In both cases, pseudo-GLM observations were created from ground-based lightning mapping array data by generating flash event densities with a resolution approximately equal to the resolution of the GLM at its nadir. These psuedo-observations were then assimilated to produce analyses of each storm, and sensitivity tests were done to determine 1.) The optimal observation error values to use during the assimilation process; 2.) The effectiveness of different EnKF observation operator relationships, with a focus on relationships between graupel mass and total flash rates; and 3.) The utility of temporally averaging observations over a range of different time periods (with a maximum of 6 minutes) to smooth short time-scale variations in flash rates and to lower the computational cost of the assimilation process.
Results from these experiments will be presented and compared to observations of each storm as well as to EnKF analyses from each storm produced using the more established technique of assimilating radar radial velocity data.