Ocean currents

[Majortopio]

I'm working on a ConWorld for a nationsim game I'm currently programming, that's pretty much based on Earth, and I have a quick question about ocean currents. I generated a world in Fractal Terrains and played around with it a bit, and when I got to a result I as happy with I immediately started adding nations and such. Which turned out to be a bad idea, as I forgot that the area that I want to resemble Europe was placed directly on the world's equator. So I was wondering if playing around with ocean currents could give that particular landmass a Europe-esque climate. (Circled in purple) I've made a map here to check out:

So for one, I was wondering if this is a realistic ocean current situation at all, and then if it would at all help with my climate problem.

[bartmoss]

I don't see any ocean currents on the attached map?

[Majortopio]

I don't see any ocean currents on the attached map?

Oh, sorry, my mistake, I mean ocean temperatures. Slight blending of terms on my part.

Would ocean currents be more helpful?

[cfds]

I would say that the circled area is not very pleasant: Lies (probalby, I can't really tell the scale) on a tropical, the westcoast has a good chance for a cold current (cold water from the north being sucked towards the equator) and there won't come much moisture from east either. I am sure this area is a desert.

[arakish]

Also, which direction does the world rotate? Is it counterclockwise like the Earth (sun rises in the east, sets in the west)? Or is it clockwise? Rotational direction will play a huge part on where the warm and cold currents will be.

rmfr

[Majortopio]

Hmm, I wanted to make it as much like earth as possible, but would it fit more with my needs if it rotates clockwise?

and cfds - well that sucks! Any suggestions on how I could not make the circled area a desert and make it more Europe-esque?

[KeithM]

Also, which direction does the world rotate? Is it counterclockwise like the Earth (sun rises in the east, sets in the west)? Or is it clockwise? Rotational direction will play a huge part on where the warm and cold currents will be.

rmfr

The earth is rotating counterclockwise only if you define North" as being "up". If "south" had traditionally been the "up" direction on maps (and there's no reason why it can't be), then the rotation is clockwise and absolutely nothing changes in the ocean currents or weather patterns. The poles are interchangeable: the real absolute directions on a rotating planet are in the direction of spin (sunrise) and the opposite direction (sunset).

[arakish]

The earth is rotating counterclockwise only if you define North" as being "up". If "south" had traditionally been the "up" direction on maps (and there's no reason why it can't be), then the rotation is clockwise and absolutely nothing changes in the ocean currents or weather patterns. The poles are interchangeable: the real absolute directions on a rotating planet are in the direction of spin (sunrise) and the opposite direction (sunset).

Yep. I was referring to rotational direction as determined by traditional astronomy. North pole is always up, and you are looking down upon the north pole. Of course, there is the magnetic polarity reversal where north becomes down and south up. Then rotational directions will also reverse when referred to from looking down upon the north pole. Thus, it is just a matter of perspective.

Thanks for the change in perspective.

rmfr

[arakish]

Majortopio,

Don't know if this will help any at all. Or it might be too much information.

List of Assumptions
1) The map you created shows only the ocean temperatures, thus black is the land.
2) The map shows the entire world.
3) If the map shows the entire world, then you made the map very close to an Equirectangular Projection, being 4318px × 2130px.

I scarfed your map and loaded it into Bryce and projected it onto a sphere to get some global views. I do this all the time when I create world maps in an Equirectangular Projection. Putting the map on a sphere gives me a better idea on the land mass distortion as one approaches the poles in an Equirectangular Projection. I rendered a global view of Nuelan rotated every 30 degrees. Please note that the 000° is arbitrary in Bryce. I used no control on how Bryce pasted the map onto the sphere (other than telling Bryce to apply it in a spherical projection). I used complete defaults in the program, then rotated the Y axis every 30°. Once I had all the renders, I loaded them into a template I have created in Photoshop that will show me the equator, and 30° and 70° north and south latitudes.

The equators are a darkish green. 30° north and south latitudes are yellow. 70° north and south latitudes are cyan.

The equator, and within 10° latitude, shows where the tropical regions exist. The 30° latitudes, both north and south, show where the subtropical high (STH) regions are most likely to form. The STHs are where deserts are most likely to exist. The 70° latitudes (and on to the poles), both north and south show where the arctic regions are most likely to be. Of course, these are only general guidelines, using Earth as a reference. The orbital obliquity of the world will play a large influence on how large or small the artic regions will be. Land masses and ocean currents can and will change these. However, having these guidelines are helpful. Also included are polar projections showing how the map appears on the north and south pole. The choice of north and south were arbitrarily chosen by me. They may not be the same as you may want.

I had to guess where some of the land was where the violet circle was drawn. All mistakes on these guesses are 100% my error. Sorry if I got them wrong. I also halved the size of the map. Also, it contains not my best drawing...

Using these guidelines, I made two oceanic current maps for Nuelan. One is for the world rotating like the Earth, the other is for rotating opposite Earth. The white arrows show the direction of equatorial rotation. The reddish lines show the warm currents while the cyan lines show cool currents. Some of the cool currents do not change regardless of rotation due to land mass constriction at the poles.

For Reference
nuelanCCW.png - shows ocean currents if Nuelan rotates counterclockwise (sun rises east, sets west)
nuelanCW.png - shows ocean currents if Nuelan rotates clockwise (sun rises west, sets east)
nuelanhurricanes.png - shows a prime breeding area for hurricanes
nuelanpoles.png - shows polar projections of Nuelan
nuelanrotates.png - shows Nuelan rotated in 30° increments

Some more helpful information:
1) Region between 30°N to 30°S, prevaling atmospheric flow will be opposite direction of world's rotation.
2) Regions between 30° and 60°, both north and south, prevaling atmospheric flow will be same direction of world's rotation.
3) In both polar regions, prevaling atmospheric flow will be opposite direction of world's rotation.

If I have made any serious mistakes, then I hope the good folk here will correct me, please.

Hope this helps.

rmfr

[Majortopio]

arakish,

Thanks for all the helpful information and maps! They really help my understanding of how all this works. So basically, no matter what I do, then the circled region in the original map WILL be a tropical/desert-covered area?