[pirunner (OP)]

What causes the buzzing noise you hear when you're close to a power line?

[paul.fr]

corona discharge, the guys and gals at wikipedia explain it better than i can
http://en.wikipedia.org/wiki/Corona_discharge

[Alandriel]

Very interesting - I had no idea.

I always get a very funny feeling near high power lines, especially when they're buzzing - now I know why.
Thanks for that link!

[pirunner (OP)]

Interesting! Thanks! - And here I thought it was moiture or dust in the air.

[techmind]

Interesting! Thanks! - And here I thought it was moiture or dust in the air.

The weather does have a significant -but indirect- effect. You get corona discharge where there is particularly high electric field, so you need a high voltage, but irregular or sharp objects (at high voltage) will also have much higher local electric fields around them than smooth polished objects. Dirt and dust can accumulate on the cables, making them rougher, and enhancing the corona discharge. A decent rainstorm will then wash off much of the debris leaving them smoother and reduce the corona discharge. I don't know whether humidity has much effect - this is not really my field of expertise.

[paul.fr]

Some good points there by Techmind.

corona discharge is affected by humidity and water ,be it rain or fog. Water increases the conductivity of the air and so increases the intensity of the discharge.

[pirunner (OP)]

So if I'm getting this right, I should be able to listen to the power wires right before a downpour (before all the debris is washed off of the lines and the humidity is roughly 100%) and the day after the downpour (when the lines are clean and smooth, and let's just say the humidity went to the opposite extreme) and be able to hear a noticeable difference in the intensity of the buzz??