Hi,
I was reading about people who trigger lightening by launching small tethered rockets up into the atmosphere and I was wondering if a large metalized helium balloon tethered to the ground with a shielded copper cable could be used to generate electricity at the ground. I think the larger the metalized surface area is the more static electricity would be drawn through the cable towards the ground, where it could be captured. Any ideas on this?
cheers, Jamie Morken
in article noCub.429126$6C4.385364@pd7tw1no, Jamie Morken at snipped-for-privacy@hotmail.com wrote on 11/18/03 8:33 PM:
Thne amount of charge transferred is probably set almost entirely by the accumulated charge in the cloud. Tether resistance is just produces a heating loss. Thye electrostatic energy has to be dissipated somewhere.
Bill
There is a something called the "Fairweather Field" which is a constant discharge from the earth's atmosphere to the ground. I believe the magnitude is on the order of microamps. Many experiments have measured and proven the existence of this discharge and there are even small electrostatic motors that can be driven by a special apparatus.
Here is one link I found on Google:
Beachcomber
Tis article might demonstrate the complexity of an issue and shed some light for you:
Summary of a recent paper co-authored by Professor Vernon Cooray is enclosed. This is entitled, "The Franklin Lightning Conductor: Conditions Necessary for the Initiation of a Connecting Leader".
The Paper has important implications regarding validity of ESE (Early Streamer Emission) technology. It indicates that the artificial initiation of streamers would not increase the striking distance of any air terminal of practical size. This means that its protective range would not change either.
The above conclusion applies to electrode diameters up to about 0.7 m. For larger electrodes, the upper limit for the possible increase in the striking distance is only about 30% when the downward lightning leader is arriving directly above the ground object.
As the title of the paper indicates, the results are based not on the conditions sufficient for the generation of a connecting leader, but rather on the conditions necessary for it. Hence the stepped downward leader may have to come even closer than the estimated values to have a successful termination. Also, like in all lightning models, the results are based on several simplifying assumptions.
I have a couple of comments on the above important findings:
1) The protective range is governed by a configuration in which the downward leader is horizontally displaced from the ground object rather than directly above it. For this governing configuration, the maximum possible effect of artificial triggering is expected to be even less than 30%. 2) Any possible increase of the striking distance via artificial triggering in case of the larger electrodes is negated by the fact that the striking distance drops when size of the electrode is increased. This can be seen from Fig. 1 of [1]. This, together with the physical and economic impracticality of using air terminals of huge sizes lead to the conclusion that artificial triggering is useless under all conditions.We wish to thank Professor Aage E. Pedersen, for bringing this paper to our attention. We also wish to thank Professor Cooray for reviewing a draft of this message and for granting permission to use his paper.
REFERENCE:
[1] Abdul M. Mousa, "Validity of the Collection Volume Method/Field Intensification Method for the Placement of Lightning Rods on Buildings", Proceedings of ICLP 2002, Vol. II, pp. 809-814.Abdul M. Mousa, Ph.D., P. Eng., Fellow IEEE abdul snipped-for-privacy@hotmail.com
I took the liberty to post the copy of the document Mr. Abdul mentioned on my own webside:
Art.
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