Polar Heat, Equatorial Cold - Climatic Effects of Inverted Global Temperatures

Question

How does inverting global temperatures affect climate? Here exists a fantasy world similar to earth in all important ways. Except, however, that global temperatures have been flipped; it is coldest at the equator and warmest at the [geographic] poles.

After reading Climate Modelling 101, though I understand the basics, I am very much ignorant. Would there be any unexpected consequences from inverting temperatures? Obviously, one could simply flip the logic of the aforementioned blog around. But I suspect there may be more to it, as things like the effect of sea ice on climate are not discussed.

What are the climatic effects of inverted global temperatures? Especially those which cannot be extrapolated from the blog. Please explain giving scientific context.

REGARDING SPACE: There's an unknown phenomenon beyond the planet's atmosphere, existing like a ring around the equator. This phenomenon allows some visible light to pass through, but deflects non-visible light from the equator, channelling it towards the poles. Most of the sun's energy enters the atmosphere at the poles and then behaves normally. Under the planet's atmosphere no unusual phenomenon exist.

REGARDING LIGHT: The light which reaches the equator is cold. Visible light carries 42% of solar energy to earth. The phenomenon thus bends non-visible light, and some visible light, towards the poles.

P.S. Apologies for those who have answered musing about planetary tilt; my fault for initial incompleteness. Questions are hard. I'm interested in what happens to the climate, NOT about anything that may justify how the poles are warm and equator cold. The scientific part is about unexpected climactic effects in this hypothetical.

Answer 1

There are 2 major differences I see here as far as how the earth now receives its light.

1. More concentrated / smaller area. The land areas that the sun hits around the globe is significantly larger than the area of just the poles. So same energy over less area means the warming will be more intense at the poles.

2. Land! This works best if you've got an actual globe as the 2-d perception is a bit harder...but if you take a globe and spin it around per normal, you will see a lot of water, particularly in the southern hemisphere. Now view your globe from the north pole or south pole...you will notice there is a significantly larger amount of land around the poles than the vast oceans around the equator. Oceans tend to fully absorb sunlight while land will reflect more...even though your planet will get the same amount of light, more will be reflected.

Major changes from this:

You will have a cooler globe on average, simply because the land mass reflects more sunlight than oceans...which makes sense in this world as the arctic region is now the giant equatorial band and not a simple pole.

Thermohaline circulation, the flow of energy across the oceans, is likely greatly impacted by this and as such the existing system likely wouldn't exist. Ultimately a smaller area of water is being warmed in this setup, however the warming should be more intense. This means a greater intensity (more energy) will be driving whichever process is moving the energy around the oceans. I'd actually suggest that due to this, a complete frozen equator is unlikely as ocean currents should keep some lines open. Interesting story point if an equatorial ship passage existed, and I'd say it's plausible with the right currents. Equatorial land would be frozen over.

Wind! Similiar idea as above, except in the air. Wind currents should be more intense as it has a smaller area being warmed more intensely, and that should drive wind patterns much stronger. Hard to speculate much more on that, I'd imagine the Polar Jet would be more equatorial and the sort, if that even happens.

There might be a simplification of weather to some degree...sun hits pole, water evaporates, forms clouds, moves towards equator, hits cold air and snows, repeat...air from the poles doesn't exactly have much place to go.

The Arctic has land that will prevent the formation of it...but there is a good chance the antarctic continent will develop a strong ring of wind around it that is always present just like a jet stream.

Answer 2

Not sure why the premise is getting so much pushback. Is it so unbelievable?

The equator is hot because it gets more direct sun. If the earth were tipped such that the poles faced the sun, the poles would get more sun. And be hot.

From Quora:

From Universe Today:

While the rest of the planets in the Solar System can be thought of like spinning tops, Uranus is more like a rolling ball going around the Sun. During the point of the Uranian solstices, one pole faces the Sun continuously, while the other pole faces away. Only a thin strip of the surface of Uranus experiences any kind of night/day cycle. Uranus’ poles experience 42 years of continuous sunlight, and then 42 years of continuous darkness. During the time of the equinox on Uranus, the planet’s equator is facing the Sun, and so it experiences day/night cycles like we have here on Earth.

