A Relationship between Lightning Flash Rate and Convective Variables on a Large-Scale Grid

This study utilities the CMIP5 datasets and TRMM datasets to establish a relationship between large-scale environments and lightning rate in the tropics and sub-tropics. First, convective features (CF) are defined from TRMM datasets. Then, some of the essential environmental variables are obtained from the CMIP5 historical experiments and compared with properties of CFs. In the climate models, lightning is a diagnosed variable. Uncertainty are introduced in estimation of lightning rates based on empirical relationship, which is generally established based on one to two variables only in the literature. In this study, an empirical relationship is constructed based on multiple variables, including convective mass flux, convective precipitation, CAPE, CIN, low level wind shear, and LCL. Climate models tend to underestimate the magnitude of the convective variable and lightning flash rates. Globally, lightning flashes are expected to increase in a warmer climate. An attempt is made to understand the trends of lightning over the globe based on Representative Concentration Pathway (RCP) projection experiments. We also discuss the variation of results from various resolutions of the climate models.