Following on a successful two-year multi-investigator field data collection campaign, this research effort will focus on identification of physical processes and interactions pivotal to the genesis, maintenance, and demise of tornadoes developing within broader rotational flows ("mesocyclones") that characterize supercell thunderstorms. The need for improved understanding and development of more reliable means to identify and provide advance warning of tornado formation are key objectives of the joint NSF-NOAA sponsored VORTEX2 (Verification of the Origins of Rotation in Tornadoes) project, which encompassed multi-platform field activities providing a wealth of radar and in-situ thermodynamic data within severe thunderstorms, tornadoes, and their supporting environments. The intellectual merit of this effort will rest upon this research team's specific plans to exploit these data in their study of controls on tornado genesis, maintenance and demise, as well as the potential role of storm mergers in influencing these processes. Model-based data analysis and assimilation will be conducted in tandem with more idealized numerical simulation approaches. The specific research objectives to be addressed during this project are to: (1) Determine the relative roles of environmental versus storm-generated vorticity in the genesis and evolution of tornadoes (2) investigate the roles of the rear- and forward-flank downdrafts in the genesis and evolution of tornadoes, (3) examine the origin and characteristics of secondary rear-flank gust fronts and their possible role in the genesis and evolution of tornadoes, (4) explore how tornadoes are influenced by changes in the thermodynamic properties and circulation of their mesocyclone-scale surroundings, and by changes in the strength or location of the overlying parent thunderstorm updraft, and (5) to investigate the dynamics of storm interactions and cell mergers and the ways in which they can influence the development of vorticity in the storms.
Broader impacts of this effort will hinge upon transfer of physical understanding and potential analysis techniques to operational meteorologists in order that they may ultimately provide more precise tornado warnings and decreased false alarm rates, as well as in providing the opportunity for training of students and early-career scientists including individuals drawn from underrepresented groups in the atmospheric sciences.
