I've had this idea for a civilization existing completely under a dome. This would include their great city, an island roughly the size of Texas, and a fair stretch of ocean surrounding it. I'd like for apparently natural weather patterns to continue, including cloud formation and precipitation. Realistically, how high would this dome have to go for that? To clarify, there is an AI regulating everything from the temperature of the ocean to the energy output of an artificial sun embedded in the dome. This allows it to control the weather; it can even electrically charge the air if it's in a stormy mood. But like I said, I'm just not sure how big the dome needs to be for there to actually be any weather.
Depends. Will people be flying around in planes or handgliders? How tall will the tallest buildings be? Are there any large mountains on your island? I would suggest the dome be at least a few thounsand feet taller than the highest point of land.
It's a long story, but the people living in the dome are not advanced at all. So there's no flying in there. The tallest building is two hundred meters at most, and there are mountains. I can do a couple thousand feet. Might be a bit tricky, since this island is supposed to be anchored at the bottom of an ocean. Maximum submarine depths are classified, so it'll have to be a guess at what's deep enough so that those things don't smash into it.
If you are having a highly advanced technological system controlling weather then I don't think you need to be concerned with the height of the dome for the sake of weather. The system could change air pressure and temperature, so you wouldn't need to change elevation for those things to occur. I think you should be aware, however, that a dome is going to leave the very edges unaffected by weather--the clouds for rain, for example, would collect at the top of the dome and the sloping sides would mean that there will be a ring around your island that doesn't get rain. Unless your "dome" is actually straight-sided for a good span of height before it actually takes on a dome shape this could be an issue if you want your weather to span the entire island.
That big, here would likely be some weather, IMHO. I don't know about big weather systems though. There should be thermals though, and moisture would travel from one end to the other as the sun moved. Another question you should be asking yourself is "If it can, would it?" It's possible that a big dome normally would (though I don't know), but that it has been designed specifically NOT to. No big storms means no dangerous stuff, like lightning, landslides, etc. -Frank
I don't think that'll be a problem. The dome is huge and at a shallow curve, and the island is relatively near the top and center. The majority of clouds would form over the island from the sound of it, but at such a gentle slope, they should be seen over much of the sky. There's several times as much open seawater as land; if the island is a foot long, then there's a foot of water in every direction around it. So triple the diameter of Texas... That's one big bubble. Sounds like rain all across the island is possible. FrankABlissett: On its own, no, there probably wouldn't be any severe weather. But there is an AI manipulating things behind the scenes, changing temperatures and such. With enough meddling, I'm sure it could create some kind of storm.
Assuming the island is (roughly) round, that would make the area under the dome four times that of the land - or, 1 part land, 3 parts water. Just looked up the area of Texas - ~270K square miles, ~700K square km. Texas is ~780 miles wide, or 1250 km. The area under the dome, as noted, would be four times that, if the linear distance was double. A couple thoughts. Is the marine system open to the rest of the world-ocean? If not, how would that affect the marine hydrology - ie currants, tides, etc? Are the residents capable of getting to the dome via boats? If they are not, do they even know it exists? If they can, but barely, has a sea-based culture developed there, largely cut off from the rest of the population? Just some ideas to get your noggin knockin'. -Frank
Yeah, I kinda think that my "size of Texas" decision is a little much. That would take up a gigantic chunk of any ocean I put it in. It just seems appropriate, because it needs to be large enough to have supported multiple kingdoms in the past. Even though they're rhetorical idea generators, I can answer all of those questions with certainty. I've put a great deal of thought into this place, and its basic history is set. I just wasn't sure if it was a scientifically sound idea. I appreciate that you're willing to help, though. All of you.
The Vehicle Assembly Building for the Apollo space program had its own weather. Clouds would form, and at times it would even rain. But it all depends on what you mean by "normal" weather patterns. If you are talking about coriolis storms like hurricanes and monsoons, the dome would need to be continental in size. Many weather systems depend upon global circulation patterns like the Jet Stream, or upon large scale geographic features (consider lake effect snowstorms in western upstate New York, or New England's ocean-effect Nor'easters).
