My planet is more or less Earthlike, except with no axial tilt and with two disconnected oceans, one at each pole. Each ocean is about 17% of the planet's surface area and roughly circular. How would this affect the planet's climate and weather? Would the equator be incredibly dry and would there be large temperature swings?
4
-
$\begingroup$ "Each ocean is about 17% of the planet's surface area" means that the oceans extend from about 41° latitude north and south to the poles. For reference, that is about the latitude of Denver, Indianapolis, New York City, Madrid, Rome, or Istanbul. $\endgroup$– AlexPCommented Mar 15 at 21:14
-
1$\begingroup$ VTC:Violates the Book Rule. This simple question requires a massive (massive!) answer to legitimately be a best answer. Otherwise it'll lead to many simple answers that each focus on a small part of the whole. Frankly, nobody knows to a science-based degree what such a planet would be like because we have only one data point to work with: Earth. A science-fiction question would let us speculate, but you must still focus on one small issue at a time with mulitiple questions. $\endgroup$– JBHCommented Mar 16 at 0:38
-
1$\begingroup$ give me a reason the ocean haven't frozen already then depends on our mood maybe we will humor you... or is it humor me? $\endgroup$– user6760Commented Mar 16 at 2:10
-
$\begingroup$ It's an interesting hypotetical question in my opinion. But I think it's hardly possible for a planet to develop a continuos landmass all around the globe. Plate tectonics don't work that way. May be possible though if the planet is in such conditions that surface is losing water (either venting to space or getting trapped underground / at the poles), something like Mars. $\endgroup$– Duncan DrakeCommented Mar 18 at 10:29
Add a comment
|
2 Answers
$\begingroup$
$\endgroup$
3
We can make a reasonable guess at what the winds may do.
The tropics of Earth are bounded by two rings of Hadley cell convective flow. Hot air rises at the equator and falls off at a latitude of about 30 degrees. The cells are not fixed in position or strength - they move with the seasons, and the cell over the equator is the strongest one. The rising convection will be over land, so the whole circulation will probably be dry.
Around the poles, there are polar cells. These are fairly fixed convective cells. The North Pole is ocean, so this can represent what happens in your planet. The winds are clod and do not pick up much moisture. The poles are mostly dry.
Between the two, there is a mid-latitude convective cell. If this was fixed, we might expect the moist air from over the sea to heat up and rise, which may generate clouds but possibly no rain. However, the mid-latitudes are much less of a fixed thing than the Polar and the Hadley cells. This is where we get cyclones and anticyclones. It is sometimes termed the 'zone of mixing'. If 17% of the surface gets us up to 40 degrees latitude ( thanks @AlexP ) you could base your model on the top half of Portugal or Spain. The prevailing winds will come off the Atlantic, so they will have a similar moisture content to the weather at the edge of your planet. Hot summers with less winds, as you approach (but do not quite get into) the Hadley cell with its descending tropical air. Winter may have rain and cyclonic storms.
One more exotic twist - you probably have a von Kerman boundary at the edge of the polar cell that sheds the cyclonic storms. If you managed to fit an exact number of cycles in a von Kerman vortex street around your poles, you might have a stable hexagon like Saturn, or some other shape. The Earth does not have a good integer fit, and it has seasons, but if you had no seasons, a fixed storm pattern might be stable. The storms would move around the planet but they would not change.
-
$\begingroup$ Thank you for your well thought out answer! I’m about to mark it correct— although you mentioned hot summers and wet winters, and my planet has little to no axial tilt. Could you edit to cover what that median state would be? $\endgroup$– SnorkaCommented Mar 17 at 12:00
-
$\begingroup$ Poop. I missed that. This may make the range of the zone of mixing narrower, as the Hadley cells should be pretty stable. However, you should still get cyclones and anticyclones. $\endgroup$ Commented Mar 18 at 12:17
-
$\begingroup$ Note that Earth has a very small ocean at the north pole, extending only to about 70° latitude. The oceans in this question extend to about 41° latitude! The situation is very different. $\endgroup$– AlexPCommented Mar 19 at 11:38
$\begingroup$
$\endgroup$
5
Dry, very dry.. the most heat hits the equatorial regions, evaporating the water - and it rains down at the relatively cool poles, were most of it freezes up into gigantic glaciers over time.
Its basically a more temperate version of https://homeworld.fandom.com/wiki/Kharak ? The weather will be basically just bands of nearly undisturbed air, giving away little moisture.
The only way you could transport water down to the equators would be heating the polar oceans somehow- and then the moisture raining down beyond a watershed via https://en.wikipedia.org/wiki/Rain_shadow so that the river flows downwards towards the equatorial desserts in large rivers..
Geothermal rifts could heat the polar oceans..
-
1$\begingroup$ On Earth, the polar regions see very little precipitation. Could you show on what basis you believe that in the world described in the question the poles would receive a lot of precipitation? (And the oceans described in the question are not "polar" by any definition. The northern ocean would extend south to about the latitude of Rome or Istanbul...) $\endgroup$– AlexPCommented Mar 15 at 21:20
-
1$\begingroup$ Same mechanism that collects water into glaciers on our arctic regions. You don't need much, but if nearly none escapes, that water bunches up during cooler periods, eventually resulting in a sort of en.wikipedia.org/wiki/Snowball_Earth similar to a filter $\endgroup$– PicaCommented Mar 15 at 21:51
-
$\begingroup$ Reason being you have a continental climate with extrema and no oceans to evaporate most of the moisture in the hot zones. esri.com/arcgis-blog/products/arcgis-online/mapping/… $\endgroup$– PicaCommented Mar 15 at 21:53
-
1$\begingroup$ Being very dry on most of the landmass seems most likely. But it's really complicated. I found this article about simulation of atmospheric flows on terrestrial planets. gmd.copernicus.org/articles/16/5601/2023 $\endgroup$ Commented Mar 18 at 10:32
-
$\begingroup$ @Duncan Dake: Wow, yes it is really complicated. Ive basically assumed it to be earth like. Different humidity, Co2 levels, i did not take that that into account. A hothouse planet would propably have a completely different weather, with torrents of rains everywhere, every day.. $\endgroup$– PicaCommented Mar 18 at 10:36