So there's your toasty poles. Uranus-style. One warm per season, true. I wonder if you could give the sphere another axis of rotation to swing the poles around sunside more often...

Re the equator: make it cold by making it high. Latitude and elevation are both ways things get colder on earth. Squash the planet so the equator rides a high elevation ridge. Ecuador is on the equator. It gets cold.

From here.

Higher is colder.

"Could this happen" is a legit (and pretty cool) question. But that said, the question as I see it now is "what things have I not thought of that would happen if...". I am still learning the rules here but I gather openendedness to that degree is frowned upon.

Answer 3

I think that you would likely have similar weather patterns to Earth except that flows would be in the opposite direction.

Hot air would expand at the poles and head southward. The coriolis effect would tend to twist that downward stream counter to the rotation of the planet. Look at the wind bands of Earth and just do the opposite and then you would have general weather patterns. Unless someone knows better, I imagine that the jet stream would be the same so look at how things could swirl as the prevailing winds get near the jet stream.

Water flows would be different. Water doesn't expand much but it does expand enough that heavier water sinks under warmer water. Sometimes ocean currents return by traveling around the ocean and sometimes they return by simply going back the way they came at a different depth. So, the direction of upper and lower flows would be the opposite but the circular direction should be the same.

Also, if there isn't a landmass covering a pole, it probably has a permanent hurricane. If there is a landmass it probably has a central desert that gets almost no rain in a decade (the moist air would tend to circulate around the center). As it is, Antarctica has one of the driest deserts because of this effect.

Answer 4

This is perhaps not quite possible, but is certainly good enough for fantasy or science-fantasy, or even just soft sci-fi.

Put a moon in a fairly close orbit. This moon has a lot of activity, whether this is from cryovolcanos, from classic volcanic activity or something else.

The moon is small enough that violently ejected material regularly escapes from its atmosphere, which forms into a diffuse ring along its orbit, which roughly aligns with the planet's equator. This ring of material blocks a substantial amount of solar radiation, which more than offsets the normal difference in the heat available from the sun between the poles and equator.

This planet is a bit closer to its sun than the earth is, so that the poles are actually quite warm, and the equator would likely be a sunbaked hellscape if the cloudring did not exist.

Answer 5

Its not a bad question but as @AlexP mentions, there is no scientifically accurate method to get you what you want.

Simply put the sun is the dominant force on climate. No matter the make up of your atmosphere or the amount of volcanic activity you just can't overcome the overwhelming power of the sun.

To have the temperatures flipped on a planet simply isn't plausible.

This XKCD what if entry is relevant. It discusses the sun's impact in relation to gravity rather than temperature but conceptually it gives a good idea of the scale you are working with.

This article from NASA may also be helpful.

Of course this is all assuming an earth-like world...there are some weird situations that could get you closer, but no matter what the poles can only be evenly heated at low temps...though hypothetically you could get a hot one and a cold one...in a definitely non-earth-like setup.

Answer 6

Imagine this, a planet with no axial tilt, close enough to the sun that the poles are nice and toasty. The equator would normally be blisteringly hot, but there is something blocking the sunlight, fully or partially, to latitudes around the equator, so it ends up cooler. The further south you go it will still get hotter, until the filtering begins.

So that's a way to get near what is proposed. Presumably the warm air would still still rise, and spread out from there. The equatorial area would be the largest volume of cooling air, so I would expect the bulk of the rising air to move in that direction.

Answer 7

Well, purely from physics, Coriolis https://en.wikipedia.org/wiki/Coriolis_force#Applied_to_the_Earth would still work the same way. You'd still have Hadley cells, but they'd be inverted in direction https://en.wikipedia.org/wiki/Hadley_cell .

