Flash Rates Versus Flash Area and Microphysical Properties for Multiple Storm Types over Northern Alabama

Currently there exist research that states that areal flash length may be important in the calculation of nitrogen oxides (NOx) produced by lightning (LNOx). Other research have also shown that flash rate and flash size are opposed: Flashes that develop within the convective core and updraft region of mesoscale convective systems (MCSs) and supercells occur more frequently, but with smaller flash areas as compared to flashes that developed or propagated further away from or behind the convective core (i.e. in the stratiform region of MCSs or anvils of supercells). In addition, some larger flashes develop in the convective region, but then propagate into the stratiform/anvil region of a storm. Furthermore it has been shown that flash rates are correlated to certain radar variables that can be used to infer the microphysical behavior of the storm. Some of these include the precipitation ice mass and volumes and reflectivity threshold volumes in the mixed-phase regions (between 0 °C and -40°C) as well as non-precipitation ice and reflectivity threshold volumes at temperatures colder than -40 °C in the anvil or stratiform region of supercells and MCSs. For this study, we will verify whether the above findings are applicable across multiple storm types (i.e. ordinary multicellular convection, supercells, and MCSs, with varying flash rates). The region of focus for this work will be Northern Alabama. Through this research we will also attempt to show that flash rate and flash size (calculated using the “convex hull area” method) are indeed opposed, even for different storm types. In addition, a goal will be to verify which radar-derived variable, or combination thereof (precipitation ice, non-precipitation ice, reflectivity volumes at different temperature levels, as well as ice in convective core versus anvil/stratiform regions), control the flash size and whether these mechanisms vary per storm type.