.edu\/","title":"Georgia Tech Research Institute"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"145","name":"Engineering"},{"id":"154","name":"Environment"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"1501","name":"acoustic"},{"id":"1396","name":"lightning"},{"id":"170862","name":"storm"},{"id":"1233","name":"tornado"},{"id":"2027","name":"warning"}],"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":""}}}