30 years ago I studied electricity and electronics and my instinct tells me that the risk/altitude equation is not linear.
No later than today I experienced the frightening experience of rocks making static sounds and my hair pointing the sky when I reached the summit of Mauna Loa at 4000m while a thunder cloud surrounded the moutain.
My thinking: If you are the chosen path for lightening at very low altitude, you will absorb the immense current required to ionise the long path from cloud to earth. but if you are in the cloud on a very high mountain, there may not be such great difference in electron charge to cause a dangerous spark like on ground. What I am missing is the theroatical principles to explain it. Or maybe I’m wrong. Any ideas?
A potential of about 20,000 volts per inch of distance is required to ionize a path through the air at sea level and allow current to flow. Once the path is ionized, the voltage requirement to maintain the path is much lower, and you end up with massive current flowing along that path.
At high altitudes the atmospheric pressure is lower, so the ionization requirement (volts per inch) is lower, but not by enough to matter when it comes to lightning jumping gaps of many thousands of feet versus the relative fragility of a living creature. Lightning can and does hit mountain peaks, and people do get killed by it. If your hair was standing on end and the rocks around you were crackling (BTDT), then you were damn lucky not to have been struck.
I am aware of the principles your are refering to and my question is not clear I guess.
Yes Lightening strikes on top of mountains but how high are those mountains compared to the thunder cloud involved?
Here is one of many example where high static electricity voltage create the exact same phenomenon (sound as well if you wehe to listen closely) and zero danger is involved;
I am also aware of ‘available current’ versus voltage alone and I know that cloud-earth discharge can produce much more current than any Tesla coil.
My question relates more to the altitude relative to the cloud that has the electric charge. Obviously if you are above the cloud, no risk exist. Now what if you are inside the cloud as I was? Yes if you are on a mountain top that happens to be lower than the cloud’s base there is danger.
I suspect that there was in fact very little danger where I was. Anyone knows the laws involved that could prove or contradict my thinking?
Cloud to cloud lightening sure, but it has nothing to do with the increased risk involved when I am standing on the top of a moutain in the middle of one cloud.
I think the so called ‘increased risk’ people refer to involves cloud-me-ground. And that’s what my doubt is about.
Cloud to cloud lightening sure, but it has nothing to do with the increased risk involved when I am standing on the top of a moutain in the middle of one cloud.
I think the so called ‘increased risk’ people refer to involves cloud-me-ground. And that’s what my doubt is about.
Voltage has nothing to do with injury to a human. It is all about amperage. A 12V car battery can kill you, but a 100kvolt van de Graff generator will only make your hair stand up .
…and yes voltage causes current as long as the source behind has the capacity to deliver it. That’s why it is perceived that a 12v car battery can kill; it could indeed if it had other equipment connected to it.
I suspect that having a cloud anywhere near a mountain top (and this includes “touching” the mountain top, however you define “touching” for a thing with such an ambigious/amorphous boundary as a cloud) puts the mountain top and anyone/anything on it at risk for a cloud-to-ground strike. The altitude is not the problem so much as the difference in electrical potential between the cloud and the mountain top.
