Condensation Nuclei, the Seeding of Clouds, and a Reason For Unrest in China
Hey Mom?
What are condensation nuclei?
Thank you,
Conversation New To I
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Hullo Convo,
You must have seen condensation nuclei referred to in the answer to the question about contrails. Here’s the skinny: When the air temperature reaches it’s dew point, otherwise known as the temperature where it becomes saturated and can no longer hold any more water vapor, that water vapor condenses. Condensation is the name we give to the process where water vapor becomes liquid and thereby visible to the naked eye. Voila, we have a cloud! Well, usually. Actually, it’s not quite that simple. So where do condensation nuclei come in? Well, the explanation I gave left out the simple fact that without some extremely small particles for that water vapor to coalesce around -solid or liquid will do- nothing happens. That’s right. Without those itty bitty bits of dust, clay, sea salt, soot, sulfate etc, condensation won’t occur. Even at the dew point. In the absence of this fine particulate, the air would actually have to achieve 400% saturation before the first drop would condense. Not a typo. 400% saturation.
Most times in most places, we have plenty of particulates. In fact, you could say we have a plethora of particulates! Air pollution is a pretty pernicious problem, people. However, if the reason it isn’t raining is suspected to be a lack of condensation nuclei, why not add a few of our own? Thus was born the notion of cloud seeding. Did you know that in China, there’s actually strife between regions who feel that one “stole the other’s rain” by being the first in the area to fire silver iodide into the sky? I kid you not. I couldn’t make this stuff up if I tried.
Now be good, and quit fighting over who gets to play with the rocket launcher next!
Mom
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