The WGLC global gridded lightning climatology and time series

Abstract

Abstract. Lightning is an important atmospheric phenomenon and has wide-ranging\ninfluence on the Earth system, but few long-term observational datasets of\nlightning occurrence and distribution are currently freely available. Here, we\nanalyze global lightning activity over the second decade of the\n21st century using a new global, high-resolution gridded\ntime series and climatology of lightning stroke density based on raw data from\nthe World Wide Lightning Location Network (WWLLN). While the total number of\nstrokes detected increases from 2010–2014, an adjustment for detection\nefficiency reduces this artificial trend. The global distribution of lightning\nshows the well-known pattern of greatest density over the three tropical\nterrestrial regions of the Americas, Africa, and the Maritime Continent, but\nwe also noticed substantial temporal variability over the 11\xa0years of record,\nwith more lightning in the tropics from 2012–2015 and increasing lightning in\nthe midlatitudes of the Northern Hemisphere from 2016–2020. Although the\ntotal number of strokes detected globally was constant, mean stroke power\ndecreases significantly from a peak in 2013 to the lowest levels on record in\n2020. Evaluation with independent observational networks shows that while the\nWWLLN does not capture peak seasonal lightning densities, it does represent\nthe majority of powerful lightning strokes. The resulting gridded lightning\ndataset (Kaplan and Lau,\xa02021a,\xa0https://doi.org/10.5281/zenodo.4774528)\nis freely available and will be useful for a range of studies in climate,\nEarth system, and natural hazards research, including direct use as input data\nto models and as evaluation data for independent simulations of lightning\noccurrence.\n