The only stable place for a space sun shade is the L1 Lagrange point, and that’s too far. At that distance, the penumbral shadow covers the whole Earth. So it reduces sunlight to all parts of the Earth at the same rate. There’s no way to cool down a specific part of the ocean.
You could also have a set of lower-orbiting sunshades, and make them louvered. When it’s over the area to be cooled, you close the blinds, and when it’s over some other area, you open them.
Or put it in a geosynchronous orbit, so it always stays over the ocean you want to cool. It won’t always be between the Earth and the Sun, but when it isn’t, it’s nighttime anyway, so it doesn’t matter.
This would only block the sun for a few seconds at noon.
Because this thread needs this for completeness: The NOAA’s page on the use of nuclear weapons to dispel hurricanes. The whole thing can be summed up in one particular sentence:
I suppose an alternative would be to relocate a large number of homosexuals to Bermuda. I’m told they attract hurricanes, therefore a sufficiently high concentration should divert any such storms away from the East Coast.
I think Chronos is implying a baffle 2,000 km x 12,000 km … something that could block the sun for a half day or so … we could use all the fake moon rocks we already have in LEO …
Back in the 1970’s and early 80’s, when I was studying environmental science, there were some half-baked ideas floating around to do a variety of things about our environment – fortunately, better minds prevailed regarding most of them. stopping hurricanes may be one of the worst of them (but yeah, this idea does go back a ways). The problem is that hurricanes are one of the larger mechanisms for transporting heat from equatorial climes towards the cooler northern latitudes. One major worry that existed, that kind of killed the idea is that if you interfere that natural flow of energy, you are going to end up with an even greater temperature gradient, which could result in even bigger storms in the long run and other unforeseeable consequences. It’s kind of like what happened with the US forestry service – they went out and interfered with the natural seasonal brush fires, which allowed brush to overgrow, our forests, which lead to the small seasonal brushfires being replaced by huge conflagrations.
This question was picked up for a column by Cecil!