Electric rain

[Gymnast]

Every radio amateur know of electric rain. I was once a radio amateur, and in Denmark I guess it happended about five times a year. When the rain hid the antenna, it caused noise from your receiver. Sometimes you got afread that it might damage the receiver.

Electric rain can occur independent of thunderstorms.

I have been involved in one outdoor system, which failed occationally, and eventually you did find the cause: electric rain. The system involved some insulated parts of electonics with some cables and so making an electric capacitance. The capacitance was charged due to electric rain, and the spark over occured at a place causing damage. The idea is that the raindrops are charged and carry a charge to the point it hits. In summer time the insulation resistance of the cables was low due to the temperature, and therefore the problem did not occur in the summer.

I think I have read some place that a current of about 1 microamp per square meter may occur.

Do you know of any research on electric rain?
Do you know of building codes dealing with this phenomena?

 

[bphgravity]

Now you are getting a little "out there".

Unless you can provide some time of substanial explanation and documentation of this "phenomena", I don't buy it for one second...

 

[drbond24]

I tend to agree with bphgravity. If this is a valid phenomena, we will need more information than this to comment any further.

I'm just curious: if your equipment failed and you later discovered the point of failure, what specific evidence was there that this alleged electric rain was the culprit as opposed to anything else?

Also, attempting to quantify the amount of charge in a raindrop by giving a value in microamps per square meter doesn't make any sense. You would probably want the quantity of charge in Coulombs and you certainly would need a volume, not an area (i.e. cubic meters, not square meters).

 

[al hildenbrand]

Sun spots?

Solar wind?

 

[winnie]

This sounds to me like static charging caused by dust particles in moving air. Water droplets can certainly carry static charge, and moving water droplets can generate large electrical potentials.

If this is the sort of issue being described as 'electric rain', then normal grounding and bonding requirements will eliminate any issues. An antenna would be particularly sensitive to this, because you have chunk of metal _isolated_ from ground, connected to a sensitive amplifier.

-Jon

 

[weressl]

Yep, and there are folks who swear that the Earth IS flat.

Yep, and there are folks who swear that the Earth IS flat.

Every radio amateur know of electric rain. I was once a radio amateur, and in Denmark I guess it happended about five times a year. When the rain hid the antenna, it caused noise from your receiver. Sometimes you got afread that it might damage the receiver.

Electric rain can occur independent of thunderstorms.

I have been involved in one outdoor system, which failed occationally, and eventually you did find the cause: electric rain. The system involved some insulated parts of electonics with some cables and so making an electric capacitance. The capacitance was charged due to electric rain, and the spark over occured at a place causing damage. The idea is that the raindrops are charged and carry a charge to the point it hits. In summer time the insulation resistance of the cables was low due to the temperature, and therefore the problem did not occur in the summer.

I think I have read some place that a current of about 1 microamp per square meter may occur.

Do you know of any research on electric rain?
Do you know of building codes dealing with this phenomena?

Yep, and there are folks who swear that the Earth IS flat.

Laszlo(Former amateur ham -sandwitch.)

 

[catchtwentytwo]

I've tried to Google this (in a variety pf phrases) without finding anything related to the "phenomena" you've described. Please provide a link to some documentation describing it.

 

[mdshunk]

During an electric rainstorm, it is mandatory that you wear a tin foil hat to protect yourself.

Could be that spy satellite that's crashing to earth as we speak.

http://www.reuters.com/article/scienceNews/idUSN2628127620080126

 

[76nemo]

Note that on this forum, comical comments are not personal jabs. I have worked with electrical and electronic app's for about 13 years. Never heard this discussion. Never fooled with ham. I am listening though. Please add.

 

[tkb]

During an electric rainstorm, it is mandatory that you wear a tin foil hat to protect yourself.

Could be that spy satellite that's crashing to earth as we speak.

http://www.reuters.com/article/scienceNews/idUSN2628127620080126

Don't forget the bubble wrap suit. :grin:

 

[dbuckley]

I used to be a radio amateur (ex G1XRY) and can safely say I have never heard the phrase "electric rain", nor have i experienced my receiver trying to blow it self up during a rainstorm...

 

[nakulak]

It is well known that there is a difference in charge between clouds and ground. Its well known that lightning conducts charge to ground. Its not such a stretch that rain droplets should be charged, and thus carry a manner of current (in the form of discrete charges). whether or not this is the OP's description or not I don't know, but seems to me he got an earful (regardless that he may have assumed that the charged raindrops contributed to what is more likely an insulator or wiring failure). Anyhow, here's a few articles:

transfer of charge between cloud and groundhttp://www.agu.org/pubs/crossref/1997/97JD00007.shtml


charged raindrops at altitude Clearly, raindrops are charged.

charges of droplets in waterfall http://www.atmos-chem-phys.org/7/2271/2007/acp-7-2271-2007.pdf

thunderstorm electrification of hail http://www.sciencemag.org/cgi/reprint/151/3711/686.pdf

droplet size and shape as a function of electric charge - study (note reference to thunder cloud droplet formationhttp://news.uns.purdue.edu/x/2008a/080107BasaranDrops.html

 

[RayS]

Kind of like a huge Van DeGraff (spelling?)generator...

