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NASA Confirms Rainy Cities
Devil's BSD writes: "It's true, urban areas are rainier than rural areas. Using the Tropical Rainfall Measuring Mission satelite to measure rainfall around cities, NASA found that areas downwind from cities had up to 116% more precipitation than those upwind from it. The cause? The major heat difference, up to about 10 degrees Fahrenheit (5.6 Celsius degrees), caused by the asphalt and concrete in cities. This story is posted on the Goddard Space Flight Center page."
( Pardon the pun ).
This has been known for some time. The claim, when I heard it, was that particulate matter in the air from exhaust etc gave the water vapor something to coallese onto and hence form water droplets. I think particulate matter is more reasonable to expect than temputure variations ( even tho these do exist ).
Why is Nasa re-inventing what is already known? This was out about 5 years ago ( or longer - memory rentention tends to blur ).
There's a gorilla from Manilla whose a fella that stinks of vanilla and has salmonella.
So if the change of temperature was only caused by the body of water, the whole river would cause rain down-wind (this is probably true, but is an orthogonal problem).
Claiming that the observed effects can be explained by the rivers would imply that those river do not exist outside of the city...
I'm no meteorologist, but it seems to me that there's a world of difference between conditions that produce clouds and conditions that cause clouds to precipitate out. Rising warm air may build a cloud, but without a coincident drop in temperature or air pressure, I don't see how that could translate to more rain in the cities. In fact, I'd suspect the heat island would reduce rain in the cities and increase rain outside of the cities.
Their model seems primarily to be: we noticed that this condition exists and this other condition exists too; perhaps through some mysterious not-precisely-known interaction of the one is causing the other.
The fact that rainfall is presumably (I'm not sure the observation is meaningful without comparative historical data) greater in the cities as well as downwind from the cities suggests another causative factor to me. The already posited airborn particulate output of cities seems to be a much stronger explanation in my opinion.
Let's move all our farms to cities...
In much of the United States, the Corps of Engineers builds dams on local streams to create lakes for recreation and water supply. For instance, look at this satellite image of Dallas. All those lakes are artificial and are made from tiny, even intermittent Texas streams, very much unlike the rivers found elsewhere. So, in a sense, there are bodies of water that exist only in the vicinity of cities in this part of the world. If they affect weather, that is more than I know.
No references of course, this is slashdot, but I read sometime in the past year or two of studies that confirmed the weekend effect. Maybe Nature or Science, forget by now.
Infuriate left and right
That way, they'll get more rain without the bother of having to pack them up and move them.
"Those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded."