IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Graupel charging in stratiform cloud conditions
Autor/es:
RAFAEL A. LIGHEZZOLO; NESVIT E. CASTELLANO; RODOLFO G. PEREYRA; ELDO E. AVILA
Lugar:
Río de Janeiro
Reunión:
Conferencia; XIV International Conference on Atmospheric Electricity; 2011
Resumen:
New laboratory measurements of the charge transfer in collisions between vapor grown icecrystals and a graupel particle (1 mm radius) growing by riming are presented in this work. The experiments were conducted for ambient temperatures between ?7°C and ?13°C, air velocities between 1 and 3 m/s and effective liquid water content up to to 0.7 g/m3, with the goal of studying the performance of this mechanism under microphysical conditions similar to those found in stratiform cloud regions. The ice crystal concentration was determined in each experiment, which allows to estimate the average charge transfer per collision. Chargediagrams of the sign of the electric current on the graupel as a function of the ambient temperature and the effective liquid water content for each velocity are presented. The magnitude of the charge transfer per collision ranges from 0.01 to 0.2 fC.