Abstract. Lightning is an important atmospheric phenomenon and has wide-ranging
influence on the Earth system, but few long-term observational datasets of
lightning occurrence and distribution are currently freely available. Here, we
analyze global lightning activity over the second decade of the
21st century using a new global, high-resolution gridded
time series and climatology of lightning stroke density based on raw data from
the World Wide Lightning Location Network (WWLLN). While the total number of
strokes detected increases from 2010–2014, an adjustment for detection
efficiency reduces this artificial trend. The global distribution of lightning
shows the well-known pattern of greatest density over the three tropical
terrestrial regions of the Americas, Africa, and the Maritime Continent, but
we also noticed substantial temporal variability over the 11 years of record,
with more lightning in the tropics from 2012–2015 and increasing lightning in
the midlatitudes of the Northern Hemisphere from 2016–2020. Although the
total number of strokes detected globally was constant, mean stroke power
decreases significantly from a peak in 2013 to the lowest levels on record in
2020. Evaluation with independent observational networks shows that while the
WWLLN does not capture peak seasonal lightning densities, it does represent
the majority of powerful lightning strokes. The resulting gridded lightning
dataset (Kaplan and Lau, 2021a, https://doi.org/10.5281/zenodo.4774528)
is freely available and will be useful for a range of studies in climate,
Earth system, and natural hazards research, including direct use as input data
to models and as evaluation data for independent simulations of lightning
occurrence.
Review of "The World System and the Earth System: Global Socioenvironmental Change and Sustainability Since the Neolithic," by Alf Hornborg and Carole Crumley, eds.