On the Electrification of Rapidly Freezing Water Droplets at Temperatures near Homogeneous Nucleation Temperature

[摘要] The electric charge on freezing water droplets with sizes of 20 to 100μ was measured in a state of free fall at temperatures of -25°C to -40°C. As a result of the measurements, it was noted that the number of negatively charged droplets was greater than that of positively charged ones. It was also found that the mean value of the negative charge was much greater than that of the positive charge in a temperature region colder than -35°C, especially at water homogeneous nucleation temperature; -40°C.This result suggests that the freezing water droplets obtained a negative charge by some mecha- nism, when they were frozen very rapidly. However it appears that the electrification mechanism of the freezing water droplets around -40°C was different from that presented by Mason and Maybank, or Stott and Hutchinson.

[学科分类] 大气科学