Gridded Hourly WWLLN Lightning Flash Density Data -- 1/1/2016 - 12/31/2023 12km CONUS

CMAQ-ready gridded hourly observed lightning flash density data for the 12US1 domain from the World Wide Lightning Location Network (WWLLN) with scaling (WWLLNs). These daily 24-hour input files contain one 2D variable “LNT” (lightning flash density in flashes/km2/hr, dimensions: (TSTEP, LAY, ROW, COL), with LAY=1) and are used for CMAQ’s lightning NO module to produce inline lightning NO emissions that are distributed vertically by the lightning NO module (https://gmd.copernicus.org/articles/12/3071/2019). To use the inline lightning NO production, the following environmental variables in CMAQ runscript need to be set: setenv CTM_LTNG_NO Y setenv LTNGNO "InLine" setenv USE_NLDN Y (will be changed to USE_FLASH in next CMAQ release) setenv NLDN_STRIKES ${IN_LTpath}/WWLLNs_12km_60min_${YYYYMMDD}.ioapi (The NLDN_STRIKES will be changed to FLASH_FILE in next CMAQ release) setenv LTNGPARMS_FILE ${IN_LTpath}/LTNG_AllParms_12US1.ncf (should be available in the same directory with the WWLLNs data or otherwise be instructed). File Location and Download Instructions: Link to Gridded 12US1 WWLLN Lightning Flash and Emissions Data Download instructions