author = "Schumann, Carina and Saba, Marcelo Magalh{\~a}es Fares and 
                         Warner, Tom A. and Ferro, Marco A. S. and Helsdon Junior, John H. 
                         and Thomas, Ron and Orville, Richard E.",
          affiliation = "{University of the Witwatersrand Johannesburg} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {South Dakota School 
                         of Mines and Technology} and {Instituto de Aeron{\'u}atica e 
                         Espa{\c{c}}o (IAE)} and {South Dakota School of Mines and 
                         Technology} and {New Mexico Tech} and {Texas A\&M University}",
                title = "On the triggering mechanisms of upward lightning",
              journal = "Scientific Reports",
                 year = "2019",
               volume = "9",
                pages = "e9576",
                month = "July",
             abstract = "Upward lightning studies took place in Rapid City, South Dakota, 
                         USA and S. Paulo, Brazil during the summer thunderstorm seasons 
                         from 2011 to 2016. One of the main objectives of these campaigns 
                         was to evaluate and characterize the triggering of upward positive 
                         leaders from tall objects due to preceding nearby flash activity. 
                         110 upward flashes were observed with a combination of high-and 
                         standard-speed video and digital still cameras, electric field 
                         meters, fast electric-field antenna systems, and for two seasons, 
                         a Lightning Mapping Array. These data were analyzed, along with 
                         correlated lightning location system data, to determine the 
                         triggering flash type responsible for the initiation of upward 
                         leaders from towers. In this paper, we describe the various 
                         processes during flash activity that can trigger upward leaders 
                         from tall objects in the USA and in Brazil. We conclude that the 
                         most effective triggering component is the propagation of the 
                         in-cloud negative leader during the continuing current that 
                         follows a positive return stroke.",
                  doi = "10.1038/s41598-019-46122-x",
                  url = "http://dx.doi.org/10.1038/s41598-019-46122-x",
                 issn = "2045-2322",
             language = "en",
           targetfile = "2019 B - Nature Scientific Reports Upward Triggering Mechanisms 
                         Schumann et al.pdf",
        urlaccessdate = "21 jan. 2021"