What effect does smoke have on rain?

[JonathanBelles]

I would think that it would dry the atmosphere out and not allow it to rain. Rain is now moving towards my area. Will it fall apart? If smoke is heavy enough and conditions are right, could smoke produce rain? that last question is probably a stupid one.

[Matt-hurricanewatcher]

I believe that raindrops form on salt and dust in the Atmopshere. But if theres to much of it then it makes to many nuci, which doe's not allow for the raindrop to grow to the size it needs to fall.

[tropicana]

I found this on the net from a science website i was just browsing...

How smoke keeps the home fires burning.
A raging forest fire is one of nature's most uncontrollable forces. And it's not just because it spreads so easily. According to new research, the smoke from a fire actually keeps rain from falling and putting it out.

The evidence comes from a high-tech NASA satellite. According to cloud physicist Daniel Rosenfeld of Hebrew University in Jerusalem, it's shown that smoky clouds produce far less rain than their smoke-free counterparts nearby.

Rosenfeld:
"It has been suspected for many years, but this is the first time that we have the means with the new tropical rainfall formation satellite to actually measure and prove it."

He says rain normally happens when the water droplets in a cloud clump together and fall to the ground. But when smoke particles get into a cloud, they attract water too. As a result, the water gets spread too thinly, and the drops never get heavy enough to fall.

Now the researchers are wondering if particles of pollution have the same effect.

Rosenfeld:
"And we have some evidence towards that, over Manila, for example. Which is a huge city which is notorious for being very polluted."

Since rain is so critical to human life, he says it's important to know if our own activities are keeping it away.

-justin-

[Aslkahuna]

Actually, the first indications that this was so came from the GROMET II Drought Alleviation Cloud Seeding project in the Philippines in the 1970's where they found that smoke from the canefield fires resulted in less efficient rain producing clouds.
A study done over the Indian Ocean has found that smoky pollution from Asia has had a delterious effect on rainfall there.

Steve