by Odd_Man_In » Sun May 13, 2018 5:53 pm
Why is volcanic lightning still a mystery in 2018 A.D.? Am I missing something here? The source / cause is pretty much the same as storm lightning - turbulent motion of a cloud of polar particles, namely water droplets, plus, in the case of a volcano, silicate dust particles just pulverized.
The most abundant gas in a volcanic eruption, somewhere in excess of 90% of the entire gas budget in most eruptions (there are a few rare exceptions), is water. That percentage exceeds 99% in basaltic eruptions, especially on ocean islands. In fact, the only reason any magma, especially a low viscosity one such as basalt, produces ANY cloud at all is due to the presence of water either in the magma or coming in contact with the magma in the substrate.
Volcanology lesson aside, volcanic clouds obviously are more (rock) dust laden than are atmospheric clouds, so the presence of micron to submicron dustparticles increases overall electrical charge density, meaning that lightning is more likely in a volcanic cloud than in an atmospheric one. Eruptions are fairly rare and someone witnessing or recording lightning is rare, and rare times rare equals rare-squared, but volcanic lightning isn't rare when the sample set is limited to volcanic eruptions, especially those that involve enough water to produce a cloud.
Why is volcanic lightning still a mystery in 2018 A.D.? Am I missing something here? The source / cause is pretty much the same as storm lightning - turbulent motion of a cloud of polar particles, namely water droplets, plus, in the case of a volcano, silicate dust particles just pulverized.
The most abundant gas in a volcanic eruption, somewhere in excess of 90% of the entire gas budget in most eruptions (there are a few rare exceptions), is water. That percentage exceeds 99% in basaltic eruptions, especially on ocean islands. In fact, the only reason any magma, especially a low viscosity one such as basalt, produces ANY cloud at all is due to the presence of water either in the magma or coming in contact with the magma in the substrate.
Volcanology lesson aside, volcanic clouds obviously are more (rock) dust laden than are atmospheric clouds, so the presence of micron to submicron dustparticles increases overall electrical charge density, meaning that lightning is more likely in a volcanic cloud than in an atmospheric one. Eruptions are fairly rare and someone witnessing or recording lightning is rare, and rare times rare equals rare-squared, but volcanic lightning isn't rare when the sample set is limited to volcanic eruptions, especially those that involve enough water to produce a cloud.