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Majortopio
09-16-2010, 12:08 PM
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
09-16-2010, 01:14 PM
I don't see any ocean currents on the attached map?

Majortopio
09-16-2010, 01:39 PM
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
09-18-2010, 08:20 AM
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
09-19-2010, 05:19 AM
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
09-19-2010, 06:22 AM
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?

arakish
09-19-2010, 12:59 PM
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 30N to 30S, 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
09-20-2010, 02:27 AM
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?

jbgibson
09-20-2010, 10:19 AM
How much does the rest of the world's climate matter? Given a generally earth-like situation, arakish's (amazing!) work could be a fair representation of 'plausible fiction'. But if you dial the axial tilt, distance from sun, cloud cover, amount of icecaps & continental glaciation up and down, you could probably get any small area *exactly* how you like. The rest of the planet might shift uncomfortably toward frozen, or desert, or what-have-you.

Arakish, the way those currents swirl seems reasonable. Especially since the continent blocks global flow, those three small seas to the east of the desired Europe-like area probably are very warm, self-circulating hot-tubs. Overall though, there could be some circulation that gets the Europe Analogue Isthmus some cooling, some rain without being a jungle, etc. Prevailing surface winds drive a lot of the surface currents, along with coriolis forces and the fact that these inconvenient continents generally get in the way :-). Maybe a judicious application of the pseudoscience of the wind tutorial (http://www.cartographersguild.com/showthread.php?11964-Where-does-the-wind-blow) I've started could "justify" appropriate climate.

Another consideration is just how stable do you want Nuelan's climate to be, over time? If it wobbles a bit on its axis, or if its sun is a little variable, you could pick your desired point on a cycle of cooling... glaciation... warming... desertification... repeat.

Majortopio
09-20-2010, 03:58 PM
The rest of Neulan is allowed to be almost desert/desert areas, that would actually fit quite well with the storyline that I have in mind. And in regards to climate stability.. I suppose I could, how long would those cycles last though? The game I'm building is set in a slighty futuristic timeline, in a world thats economically and culturally collapsing, and that has been ravaged by the careless human race, so maybe an added aspect of sudden desertification or whatnot could add an interesting spin.

But I'll take a look at that wind tutorial then, I'm willing to do anything to get this to work.

arakish
09-20-2010, 05:14 PM
Please note that all of the attached images are "general idealized" maps since I have no idea of the landforms of Nuelan. To be more specific with these maps, I would need to know where the mountain ranges are, and their topographic and geopspatial ranges. For good examples of how mountain ranges can affect these "general idealized" maps, look to the Himalayan and Andean ranges here on Earth.

Also, the world's axial tilt will play a large role on how the climate and atmospheric flow zones will shift north and south as the world revolves around the primary (sun) and the seasons change. The maps I created below are based on an axial tilt like Earth (23 26' 16" or 23.438) and a revolution period like Earth.

I also added 60 latitude lines (red) on all the maps (explained below).

As before, the white arrows show the direction of rotation.

General Idealized Atmospheric Flow

Attached Files
nuelanAtmFlowCCW.png
nuelanAtmFlowCW.png

These images have the red lines showing the 60 latitudes. I added these because the "general idealized" atmospheric flow will be in regions 0 to 30, 30 to 60, and 60 to 90 (the poles) in both north and south latitudinal regions. As mentioned before, I had the 70 latitudes to show where the primary polar climates will be.

This is a nice tutorial (http://www.cartographersguild.com/showthread.php?11964-Where-does-the-wind-blow) made by jbgibson of how the General Atmospheric Flow can develop on a world.

General Idealized Climate Zones

Attached File
nuelanClimZone.png

Again, remember that this is a "general idealized" map. It should give you a good idea on how the climates will be around Nuelan. If not, then ask and I or others here will be glad to answer.

Region of Interest

And to answer your question. The region of interest (ROI) in question will actually have varied biomes. Along the equator, the equatorial region of the ROI will be tropical rainforest/tropical deciduous forest. As you go northward and southward towards the subtropical highs, the biomes will phase through tropical deciduous forest to troical scrub to tropical savannah to semi-arid and arid desert.

Attached File
nuelonROIClimZone.png

This map shows the general idealized climate zones and the ROI. Hope this is the ultimate helper.

And as always, if I made any serious errors, the kind folk here will correct me, please.

rmfr

P.S. - just saw your post post jb... now there are two links to your tut ;-)

arakish
09-20-2010, 05:30 PM
And in regards to climate stability.. I suppose I could, how long would those cycles last though?

That is dependent upon a lot of factors. The Earth's axial tilt wobbles between 21 and 25 (approximation) degrees. Many scientists believe these wobbles (Milankovitch Cycles) are what help to create the Earth's periods of glaciation and warming. Basically, these wobbles are caused by the system's primary and all other planet's in the stellar system playing constant tug-of-wars on the Earth.

Of course, if you believe in the Nemesis Hypothesis (a coalstar with tremendous gravity well is in an elliptical orbit around our sun that cycles every 65,000,000 years (or so)), then Nuelan's Nemesis could be passing close and thus throws Nuelan's axis off. Of course, there is the perterbations of any comet and asteroid orbits that can cause a shooting gallery...


...so maybe an added aspect of sudden desertification or whatnot could add an interesting spin.

Also, there is the magnetic field polarity reversal that can cause all kinds of havoc. It has even been proven here on Earth. In the studies done on the mid-oceanic ridge in the Atlantic, they have found that as the ridge feeds new ocean floor, that it has created stripes of magnetic reversal. I'll look for some links about this and post them.

rmfr

arakish
09-20-2010, 05:52 PM
Didn't take me as long as I thought. Unless you want more reputable links...

Milankovitch Cycles
http://en.wikipedia.org/wiki/Milankovitch_cycles

Magnetic Polarity Reversal
http://en.wikipedia.org/wiki/Magnetic_polarity_reversal

Plate Tectonics
http://en.wikipedia.org/wiki/Plate_tectonics

Mid-Oceanic Ridges
http://en.wikipedia.org/wiki/Midocean_ridge
This one has an animation of magnetic striping towards the bottom of the page.

Gads, ya gotta love wikipedia. However, also note that you have to judge the validity and accuracy of the information for yourself.

Hope these can be of some help. I have textbooks from my geography courses, but refuse to scan them due to copyright issues.

General Question: If I cut/paste a URL in a reply, do these forums automatically convert them into a link? Other forum boards I visit do this. Just don't know about these.

rmfr

Majortopio
09-22-2010, 12:47 PM
Wow! Thanks for the more the in-depth help and images, I will use these to their fullest!

KeithM
09-28-2010, 06:29 PM
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
09-28-2010, 07:53 PM
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