What should be characteristics of orbit of planet with sustainable climate if north is covered by ocean and southern by desert?

Question

Planet Artemis depicted at my pictures has totally different characteristics of northern and southern hemisphere. Northern hemisphere is covered mainly by ocean, southern by desert (except two seas, which are fed by rivers flowing from northern regions). Could climate at such planet be sustainable and could exist some circumstances, in which such planet would really exist? Planet Artemis has the same diameter like Earth. Inclination of Artemis axis is little more significant than inclination of Earth and Artemis is orbiting its star similar to Sun.

Here is link of map of planet inspired by Mars: https://www.deviantart.com/giuseppezee/art/Map-of-planet-Artemis-1025507792

I solved issue of climate sustainability in such way, that Artemis has the somewhat elliptical orbit of the planet (one year is orbital period). In perihelion summer is in northern hemisphere, winter in southern. In aphelion summer is in southern hemisphere, winter in northern hemishpere. Atmosphere has characteristics like Earth.

In result - summer in northern hemisphere is intense, hot, with lot of storms, but summers are short. Winters in northern hemisphere are longer, with low temperatures, what is reason for seasonal creation of ice cap in Northern ocean. Thanks all that characteristics I suppose, that ocean in northern hemisphere could be sustainable.

In result - summer in southern hemisphere is long, but due to larger distance from star in aphelion, summer is not very hot. Winters in southern hemisphere are not cold, because star is near in perihelion, but shorter days of winter cause that temperature go not too high despite perihelion. Therefore differences between seasons in Southern hemisphere are not too high like in northern hemisphere. That has impact specifically on region of Southern Sea, which is approximately 2,5-4 km under level of Northern Ocean. Thanks that I suppose, that climate in region of Southern Sea (placed between 30° and 50°) will be warmer as it should be and should be more similar to tropical zone.

So my question is, what should be orbital characteristics of orbit of Artemis (planet size of Earth, with orbital period one year), which would allow, that northern region will be covered partially by ocean and southern by deserts, but difference in temperature in south would be small in seasons - and such system would be sustainable? I am just asking about orbital characteristics, if you would have other remarks, I would also be glad for any comments, but main issue is, whether such system could exist and what would be orbital characteristics. Many thanks in advance for answer, if anybody would have time to check it.

Answer 1

Now, I'm no climatologist or orbital mechanic, but I suspect that you don't actually need to reach as far as carefully planning orbital eccentricities and axials tilts and so on to get the effects you want.

You should have a look at some of the palaeoclimate research on Earth's past supercontinents, like Pangaea. Now, the shape of Earth's supercontinents was driven by plate tectonics and volcanism, whereas Mars doesn't really do that sort of thing, but you haven't specified whether your Mars-with-the-serial-numbers-filed-off shares the same geological (areological?) history as its real world equivalent.

The interior of your southern "continent" could easily be very dry if the right landforms exist to disrupt flow of moist air south, and so would be a desert regardless of its temperature. What you will find though is that seasonal temperature swings are likely to be considerable because oceans do an excellent job of evening these things out and the southern polar cap is a long way from the sea. If you want to keep seasonal fluctuations down, level out that axial tilt and reduce the orbital eccentricity (though unless the latter is very high, it can have less effect than tilt, see Earth's climate for example). On the flip side, seasonal variations generate interesting things like monsoons, so you'll have to compromise somewhere.