A case study of the Thunderstorm Research International Project. 2. Interrelations among the observable parameters controlling electrification

Journal Article · Fri Apr 20 00:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JD095iD05p05435· OSTI ID:5042544

Nisbet, J S; Kasha, J R; Forbes, G S ^[1]

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1. Pennsylvania State Univ., University Park (United States)

In Part 1 of this paper, the data obtained at the time of the Thunderstorm Research International Project storm at the Kennedy Space Center on July 11, 1978, are discussed and analyzed in a model-independent manner. Here the parameters of the electrical system that would be consistent with these observations are discussed. Three-dimensional electrodynamic modeling of the thundercloud electrification allowed estimates to be made of the current moments and electrical power generated continuously throughout the evolution of the two cells of the storm that were studied. The evolution and configuration of the currents were consistent with the separation of an originally neutral ensemble of particles by gravity in the region of 7 km in the region close to the maximum of the updraft velocity. After about 370 s the effect of wind shears would have caused the particles to separate in the convective system of the cells. Rain did not appear to be the dominant charge carrier. The current moments generated were compared with the current moments transferred by intercloud and cloud-to-ground lightning. It is shown that for the southern cell, which produced a charge moment of about 8.4 (MC m), lightning utilized about 84% of the charge moment separated, while for the northern cell, which produced about 1.1 (MC m), this figure was approximately 60%. It was shown that the times of initiation and maximum electrical power generated correspond best with the normalized mass above 7.5 km. It was deduced that the median diameter heavier particles had a fall velocity of about 3 m/s. The generator currents, flash rates, cloud conductivities, and mean charge per flash were used to estimate the volume associated with the lower region of current divergence.

• OSTI ID: 5042544
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:D5; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
LIGHTNING
ELECTRODYNAMICS
CAPE KENNEDY
CHARGE TRANSPORT
CLOUDS
DATA ANALYSIS
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRIC GROUNDS
ELECTRIC POWER
MATHEMATICAL MODELS
POWER GENERATION
RAIN
RESEARCH PROGRAMS
STORMS
THREE-DIMENSIONAL CALCULATIONS
ATMOSPHERIC PRECIPITATIONS
DEVELOPED COUNTRIES
DISASTERS
ELECTRIC DISCHARGES
ELECTRICAL PROPERTIES
FEDERAL REGION IV
FLORIDA
NORTH AMERICA
PHYSICAL PROPERTIES
POWER
USA
540110*