Ocean Current Map: enter image description here The straight red lines are 60* North and South, and the straight blue lines are 30* North and South. The curved blue lines with an arrow represent cold currents, while the curved red lines are hot currents. Black curves are neutral, with no sigificant heat exchange.

To keep the question simple, assume that the ocean depths are about 1,200 meters around the continents, and on average 4000 meters worldwide. The planet in question is about 100 million miles away from the Sun, just slightly cooler than the Earth. It also rotates prograde 16 times slower, so it only has one cell per hemisphere. For anything else, assume the planet in question is identical to Earth.

Using the wind map below, and the planetary characteristics, are these ocean currents realistic?

Wind Map: enter image description here

Bonus question, but not really critical:

  • Does there need to be more or less ocean gyres/ocean currents?


  • Other questions have asked about ocean currents on a planet with a rotation period different than this question, so I do not think this counts as a duplicate. Feel free to correct me though!

Scale Map: enter image description here

  • 2
    $\begingroup$ I am confused. The map looks like the continents are clustered really close how much ocean is between them? $\endgroup$
    – 11Bravo
    Jan 8, 2021 at 18:47
  • $\begingroup$ @11Bravo I just added a third map with scale, sorry about that. Do the various measurements clarify the map better? $\endgroup$
    – Mandelbrot
    Jan 8, 2021 at 19:22
  • 4
    $\begingroup$ Does this answer your question? Can someone help me with ocean currents? I'm really confused $\endgroup$ Jan 9, 2021 at 1:17
  • $\begingroup$ @DarthBiomech Yes that helps a little bit, the only issue is my planet rotates slower and therefore has only one cell per hemisphere. Do you have any other resources that involve longer rotations? $\endgroup$
    – Mandelbrot
    Jan 9, 2021 at 5:34
  • 2
    $\begingroup$ Why is there hot water near the poles and cold water closer to the equator? What heats it up? $\endgroup$
    – Peter Shor
    Jan 10, 2021 at 19:42

1 Answer 1


There's something screwy going on down south:

I haven't built a model of the fluid dynamics, but my eye is drawn to a region of water deficit and surplus, that's also asymmetrical.

enter image description here

What is going on with the current annotated A->C?

  • The prevailing wind is going in the north.
  • The prevailing current from planetary rotation is eastward and equator-ward - roughly symmetrical with the northern hemisphere.
  • Is water is just magically appearing at A?
    • Flow from gyre to A is going to be negligible - if it's substantial enough to explain the water deficit then the flow is enough to swamp the gyre.

Same with C->B:

  • Is water just being magicked away at B?
  • Full flow is not going B->gyre (due to I'm assuming the island almost blocking the channel), otherwise there'd be notable flow B->A at 30 degrees S enough to destroy the gyre.

I reckon this'd look like this:

enter image description here

I guess as a fundamental rule there's the conservation of water: Water flowing into a region needs to flow out of it - water flowing out of a region needs to get to it.


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