Ocean currents near the poles

6

I'm trying to create a earth-like world, with different land masses. I want to make a realistic climate scheme and determining ocean currents is a part of this.

I've done some research on ocean currents and know that the gyres turn clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. This I've already tried to draft on my map: enter image description here

My problem: I'm not entirely sure what to do at the poles because, in contrast to earth, I don't want an Antarctica-like current going around the globe. I'm assuming ice caps at the north and south pole blocking this movement. (in the north the ice cap will reach the small continent in the middle of the map 1, in the south the ice cap will cover the most southern island[4] and the southern edge of the continent above that island)

Specific questions:

  1. In the north, the current may pass between the two continents in the middle of the map [1 & 2], however the passage is maybe too small? And even so, the northern hemisphere will still have gyres?

  2. Under the continent in the middle [2], the two gyres left and right of it are flowing in different directions. However I think this is no problem, because this is also happening under Africa.

  3. I am not sure what will happen in the lower left part of the map [3]? Will there be a local gyre?

K VdB

Posted 2019-06-03T13:36:34.517

Reputation: 63

So you mean 2 when referring to the southern cap or 4? Because an ice cap extending north to the landmass labelled 2 would be extremely large if I'm reading the map properly. – Ash – 2019-06-03T13:39:57.353

yes, my mistake, southern ice cap to island [4]. – K VdB – 2019-06-03T14:32:35.070

4(a) A very narrow separation is required to stop currents from forming. Very narrow. (b) The only real way to stop a current from forming is to put land in its way. In your map, you will have polar currents. It's unavoidable because there's no land blocking the flow. (c) I don't believe #4 is big enough to stop a southern polar current from forming without connecting it to #3. IMO. – JBH – 2019-06-03T15:07:03.220

I second JBH. The strait between Number Four Island and the continent will see a roaring current flowing through it, making our Drake Passage look calm. – AlexP – 2019-06-03T15:19:29.463

Thank you for your answers. So what you are saying is that a southern ice cap to the big continent above 4 will not develop because of this current? What if island 4 and the big continent above were connected with each other? – K VdB – 2019-06-03T16:03:55.820

@JBH, why not putting that in an answer? – L.Dutch - Reinstate Monica – 2019-06-03T16:59:08.543

@L.Dutch I might later today. I don't have time to assemble all the ugly details right now. – JBH – 2019-06-03T16:59:56.727

Answers

1

Looking at the map as it stands I would actually expect that the northern and southern oceans would have independent subsurface gyres that would rotate below permanent sea ice. We have similar currents in Earth's southern ocean with the Antarctic Circumpolar Current and on a much smaller scale with the Beaufort Gyre. I would expect the same on this world.

Ash

Posted 2019-06-03T13:36:34.517

Reputation: 36 902