Cecil has refused to answer my question. What ever happened to cloud seeding?
I heard that they are expecting a new multi-year drought in California. Can’t we use cloud seeding to bring on the rain? Or to “dump” water out of clouds that are headed for already deluged area?
Now one obvious answer is that it isn’t that easy to do. If it were easy and efe3ctive, it would be done. Still, I remember shows and even cartoons that mentioned cloud seeding since I was 7 (Tennesse Tuxedo on WOC (now WKQC), Davenport Iowa, Sunday Morning in the '70s mentioned it.)
To produce rain via cloud seeding the atmosphere has to have enough moisture to adhere to the chemical dust and form drops of moisture big enough to fall to the ground.
Most of the duluged areas are that way, because a cold air mass hits a warm air mass. When the warm air cools it becomes saturated to the point where it can’t hold the water. You then get the drenching rains. Thats why you have deserts on the other side of the Rockies. The ocean air from goes over the Rockies climbing higher and getting cooler.The atomosphere dumps it’s moisture before the it gets accross the mountains.
We had a wet cold summer for most of the year in Wisconsin, while the south had their dry heat wave. We were where the hot air hit the cold air. The lowering of the air temperature does a lot more to make rain than adding additional nucleation points in the clouds to form water drops.
Heh, that rimshot is still ringing in my ears, samclem.
Here’s a short blurb on weather modification in CA. It notes that cloud seeding works best in normal-rainfall years, presumably when it isn’t needed so much.
I did this search at google.com: “‘cloud seeding’ +.gov regulations” and came up with about 80 hits. My spider sense is tickling right now, because normally if the EPA regulates something, it generates a whole lot more chaff than that.
A warning, threemae: the best way to make sure the EPA does regulate something is to ask them whether they do or not.
My gut tells me that this matter is probably regulated by the state environmental protection arms right now, and are covered federally under some less-specific statute. That may mean that rules will vary wildly from state to state, with California having a branch chief devoted to the practice and other states having a referral number to a full answering machine that hasn’t been checked since 1982. Good luck.
You asked where I heard that there may be a multi-year drought starting again in CA. I’m a bit foggy on where I first heard it. I think it was broadcast on NPR, which is almost the only source of news I pay attention to. It was quite a few weeks back.
A good source for this type of info is a the annual Old Farmers Almanac. They’ve kept track of weather patterns for over 200 years and they’re pretty accurate about predicting general weather trends over the course of a season.
I believe it was 1972 when Rapid City, South Dakota experienced a terrible flood. Some clouds were seeded and then they did not move as expected and it rained and rained in a valley from which the water could not drain rapidly enough so the flood was triggered. Incidents such as that may have something to do with why we don’t hear much about cloud seeding any more.
I’ve read (in John McPhee’s “The Control of Nature”, IIRC) that cloud seeding was used in Southern California back in the 70s/80s – there were several mortars placed in the San Gabriel mountains that shot silver iodide into appropriate clouds. However, this approach apparently worked a bit too well; too much rain came down, resulting in mudslides and debris flows.
I lived in SoCal during the last drought – I remember Santa Barbara spending something like $40 million building a desalination plant in the early 90s. IIRC, they ran it for a few weeks in the spring of '92 then mothballed it for future droughts. In the meantime, I believe the locals voted to hook into the California Aqueduct system, which more or less makes their desalination plant obsolete and will cost much more than $40 million. Of course, everyone in Santa Barbara is filthy rich and can well afford the increased taxes. :rolleyes:
Interesting coincidence – I also lived in the Quad Cities (specifically Bettendorf) in that era, and spent many a Sunday morning watching Bullwinkle, Underdog, et al.
Kept track of weather patterns in California for over 200 years? The National Weather Bureau would like to talk to them, I’m sure.
Considering that, for the first 100+ years of their existance, they could only keep track of weather patterns around the US Northeast, how would that help anyone predict weather in the rest of the US?
And, upon what do you base your statement “they’re pretty accurate about predicting general weather trends over the course of a season”. Can you back this up?
Actually, Vincent J. Schaefer, a colleague of Bernard Vonnegut, actually invented cloud seeding. Vonnegut improved upon the method by using iodine crystals.
But, Holy schnikes! , look at this picture of Bernard. It looks like Kurt in a few years(or perhaps now).