Abstract
Many studies have shown that the characteristics of lightning such as
size and peak current differ between ocean and continental
thunderstorms. In general, the lightning in oceanic thunderstorms are
larger and have higher peak current than in continental thunderstorms.
The reason for these differences have been stipulated to be related to
differences in thermal properties and aerosol concentration, however,
there is still disagreement over which is the dominant mechanism. In
this study, we focus on how thunderstorm trends, as opposed to lightning
trends (i.e., flash density), are affected by these mechanisms. We
develop a lightning clustering algorithm that takes individual lightning
strokes and creates thunderstorms based on their spatiotemporal
proximity. We use lightning data from the Earth Networks Total Lightning
Network and compare storms from the Eastern U.S.A. to storms off that
coast, where the detection efficiency of the network is still good. Once
these thunderstorms are obtained, we can split them into ocean and land
thunderstorms and compare various characteristics (size, duration, flash
rate, polarity and IC/CG ratio, etc.) to determine if any differences
stand out. In this presentation, we will discuss the clustering
algorithm used, analyze the results of the study, and discuss
implications.