- 13 Aug 2018 Arctic lightning event
- 不明な地域 ()
Between 9 and 13 August 2019, a series of thunderstorms were recorded by the US National Weather Service in the high Arctic. The most extreme lightning flash associated with these storms occurred at 09:26 UTC on 13 August 2019 and was detected at 89.53°N – a mere 52 kilometres (32 miles) from the geographic North Pole. The discharges were picked up by the GLD360 lightning detection network, created and managed by the environmental monitoring company Vaisala (Finland).
A handful of events north of 85°N – or about 488 km (300 mi) away from the North Pole, have been detected. The most prolific of these storms occurred in Aug 2019, producing nearly 50 flashes north of 85°N.
The GLD360 lightning detection network has been in operation since 2009, though its archives only begin from 2012. The system is based on a series of receivers located around the world that pick up electromagnetic (radio) signals produced during a lightning discharge (both intracloud and cloud-to-ground). The sensors log the time that the waves take to reach them, as well as their direction of arrival, so that when multiple receivers’ data is combined, it’s possible to calculate the location and time that the discharge occurred.
Some meteorologists have suggested that global warming could be the cause for this previously undocumented event (though it may have happened before and gone undetected). As Arctic sea-ice continues to melt and ocean temperatures rise, it allows warm, moist air to accumulate at ever-higher latitudes in sufficient quantity to create the unstable conditions required for a thunderstorm to form.