IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
Charge separation in thunderstorm conditions
Autor/es:
PEREYRA R. G.; BÜRGESSER R. E.; AVILA E. E.
Revista:
JOURNAL OF GEOPHYSICAL RESEARCH
Editorial:
American Geophysical Union
Referencias:
Lugar: Washington, USA; Año: 2008 vol. 113 p. 1 - 12
ISSN:
0148-0227
Resumen:
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A laboratory
investigation of the electric charge transfer in collisions between vaporgrown ice
crystals and a riming target is presented in this work. A series of experiments
were conducted for ambient temperatures between -8C and -29oC, air velocity of 8 m s-1, and effective liquid
water content from 0.5 to 10 g
m3, with the goal of studying the performance of the noninductive mechanism
under a wide range of temperature and liquid water content. At low temperatures
(below -19oC), the results revealed no dependence of the charge separated per
collision upon variations of the liquid water content. While at temperatures
above -19oC, the efficiency of the graupel charging could decrease as the
liquid water content increases, as a consequence of the decrease of the probability
that the ice crystals impact and rebound from the graupel surface in the dry growth
regime. We found that the dominant sign of the graupel charging was negative
for temperatures below -15oC and positive at higher temperatures. A simple
functional representation of our laboratory results is given so that they can
be incorporated in cloud electrification models.