 

[bphgravity]

None of the links in nakulak's post provide any indication that damage being described in the OP is even remotely possible.

I still believe something else is going on that would better describe why the radio equipment is being damaged.

I would be more inclined to believe the radio mast is acting as an electric "tether" and stripping electrons out of the air and into the electrical parts. I think that is a far stretch as well, but more probable than charge rain…

 

[Gymnast]

Does electric rain exsist?

Does electric rain exsist?

I tend to agree with bphgravity. If this is a valid phenomena, we will need more information than this to comment any further.

I'm just curious: if your equipment failed and you later discovered the point of failure, what specific evidence was there that this alleged electric rain was the culprit as opposed to anything else?

I think I can sum up this and many other comments: Is this "electric rain" a phenomena to be considered at all?

Well - I hope with this question here to find someone who may have heard something about this at all. I have not suceeded yet.

I have been 16 years in the business of EMC consulting and EMC tests. Most times we have been able to simulate some failures doing transient tests ESD or other phenomena imposed on equipment. But after extensive tests on the refered system of about 500 masts in Denmark we could not reproduce the failure. Several EMC specialists have looked at the problem. Then we tried to look for other explanations, and electric rain is one that can be valid. I don't say it is right or that another explanation could be valid. But this is the only direct case I know of. But I have never considered electric rain either.

I have tried to search the internet too with no result. But maybe my english is to bad for using correct alternative words.

I think it should be easy to get some evidence among radio amateurs, that they do have noise on their receivers during rain - sometimes. Most rain showers did not create noise at all. From my expierience - when happended - the intencity of rain and noise in radio was very proportional - just like every rain drop carried some charge. So I think that such model could fit my expierience. I recall that nearby other radio amateurs had the same expierience the same days with electric rain.

Also, attempting to quantify the amount of charge in a raindrop by giving a value in microamps per square meter doesn't make any sense. You would probably want the quantity of charge in Coulombs and you certainly would need a volume, not an area (i.e. cubic meters, not square meters).

In general from electrostatic theory I think that you can say that charge can be is present on surfaces in air. In this case on the surfaces of rain drops. I don't think that charge can be inside the rain drops. I think you need fluids or dust or other objects in air to carry charge.

Maybe I shall try to ask some radio amateur community of today, if they ever had heard about some research on what they experience with electric rain.

The reason for charge build up in thunderstorms is that you have some friction of air to ice krystals or rain drops.

 

[Gymnast]

I used to be a radio amateur (ex G1XRY) and can safely say I have never heard the phrase "electric rain", nor have i experienced my receiver trying to blow it self up during a rainstorm...

Hi dbuckley

I may add, that I neither have heard about "receiver trying to blow it self up during a rainstorm". But I have heard concern.

Did you hear of any other phrase used for interference (noise) during rain?
Did you ever experience special noise during rain?
What frequency range did you use?
Where in the world do you live? (I have a weak idea, that the problem rice near the poles of the globe)

 

[ghostbuster]

Gymnast

Here is a link to a very interesting group (with an interesting antennae flashover motion problem)and cross-linked to a physics chat forum.

http://williamson-labs.com:80/


You may get more constuctive help with your questions at those type of forums

 

[Gymnast]

Charged droplets?

Charged droplets?

Nakulak, thank you for your interesting links.

The use of charged droplets of paint in an electrical field is a very common technique to direct the paint and save paint in an industrial painting process.

I would be more inclined to believe the radio mast is acting as an electric "tether" and stripping electrons out of the air and into the electrical parts. I think that is a far stretch as well, but more probable than charge rain?

If this is the case you should expect the noise on the radio for every rain shower. But you do not - it is only at a few showers.

If you look at this link you have some amateur radio chat (I think):

http://www.eskimo.com/~mwdink/3830/CQWW CW Soapbox Final.txt

Here is my translation of some of the stuf:
"QRN" is a short form for any supposed natural generated noise on radio above normal.
"rain QRN", "rain static" "static crashes" or just "static" is noise on radio associated with rain or snow.

For these guys this phenomena seems just natural...

 

[Gymnast]

Precipitation static

Precipitation static

Finally this evening i found answers. Electric rain do exist, and it is called "Precipitation static". When you make a search on google with this term, you get lots of information.

Electrical charge related to rain droplets is a fact. Damage due to this phenomena is reported by others.

Most concern is the problem related to aeroplanes. In this reference:
http://www.pica.army.mil/e3team/464.pdf

Currents of up to 400 microamps/square meter is reported during flight. I suppose than the current on ground is much less because you dont sweep lots of rain droplets. But it gives an indication the magnitude.

Regarding antennas on earth, I find this link informative:

http://www.jrc.co.uk/publications/library/TM/TM37-1977CoronaDischarge.doc

 

[dtiller]

I have personal experience with this sort of effect. At that time my car was nicknamed 'Sputnik' due to all the antennas sprouting from it. I was driving my car in a snowstorm and the humidity was very low. I grabbed the microphone for a particular radio and got a powerful static shock. Apparently the snowflakes rubbing against the antenna charged the innards of the radio to quite a high static potential. Leaving the mic touching bare metal prevented further zaps since the charge bled off and equalized wrt the chassis.

Here's a google search returning Several Articles about raindrop charge, and lots of articles on how to measure the charge yourself.