That being said, it's much more difficult to talk about climate here because of the massive effect the sun has on climate in an area. Assuming the planet was pointed directly at the sun on its axis, and tidally locked, you'd have one pole hot, the equator having a sharp temperature gradient from dark-light and the other pole frozen. There's basically no orientation where the planet could have hot poles and a cold equator, so it's difficult to give any explanation beyond that. Solar radiation is just that important for climate questions.

Answer 8

If you could achieve this inversion, then a key difference is that there would be two viable zones (of latitude), separated by a wide, likely impassible equatorial zone (ice, blizards, polar-bear equivalent predators, etc.)

So -- except for hardy spores, seeds and the occasional lucky hero -- the two habitable bands may well have separate ecologies (except for air) and their people(s) may have no knowledge of the other zone, except in stories and legends. Possible grist for stories, I'll hope.

Answer 9

I think that it is theoretically possible for a real world to have very similar climate, warm at the poles and cold at the equator. Unfortunately I can't do climate simulations for you but maybe you can find someone who can.

There is speculation that Earth might have been almost completely covered with ice and snow for millions of years hundreds of millions of years ago, so it is theoretically possible for Earth's tropics to have a very cold climate.

The problem is getting the planet's tropics cold at the same time the poles are warm. And my solution will make it impossible for your readers to ignore that the setting is on an alien planet in a different solar system. But fantasy stories can be set on alien planets in outer space just as well as on Earth or on flat worlds or in strange settings that are never explained, that have so much beyond the edges of the maps that the readers don't know if they are on spherical planets or flat discs.

You may have heard about the habitable zone around a star, a zone in which an Earth-like planet, if orbiting there, would receive the right amount of light and radiation from the star to have temperatures necessary for life.

Stars much more massive and brighter than Earth's sun would burn off all their hydrogen fuel much to fast for their planets to become habitable for humans or for intelligent life to evolve. Fortunately, most stars are red dwarf stars that can last for trillions of years. Unfortunately, the habitable zones around dim red dwarf stars are so close to the stars that planets orbiting in them would become tidally locked to their stars.

Their days would equal their years in length. One side of such a planet would always face toward the star, and be in eternal day and heat, and the other side would always face away from the star and be in eternal night and cold. And astrobiologists wondered and calculated whether life would be possible in such a world. So nobody knows if life bearing planets can orbit in the habitable zones of red dwarf stars.

When planets were first detected orbiting other stars, the first ones were very large, often several times the mass of Jupiter, and orbited close to their stars, often close enough to be roasted by the intense heat and light of their stars. Such worlds became known as "hot Jupiters".

And astrobiologists realized that if a "hot Jupiter" orbited in the habitable zone of a dim red dwarf, all its moons, if any, would be tidally locked to the "hot Jupiter" that they orbited and not to the star that the "hot Jupiter" orbited. Thus they would not keep one face always pointed at the star. Instead they would keep one face always pointed at the "hot Jupiter" and would have more more less normal days and nights.

And it is possible that some moons orbiting "hot Jupiters" could be several times as large as the largest moons in our solar systems and thus large enough to be habitable planets and have life. Thus it is possible that planet sized habitable exomoons orbiting "hot Jupiters" that orbit red dwarf stars might be as common as habitable planets orbiting other stars.

And this is important because I don't know what the size of the orbit of my hypothetical planet with warmer poles and colder equator will have to be. It is very possible that it will need to have a much shorter year than Earth and have to orbit very close around a red dwarf star, and then it will have to be a habitable exomoon of a giant planet instead of a habitable planet itself, in order to avoid being tidally locked to its star.

Most planets in our solar system spin with an axis of rotation that is almost perpendicular (at a right angle or 90 degrees) to the plane in which they orbit the sun. The rotational poles of six planets are inclined between 0.0 degrees (Mercury) and 28.8 degrees (Neptune) from such an expected right angle position. And most moons in the solar system have their axis of rotation ninety degrees from their orbital panes.

