• lightning;
  • convective cloud;
  • parameterization

[1] The relationship between lightning activity and some aspects of a convective cloud has been carefully studied in the fields of science and engineering. Coincident data from the precipitation radar (PR) and the lightning imaging sensor (LIS) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite are used to examine the correlation between the number of lightning flashes per second per convective cloud (NFSC) and the cold-cloud depth. The cold-cloud depth is defined as the height from the melting level, which is the altitude at 0 degree, to the storm height. It is found that the NFSC is approximately proportional to the fifth power of the cold-cloud depth. In addition, it should be noticed that the relationship does not have regional dependencies. Two simple dimensional analyses indicate that the fifth power of the cold-cloud depth is proportional to the stored static electric energy and to the charging rate in the convective cloud.