Electric field structure in an active part of a small, isolated thundercloud

Abstract

A balloon carrying an electric field meter and a standard meteorological radiosonde rose into a relatively small, isolated thunderstorm in central New Mexico on July 16, 1977. The electric field, E, versus altitude between 3200 m (surface) and 7000 m above sea level can be explained reasonably well by the following charge distribution: (1) a 130 m thick layer of positive charge just above the surface with a density of 1.7 × 10−9 C/m3; (2) a localized 1 C of positive charge moving downward on rain with a velocity of 8 m/s at a horizontal distance of 420 m from the balloon; (3) a 1‐km thick ‘layer’ of negative charge between 4800 and 5800 m above sea level with a density of about −5 × 10−9 C/m3. This negative charge spanned a temperature range of about −2 to −5°C. Between 7000 and 10,000 m above sea level, the balloon was near the edge of the cloud where E was low and principally horizontal. Above 10,000 m the balloon ascended into an anvil cloud that was apparently positively charged.

Hydrometeor mass, number, and space charge distribution in a “Hector” squall line

“…These charges are of similar magnitude as those estimated by electric field sounding in thunderstorm [Winn et al, 1981]. After comparison of space charge from hydrometeors with space charges estimated by electric fields in clouds, Marsh and Marshall [1993] reported that both low-level positive and midlevel negative space charges reside primarily on hydrometeors.…”

Vertical Electric Fields and Field Change Parameters Due to Partly Inclined Lightning Leader Channels

“…In contrast, when the same parameter is determined by VHF mapping, Radar pictures or balloonborne measurements, this range was rather narrow. For examples, Proctor [17] radar pictures: 3.1-5.1 km above ground level for 26 flashes; Proctor [18] VHF mapping: group 1, 4.4-5.7 km amsl for 431 flashes and group 2, 7.5-9.7 km amsl for 337 flashes; Winn et al [29] balloon-born instruments: 4.8-5.8 amsl.…”

“…This characteristic of leader and return stroke fields (static fields) provides information to estimate the charge source heights. Taking measurements by balloon-borne instruments is also a popular method [27][28][29][30]. In some cases more than one of these techniques are applied to obtain more precise information.…”

Role of Corona Space Charge in Electrification of Convective Thunderclouds

“…Standler and Winn (1979), Chauzy and Raizonville (1980), Winn et al (1981) reported space charge density, 1 nCm-3, 2-4 nCm-3 and 1.7 nCm-3, respectively near the ground surface. Standler and Winn (1979) also established the following relation between corona current density, Jcr(t) and ambient electric field Eout(t), at the ground :…”

“…The positive space charge is produced by corona near the ground surface when the electric field is intense as it often is under thunderclouds [Livingston and Krider (1978), Standler and;Winn (1979), Chauzy and Raizonville (1980), Winn et al (1981)]. Standler and Winn (1979) reported that the rate of ions production by corona is a rapidly increasing function of the ambient electric field at the ground surface, and an estimated threshold value of electric field at the ground surface to initiate corona is about 5KVm-1.…”