Thunder is good, thunder is impressive; but it is lightning that does all the work.
– Mark Twain.
A single lightning flash can last for 0.2 seconds, made up of series of lightning strokes with each of them sustaining for about 60 to 70 microseconds. About 1.4 billion flashes hit the Earth every year though the frequency is not evenly distributed. An average stroke is around 6 miles long. But how long is ‘the longest’?
World Meteorological Organization, on june 26, confirmed two new world records for the longest reported distance and the longest reported duration for a single lightning flash in Brazil and Argentina respectively. The new records were double the previous entries.
World Meteorological Organization’s Committee on Weather and Climate Extremes, which maintains official records of global, hemispheric and regional extremes found that:
The greatest extent for one single lightning flash is the one that covered a horizontal distance of 709 ± 8 km (440.6 ± 5 mi) across parts of southern Brazil on October 31, 2018. The previous record for the longest distance covered by a single lightning flash is 321 km (199.5 miles) on June 20,2007 across the US state Oklahoma.
The greatest duration for a single lightning flash is 16.73 seconds from a flash that developed continuously over northern Argentina on March 04, 2019. Past record for the same lasted for 7.74 seconds from a single lightning flash that struck on August 30, 2012 over Provence-Alpes-Côte d’Azur, France.
The previous evaluations that determined the flash duration and extent records used data collected by ground-based lightning mapping array networks(LMA). Many scientists admitted that there are limitations on recording the scale of lightning for any existing LMA. To identify mega flashes beyond this range, certainly, we require a lightning mapping technology that could help on a larger observational domain. Recent advancements in space-based lightning mapping provide us with the ability to measure the extents continuously over a broad geospatial domain.
These new instruments include the Geostationary Lightning Mappers (GLMs) on the R-series Geostationary Operational Environmental Satellites (GOES-16 and 17) that recorded the new lightning records and their orbiting counterparts from Europe (the Meteosat Third Generation (MTG) Lightning Imager) and China (FY-4 Lightning Mapping Imager). These advanced space-based instruments will provide near-global coverage of total lightning that is both intracloud flashes and cloud-to-ground flashes.
Michael J. Peterson, of the Space and Remote Sensing Group (ISR-2) of Los Alamos National Laboratory, USA says that the substantial enhancement of our space-based remote sensing capabilities has allowed the detection of previously unobserved extremes in lightning occurrence, known as ‘mega-flashes’. Mega flashes are defined as horizontal mesoscale lightning discharges that reach hundreds of kilometres in length.
More than 20,000 people die of lightning and thunder. It is impossible to have thunderstorms without lightning. But there could be lightning without thunderstorms. If you could see lightning but not hear the thunder, then you are too far away from the region that’s struck by the lightning. Thunders can only be heard up to a distance of 3-4 miles and is based on certain factors. But lightning can be seen up to 100 miles.
In the case of thunderstorms, follow the 30-30 rule. If lightning is followed by thunder within 30 seconds, then stay indoors for at least 30 minutes from the last thunder strike. This makes sure that you are far away from the gates of heaven.
-Keerthana Vengatesan
Reference: WMO
Have a look at the Lighning view from Space Station
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