Timeline for Weather on a Flat, Infinite Sea
Current License: CC BY-SA 4.0
22 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 8 at 6:22 | comment | added | Ash | @N.Virgo I think an answer from you would be quite valuable. That's the thing though the sunlight intensity is the same as the tropics but the "day" at any given spot is going to be drastically shorter as the sun shoots across the heavens at a ground speed that is the better part of Mach 11,000. | |
| Jul 7 at 11:37 | comment | added | N. Virgo | @Ash ah ok. Total output about equal to a tropical day on Earth. Supposing that the light has a similar spectrum to the sun and that the space above is cold, that means the weather will have about the same total energy input as a tropical summer. This is because the energy source for ordinary weather mostly is the differing radiant effects at different levels, so you can't ignore it if you're interested in the energy budget. On the other hand, there will be no jet streams or trade winds, as you do need horizontal gradients (and Coriolis forces) for those. I should probably write an answer. | |
| Jul 7 at 9:05 | comment | added | Ash | @N.Virgo The OP did state he wanted to use a source with same output as the sun. I'm more concerned with total energy budget than radiant effects on different levels of the atmosphere/ocean. That is affected by the rate of motion, I started thinking of this as the equator at equinox but on fast forward; it's more like the arctic circle at midwinter, the sun skimming past too fast to warm anything before it's gone again. Atmospheric scattering is going to make the flat plain an optically curved surface with a limit on light penetration and visibility regardless of local apparent transparency. | |
| Jul 7 at 3:11 | comment | added | N. Virgo | (Source: I was a scientist doing research on atmospheric dynamics for about 1.5 years before moving on to other fields.) | |
| Jul 7 at 3:03 | comment | added | N. Virgo | Obviously it depends on the properties of the light source and the space it's in, but since this is an invented world those can be anything. If the light provides a lot of energy in short IR/visible wavelengths but almost none in the long IR wavelengths (thus allowing those to radiate away at the top of the atmosphere even when the light is heating the ground) then you can pump about as much energy into the system as you want, regardless of day length. | |
| Jul 7 at 2:53 | comment | added | N. Virgo | @Ash the rate of motion of the sun is completely irrelevant to the build up of a vertical temperature gradient. It could shine all day every day and it would still happen. What matters is that the surface is being heated by shorter wavelengths that travel through the atmosphere and heat the ground while the upper atmosphere is being cooled by the emission of longer wavelengths to which the atmosphere is opaque. These two things can happen at the same time, and when the Sun is shining on Earth they do happen at the same time. Cooling happens continuously, not just at night. | |
| Jul 7 at 1:49 | comment | added | Ash | @N.Virgo The rate of motion of the "sun" is such that you have minutes of reasonably direct daylight at any given location, seconds of peak intensity, followed by hours of darkness and cooling, there's no time to build up heat anywhere in the system. That kind of circulation takes gigajoules of energy absorption in a relatively (geographically speaking) small space to get started and maintain, megajoules per square metre, at tropical intensity ~1500W, this place is getting, maybe, a few tens of kilojoules per metre. | |
| Jul 6 at 18:53 | comment | added | fectin | If you have a 1AU-square flat plane, you WILL have temperature differences across it. Large ones. | |
| Jul 6 at 10:15 | comment | added | N. Virgo | In other words, most of the energy budget for Earth's weather is driven by vertical gradients, not horizontal ones. The horizontal ones will be absent here, but the vertical ones will still be present and can still drive cycling. Horizontal gradients can be created from vertical ones by spontaneous symmetry breaking, e.g. the formation of convection cells. | |
| Jul 6 at 10:12 | comment | added | N. Virgo | @Ash I'm assuming you still have radiation from the top of the atmosphere into space. The atmosphere is transparent, so you will still have that the sun heats the surface more than the atmosphere, which drives atmospheric cycling, which drives the water cycle, because when air rises it causes precipitation, acting as a dehumidifier. None of this requires a daily cycle or any kind of spatial hererogeieity, it only requires that the average EM spectrum of the sky deviates from a black body spectrum, e.g. the light source provides lots of near infra-red but little far-infrared. | |
| Jul 6 at 10:07 | history | edited | Ash | CC BY-SA 4.0 |
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| Jul 6 at 10:01 | comment | added | Ash | @N.Virgo Not with that little time to get the temperature of the surface water up, there will be two terminator sweeps in a matter of seconds, the solar intensity isn't high enough to create a meaningful energy budget.. | |
| Jul 6 at 9:08 | comment | added | N. Virgo | This is not necessarily true, as you will still have thermohaline circulation driven by evaporation. Or you will if the land mass is of significant size I guess. If it's not then the rain will all fall back on the ocean surface and cancel out the evaporation, so you won't get much in the way of circulation I guess. | |
| Jul 6 at 7:59 | vote | accept | Danvad | ||
| Jul 6 at 1:37 | comment | added | Loren Pechtel | @Danvad There are no drivers of big weather in this situation, you won't get big weather. Weather is driven by differences and you have a huge pile of same. | |
| Jul 5 at 19:43 | comment | added | Danvad | K. I was hoping for some weather, so what if the daylight region is only the size of the earth, one comes every 12 hours, but there is more than one? | |
| Jul 5 at 16:46 | comment | added | nasch | The line/zone would be moving at 8.3 million miles per hour! | |
| Jul 5 at 3:23 | comment | added | Ash | @elemtilas So a very fast moving line, there will be very little weather whatsoever. | |
| Jul 5 at 3:16 | comment | added | elemtilas | A pretty fat line! We've only got 12 hours to fill 100 million miles worth of sky with light and warmth! | |
| Jul 5 at 2:36 | comment | added | Ash | @elemtilas There is "daylight radiation" that sweeps across the sea the subsolar "point" may in fact be a line across the whole plain but it does come and go and therefore must have a peak energy input intensity. | |
| Jul 5 at 2:16 | comment | added | elemtilas | I don't think there's a subsolar point, on account of there being no Sun. | |
| Jul 5 at 1:03 | history | answered | Ash | CC BY-SA 4.0 |