Even in the 21st Century, there are several natural phenomena which have been difficult to explain even when modern science and technology has been employed to study such phenomena. Dirty thunderstorms involving lightning generated within a volcanic cloud formed as a result of a volcanic eruption are an example of such phenomena whose cause is yet to be fully explored and explained. Though till now the geysers of molten lava and ash laden clouds of volcanic eruptions had captured the attention of the world, the rare sight of lightning within the volcanic clouds has spurred worldwide interest in investigating the cause of occurrence of this spectacular phenomenon.
Where does it occur?
Dirty thunderstorms might not be as rare as we deem it to be, as, most of the time, human eyewitnesses are not present on site to visualize a volcano erupting and the lightning striking within its dark, ominous clouds. However, on some occasions, nature photographers have managed to capture stunning images of this dramatic phenomenon on their camera which has provided us with some information of the places where these dirty thunderstorms occur. For example, one such dirty thunderstorm event, occurring above the Chaiten Volcano in Chile, was captured by the photographer Carlos Gutierrez. Such thunderstorms have also been reported to happen above the Sakurajima volcano in Japan, the Alaskan volcano of Mount Augustine, and the Sicilian volcano of Mount Etna in Sicily, Italy. In May of 2010, Iceland's Eyjafjallajökull volcano was also reported to exhibit dirty thunderstorm-like events.
What Happens During a Dirty Thunderstorm?
The inability to properly record the occurrence of dirty thunderstorms and the event being associated with the highly unpredictable volcanic eruptions has kept scientists wondering about the real cause of this phenomenon. Under normal circumstances, lightning is created during thunderstorms when ice particles collide with each other to generate charge. In the case of dirty thunderstorms, the volcanic eruption itself is unable to produce lightning but if the ash, rock fragments, and ice spewed out by the volcano collide with each other, it might generate static charges leading to lightning. This explanation is has been mentioned in National Geographic news. However, without firm investigations, it is difficult to provide a conclusive explanation of the occurrence of dirty thunderstorms.
What the future holds?
Even though not much is known about the dirty thunderstorms, one fact is admitted by all and that is quite contrary to the name, the dirty thunderstorms do present a spectacular sight and hence, videos and photographs of this unique natural phenomenon have been widely published in leading media outlets. Even though public interest in this phenomenon is quite intense, there are few who would actually risk their lives to dare to capture images of lightning over actively erupting volcanoes. To find answers to this mystery, a recreation of conditions in the laboratory might, however, provide some clues regarding the source cause of this amazing natural wonder.