Thus it is expected that most extra solar planets will rotate around poles that are close to perpendicular to their orbital planes. But there will be some exceptions, like the two planets in our solar system that don't have such rotational poles. Venus rotates with an inclination of 177 degrees, almost exactly backwards from the normal position, and Uranus rotates with an inclination of 97 degrees, thus rotating almost exactly in its orbital plane.

Thus Uranus has very odd seasons in its year of 84.01 Earth years. Not that such odd seasons would matter very much on such a cold gas giant planet and its moons. But they would matter a lot on a planet in the habitable zone that had a axis of rotation inclined a similar amount.

Imagine a habitable planet orbiting in the habitable zone of its star, with an axis of rotation inclined about 90 degrees and thus almost in the plane that the planet orbits its star in.

In season A, the Northern hemisphere might be aimed almost exactly at its star. Thus the northern hemisphere would be in constant daylight and would be heating up all the time, especially the polar regions that would get the light coming almost straight down. The equatorial regions would not get very intense sunlight since it would be coming in very lo almost parallel to the ground, and any elevations would cast very long cold shadows.

The southern hemisphere would be cooling off in constant nighttime. Any people in the constant darkness would be able to watch the stars rotate 360 degrees every full rotation of the planet, unlike the natives of the northern hemisphere.

Season B. The planet is 90 degrees in its orbit from season A. Autumn in the northern hemisphere and spring in the southern hemisphere. Now the equatorial regions would face directly toward the star during the day and directly away during the night. Both the northern and southern hemispheres would also have alternating days and nights. The northern hemisphere would cool off and the southern hemisphere would warm up. Everybody anywhere on the planet could tell time by the position of the sun during the day and the position of stars and constellations during the night.

if the equatorial regions had a high altitudes and thin air and perhaps snow and ice on the ground to reflect light back into space, they might not warm up very much during that period.

Season C. 180 degrees of orbit from season A. The exact opposite of Season A. Northern hemisphere winter and constant night, and southern hemisphere summer and constant day. The equatorial regions get light at very low angles that doesn't heat them up very much, this time coming from the southern side and not the northern side.

Season D. 270 degrees of orbit from season A. The exact opposite of season B. spring in the warming northern hemisphere and autumn in the cooling southern hemisphere.

Now the equatorial regions would face directly toward the star during the day and directly away during the night. Both the northern and southern hemispheres would also have alternating days and nights. The northern hemisphere would warm up and the southern hemisphere would cool down. Everybody anywhere on the planet could tell time by the position of the sun during the day and the position of stars and constellations during the night.

And there might be intermediate seasons of change. Season AB between A and B, Season BC between B and C, Season CD between C and D, and season DA between D and A. During those seasons every part of the planet would get at least a little daytime and at least a little nighttime.

If the planet orbited around a fairly large and bright star like the Sun, each of the eight seasons might last for at least one Earth month.

But if the planet's year lasts as long as a Martian year of 1.88 Earth years, or an Earth year, or even a Venusian year of 0.62 Earth years, the summers at the poles might get too hot, and the winters at the poles might get too cold. You seem to want both poles to stay warmer than the equator all year round.

The polar temperature extremes can be moderated by ocean currents and winds carrying heat from warmer regions to cooler regions. But on Earth that is not enough to prevent many regions from having large temperature swings during the different seasons.

Thus the eight suggested seasons on that planet should be very short to prevent extreme temperature rises and falls at the poles. I guess that each season might last about two to four days of the planet, making each year last for about sixteen to thirty two days of the planet.

And with such a short orbit the planet will need to be an exomoon orbiting a hot, or at least warm, Jupiter-like planet. If it is a lone planet the tidal forces from the nearby star will gradually change its axis of rotation until it is almost at a perpendicular 90 degree angle to the planet's orbital plane. And it will slow down the planets rotation until the planet's day is the same length as its year, and then lock the rotation period. This will take mere millions of years early in the planet's history long before the first single celled life forms develop.

