Electrical structure in thunderstorm convective regions: 3. Synthesis

Abstract

Abstract. In this paper, results from nearly 50 electric field soundings through convective regions of mesoscale convective systems (MCSs), isolated supercelIs, and isolated New Mexican mountain storms are compared and synthesized. These three types of thunderstorm convection are found to have a common, basic electrical structure. Within convective updrafts the basic charge structure has four charge regions, alternating in polarity, and the lowest is positive. Outside updrafts of convection there are typically at least six charge regions, alternating in polarity, and the lowest is again positive. Among the three storm types, there are differences in the heights and temperatures at which the basic four charge regions are found in updrafts. The height (temperature) of the center of the main negative charge region averages 6.93 km (-16øC) in MCS convective region updrafts, 9.12 km (-22øC) in supercell updrafts, and 6.05 km (-7øC) in New Mexican mountain storm updrafts. In updraft soundings through all three storm types, the center height of the main negative charge region increases with increasing average balloon ascent rate and updraft speed at a rate of about 0.3 km per 1 rn s -1, with a correlation coefficient of 0.94.A schematic illustrates the basic four-and six-charge structure for thunderstorm convective regions, and it is offered as an improved model for thunderstorm charge structure.

A Thermodynamic, kinematic and microphysical analysis of a jet and gigantic jet‐producing Florida thunderstorm

“…The prior discussion assumes a simple electric dipole storm structure; however, the real world is obviously more complex [e.g., Stolzenburg et al, 1998]. For the case presented here, there are two distinct convective pulses.…”

Effects of charge and electrostatic potential on lightning propagation

“…Lower positive charge was evident in the cloud between 4.3 and 5.1 km [e.g., Marshall and Winn, 1982]. Negative charge was located between 5.2 and 5.8 km [e.g., Stolzenburg et al, 1998c]. Above 5.8 km, it is more difficult to identify the charge regions, except for the uppermost positive charge between 7.3 and 7.7 km, which seems to be a screening charge at the upper cloud boundary [e.g., Marshall et al, 1989;Marshall and Rust, 1991].…”

“…Their measurements indicated that IC flashes begin with ''upward propagating negative breakdown'' followed ''after a time delay'' by radiation associated with previously undetected positive polarity breakdown. Presumably, the two polarities of breakdown were initially driven by the primarily downward pointing electric field (E) commonly seen between the main negative and upper positive charge regions [e.g., Winn et al, 1978;Stolzenburg et al, 1998aStolzenburg et al, , 1998bStolzenburg et al, , 1998c. Shao and Krehbiel [1996] assumed that the horizontal branches of the bilevel IC flashes traveled through the main negative and upper positive charge regions of the cloud.…”

An overview of the lightning and atmospheric electricity observations collected in southern France during the HYdrological cycle in Mediterranean EXperiment (HyMeX), Special Observation Period 1

“…The lighter hydrometeors are transported upward, the heaviest being sustained at lower altitude in the cloud. Combined with cloud dynamics and cloud microphysics, electrification processes lead to dipoles, tripoles and even stacks of charged zones vertically distributed in the thundercloud (Stolzenburg et al, 1998;Rust et al, 2005). Between the charged regions, the ambient electric field can reach very high values, i.e., more than 100 kV m −1 (Marshall et al, 2005).…”