And I thought tectonics were confusing (please critique my currents)

[rvgriffiths]

Hola, peeps. Returning to worlbuilding after a loooong time and I'm running in to all. kinds. of. problems.

I've read and reread the climate cookbook, trawled the posts here and elsewhere, watched the videos, stared at this for waaaaaaaay too long, and I just. don't. get it. Somewhere between "make a water circle. warm goes one way, cold goes the other" and trying to scribble that out on my map, my brain blows a fuse. Are my gyres too squiggly? How far do they go without a continent to smack into? The whorls look so tiny in the live feed and I'm talking myself into decision paralysis.

pls send help.

ONImap currents from hell.png

[Jean-Abdel]

Well... your map is a bit tough for that, it's much easier with big oceans like the ones on Earth, anyway you need arrows to show the direction of movement, and just say that currents going poleward are hot and those going equatorward are cold. Oh, and what is the projection you use for your map? Here it looks like the north pole will have a problem. For the currents, follow the east coast of your big continent from 60°N or S to the equator or another coast, then east until you reach another coast and then north and eventually west until you buckle up. Coasts are coasts of big islands or continents, small islands are easy to get around.

[Jerron]

I would suggest something like this.

Your souther ocean is more or les completely cutt off from any tropical waters, so it should have very cold water.
Your "middle" oceans are somehow surrounded by all those islands and are rather undisturbed by cold waters, while only in the northern oceans cold and warm currents are able to roam free and have a little mix-up. That large north eastern peninsula would make a perfect "Europe" that is being warmed by a "Gulf Stream" while the east coast of the western continent is basically Canada.
currents.jpg

[rvgriffiths]

Thanks Jean and Jerran!

It's just an equirectangular projection (2000x1000) right now. I realize I should have posted the version with the ice caps on it; this one is just the land and water. That makes a difference, right? It seems like it would force cool water southward. I thought they had to be closed loops but not all of the ones on the suggestion seem to be -- maybe I misunderstand currents worse than I thought? The light blue is continental shelf; would the currents go over that? I thought they split at continental shelves.

(Gosh, it must be nice to have a brain that doesn't jump from "Story idea!" to "NOW BUILD A PLAUSIBLE MAP. WITH SCIENCE." At least I've moved on from the days when I angst about just how humans et al evolved on my fantasy worlds... alien space bats. it was alien space bats.)

Map with ice caps -- will throw up a version with another attempt at currents after work.

ONImap currents from hell.png

[Azélor]

The link you provided is a great tool but makes it hard to grasp the actual flow of the oceans, there is too much going on at the same time.
This one might be easier to understand while still very detailed: https://en.wikipedia.org/wiki/File:O...rderless)3.png
Other than that, the wikipedia page has other interesting maps : https://en.wikipedia.org/wiki/Ocean_current
Fluid dynamic is complicated, you don't have to dig too deep to get a plausible world.

ONImap currents from hell.png

Some things to note:

The equatorial currents, it's a mess and actually do not have a big impact on climates since they travel at a constant latitude. The counter current is the weakest and only exist because of the friction from the 2 other parallel currents.
A lot of the current also flow between the islands.
I added polar currents. they flow opposite to the westerlies in the high latitudes. On Earth they only exist in the Beaufort sea and somewhat around Antarctica.
I added some white currents. Some currents aren't really cold or hot nut I haven't spent a lot of thoughts on the temperature of the currents.

Other things:
I think Jean-Abel meant that the north pole is missing a bit of land. You need to have a small strip of land at the edge, or it could be water.
But right now the north pole is made of water and land at the same time. That is not possible.

[Naima]

The link you provided is a great tool but makes it hard to grasp the actual flow of the oceans, there is too much going on at the same time.
This one might be easier to understand while still very detailed: https://en.wikipedia.org/wiki/File:O...rderless)3.png
Other than that, the wikipedia page has other interesting maps : https://en.wikipedia.org/wiki/Ocean_current
Fluid dynamic is complicated, you don't have to dig too deep to get a plausible world.

ONImap currents from hell.png

Some things to note:

The equatorial currents, it's a mess and actually do not have a big impact on climates since they travel at a constant latitude. The counter current is the weakest and only exist because of the friction from the 2 other parallel currents.
A lot of the current also flow between the islands.
I added polar currents. they flow opposite to the westerlies in the high latitudes. On Earth they only exist in the Beaufort sea and somewhat around Antarctica.
I added some white currents. Some currents aren't really cold or hot nut I haven't spent a lot of thoughts on the temperature of the currents.

Other things:
I think Jean-Abel meant that the north pole is missing a bit of land. You need to have a small strip of land at the edge, or it could be water.
But right now the north pole is made of water and land at the same time. That is not possible.

Sorry why is not possible?

[Azélor]

Sorry why is not possible?

Actually, let me explain it better.

First we assume that the planet is a perfect sphere. It's not perfect but the different is very small and it's simpler to work with a perfect sphere.
On a sphere, the pole is simply a dot.
The funny thing is that a dot is a 1 dimension thing, so the area covered by the dot is actually 0.
Therefore to be honest, it's not possible to map the pole.
I guess we have to stop at the latitude 89,99999999...
But this extreme latitude is so close to the pole that it is extremely small. It's size approaching nothing as you move closer to the pole. The infinitely small.
For sanity, we'll assume that it ends when there is only a single atom left. And that is the top and bottom of your map, your poles.
So if the whole latitude is made of only one atom, can it be made of 2 different elements at the same time? Not with current physics, as far as I am aware.
So that's the thing, the pole approaches the infinitely small.

About the current depth:
Most current maps feature only the surface currents, not the thermohaline circulation.
We still don't fully understand the deep water currents and are trying to find how climate changes will have an impact on them and how these current influence the climates.
So I usually avoid including them. That is why the currents are usually hugging the coasts.

The other thing is that it's a simplification. The real current map is the one you linked it the first message. There are many counter-currents, seasonal current, mini gyres, or currents that flow right under the main currents.
All the water in the ocean is constantly moving and it would be very complicated to represent this accurately on a fantasy map. But you are welcome to try as it would probably look awesome.

[Naima]

First we assume that the planet is a perfect sphere. It's not perfect but the different is very small and it's simpler to work with a perfect sphere.
On a sphere, the pole is simply a dot.
The funny thing is that a dot is a 1 dimension thing, so the area covered by the dot is actually 0.
Therefore to be honest, it's not possible to map the pole.
I guess we have to stop at the latitude 89,99999999...
But this extreme latitude is so close to the pole that it is extremely small. It's size approaching nothing as you move closer to the pole. The infinitely small.
For sanity, we'll assume that it ends when there is only a single atom left. And that is the top and bottom of your map, your poles.
So if the whole latitude is made of only one atom, can it be made of 2 different elements at the same time? Not with current physics, as far as I am aware.
So that's the thing, the pole approaches the infinitely small.

Sorry I still do not get it, are you saying that on a planet there is no possibility to have poles without Land?

[Jean-Abdel]

Yes, Azélor is right about the north poles, there's definitely an issue about it. His current map is great too but they tend to follow the coastlines too strictly, I would suggest a mix between his and Jerron's.

[Jerron]

@Azelor: What do the white arrows in your sketch stand for?