HR: 1340h
AN: AE23A-1003    [Abstracts]
TI: Steady-State Contributions of Mesoscale Convective Systems to the Global Circuit
AU: Davydenko, S S
EM: davyd@appl.sci-nnov.ru
AF: Institute of Applied Physics, Russian Academy of Science, Plasma Physics and High Power Electronics Department, 46 Ulyanov St, Nizhny Novgorod, 603950 Russian Federation
AU: * Stolzenburg, M
EM: mstolzen@olemiss.edu
AF: University of Mississippi, Department of Physics and Astronomy, University, MS 38677 United States
AU: Mareev, E A
EM: mareev@appl.sci-nnov.ru
AF: Institute of Applied Physics, Russian Academy of Science, Plasma Physics and High Power Electronics Department, 46 Ulyanov St, Nizhny Novgorod, 603950 Russian Federation
AU: Marshall, T C
EM: marshall@olemiss.edu
AF: University of Mississippi, Department of Physics and Astronomy, University, MS 38677 United States
AB: Mesoscale convective systems (MCSs) are of interest in the Earth's electric circuit in part because of their great lateral extent, which is an order of magnitude greater than that of an ordinary thunderstorm. The global circuit contribution of one MCS with Type B stratiform region charge structure was modeled by Davydenko et al. [2004]. Using a two-dimensional axisymmetric model and observed electric field profiles in MCS convective and stratiform regions, they found that the MCS current contribution to the global circuit can be two orders of magnitude larger than an ordinary storm's contribution. The modeled Type B stratiform precipitation region dominated the electrical interaction of the MCS with the global electric environment, and its contribution to the global circuit was estimated as about -25 A. This presentation will discuss recent work in modeling the contribution to the global circuit of an MCS with Type A stratiform region charge structure. Although the precipitation structures, microphysics, kinematics, and thermodynamics of Type A and Type B MCSs are generally similar, our investigations show that the current distribution around one Type A MCS is substantially different from the Type B MCS modeled by Davydenko et al. [2004]. For the Type A case, both the stored electrostatic energy and the ohmic-loss power are about 10 times those of the Type B case. The net upward current of the Type A stratiform region is estimated as +32 A. This substantially exceeds the contribution of the convective region and has opposite polarity compared to the Type B structure [Davydenko et al., 2004]. In other words, this MCS serves as a generator in the global circuit. Results from our ongoing, systematic study of thunderstorms as steady-state generators in the global circuit will also be presented. Reference. Davydenko, S. S., E. A. Mareev, T. C. Marshall, and M. Stolzenburg, On the calculation of electric fields and currents of mesoscale convective systems, J. Geophys. Res., 109, D11103, doi:10.1029/2003JD003832, 2004.
DE: 3304 Atmospheric electricity
DE: 3332 Mesospheric dynamics
DE: 3367 Theoretical modeling
SC: Atmospheric and Space Electricity [AE]
MN: Fall Meeting 2005