Unless the planet is an exomoon and will be tidally locked and protected from the star's tides by the planet it orbits - and thus keeps it odd axis of rotation until intelligent life develops, just as the moons of Uranus are locked into Uranus's axial tilt.

The article "Exomoon Habitability Constrained by Illumination and Tidal Heating" discusses the factors that affect the habitability of hypothetical exomoons.

The longest possible length of a satellite's day compatible with Hill stability has been shown to be about Pp/9, Pp being the planet's orbital period about the star (Kipping, 2009a).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3549631/1

Thus it is believed that the year of the planet and its habitable exomoon as they orbit their star will have to be at least nine times as long as the exomoon's day and month (or day/month. Since I suggested that the exomoon may have eight seasons, if they are equally long they will each last at least 1.125 of the exomoon's day/months.

Another possible advantage of an exomoon with a Uranus like inclination of its rotational axis is that tidal heating of an exomoon can keep a pole region warm during its long winter.

On the other hand, we can imagine scenarios where a moon becomes habitable only because of tidal heating. If the host planet has an obliquity similar to that of Uranus, then one polar region will not be illuminated for half the orbit around the star. Moderate tidal heating of some tens of watts per square meter might be just adequate to prevent the atmosphere from freezing out. Or if the planet and its moon orbit their host star somewhat beyond the outer edge of the IHZ, then tidal heating might be necessary to make the moon habitable in the first place. Tidal heating could also drive long-lived plate tectonics, thereby enhancing the moon's habitability (Jackson et al., 2008). An example is given by Jupiter's moon Europa, where insolation is weak but tides provide enough heat to sustain a subsurface ocean of liquid water (Greenberg et al., 1998; Schmidt et al., 2011). On the downside, too much tidal heating can render the body uninhabitable due to enhanced volcanic activity, as it is observed on Io.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3549631/1

The synchronized rotation periods of putative Earth-mass exomoons around giant planets could be in the same range as the orbital periods of the Galilean moons around Jupiter (1.7–16.7 d) and as Titan's orbital period around Saturn (≈16 d) (NASA/JPL planetary satellite ephemerides)4.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3549631/1

The authors don't list the length of an exomoon's day/month as a factor influencing its habitability, so for the moment we might assume that a habitable exomoon might have a rotational period or day/month of about 1.7 to 16.7 Earth days.

Thus the year of a habitable exomoon, that should be at least 9 times as long as its day/month, might be at least 15.3 to 150.3 Earth days long. But probably shorter than the 224.7 Earth days of Venus or even the 88.0 days of Mercury.

I suggested that each of the eight seasons of the exomoon might last for two to four days of the exomoon, and thus the total year could be about 27.2 to 534.4 Earth days.

Thus the year of the exomoon should be about 27.2 to 150.3 Earth days, and probably in the shorter part of that range.

The natives of the side of the exomoon that faces the planet should have a great view of the planet and any inner moons or rings it may have. Starlight reflected from the planet should illuminate their side very well and might even make it significantly warmer than the other side.

The natives of the far side of the exomoon might not even be aware that the planet exists.

Added 04-06-2017

Iapetus, a much smaller moon of Saturn than the hypothetical exomoon has a large equatorial bulge, with dimensions of 746 by 746 by 712 kilometers, and an equatorial ridge running three quarters around the moon making it look sort of like a walnut. The equatorial ridge is about 20 kilometers (12.42 miles) wide and 13 kilometers (8.07 miles) high.

If the exomoon had such a tall eqatorial ridge winds carrying warm moist air toward it during season A and season C would rain and/or snow on it's slopes. If the ridge was surrounded by tall plateaus like Tibet the precipitation would be snow that might pile up and turn into ice. thus the equatorial regions could be full of glaciers and ice sheets that reflected the light from the star back into space and never warmed up.