Equator Line - Does it have to define my world climate?

[Dalakmar]

Hi All,

I've drawn a map of my game world and chosen an interesting place on that map that I would like to develop further. However, I suddenly realise that this area of interest sits very close to the equator. That would mean Tropical Rains and Drier Climates further out. Unfortunately I want this area to be more Temperate. Other than resorting to 'magic' is there anyway I can accomplish this? Or is it back to the drawing board with my map?

Boy, I wish I'd that about this earlier.

Thanks

Dal

[vorropohaiah]

thats actually a good question that im sure most of us here could benefit from knowing the answer to.

unfortunately i cant help :p hope someone else can though as im intrigued now (and it would also help my world knowing i can explain away such an anomaly without having to resort to the horrid 'magic did it' cliche)

[loogie]

Well, like everything fantasy, no.. you don't... If you're looking for a science behind it, kind of. If you think about it, if your world rotates on an axis, like ours, if that axis is steady, the equator is the line in which the world is always closest to the sun, and therefore the hottest. there are plenty of ways around this simple explanation.. for instance, who says the middle of your map is the equator? the equator is often located on the middle of world maps, but there is nothing saying that's the case. Many maps, especially older maps, would just focus the centre of the map on where they are, or where they see the focus of the world is (for instance, the capital, or region of the ruling faction). if it's geographical, its a bit harder (as in you have decided the north and south are frozen glaciers, meaning they are most likely the far points from the sun... it'd be interesting to play with things like a non-stable axis rotation, meaning the world doesn't spin, it could wobble, or something else, which would modify your climates.

many people don't think about the geography of a world in to much detail, so you could even just leave it unexplained, and let people come to their own conclusions. it's your world afterall, it obeys your laws... it's only magic if you say it's magic.

[Eilathen]

Not necessarily (tropical rainforests on the equator). It depens on how your world-axis is tilted in realtion to the plane it travels around the sun. Unfortunately my geography studies were years and years past...so that is all i got at the moment. But i am sure Hai Etlik or someone who's fit with his/her real world science will soon pop in and tell you in more detail of what i have hinted at.

Or you can go an investigate yourself. I am sure you'll find plenty of stuff if you google for axis-tilt.
As loogie hinted at, the climate depends on how the sun-rays hit the earth (what angle) in the place you want to map out. The wind-cells are also quite important (and directly related to the intensity of the sun-rays in a given area).

[AtmoGuy]

There are a lot more things that you could vary beside axial tilt. You could decrease the amount of solar energy reaching the top of the atmosphere either by increasing the distance to the sun or decreasing the temperature of the sun. That would lead to overall cooler temperatures. You could mess with the composition of the atmosphere, making it more or less transparent to radiation of different wavelengths. For example, invent some otherwise harmless compound that causes the atmosphere to reflect more solar radiation back into space. This would make the average temperature cooler, all else being equal. You could even vary the concentration of this compound latitudinally, so that the mid-latitudes actually absorb more energy at the surface than the tropics.

[loogie]

Oooh. that just made me think of a region with a permanent mist or something, caused by atmospheric compounds.. believe to be magic, but could be explained away at least semi-scientifically.

[Hai-Etlik]

If your planet receives less energy from its star, that would cool everything down, including the tropics. This could result from being further out from the star, or from a dimmer star. The polar regions would also be much colder than ours.

Increasing the axial tilt would reduce the amount the climate varies with latitude, on average, but would increase the variation with season (Hot/Cold or Wet/Dry). So there would be less difference between the tropics and the mid latitudes, but more difference between summer and winter. I think it's also supposed to increase the overall energy of the weather so bigger, nastier, more frequent storms.

I think the equator is stuck being a convergent zone whatever you do, so it's going to be rainy, and the seasonal variation is going to be more a matter of the amount of rain than the temperature: the equinoxes will be the rainy seasons, while the solstices will be dry. At the edges of the tropics, the summer solstice is dry and the winter solstice is rainy. If you go for the overall cooling, I think that would tend to reduce the amount of rain though.

Climatology isn't one of my strong points though so that's a pretty crude model.

[AtmoGuy]

I think it's also supposed to increase the overall energy of the weather so bigger, nastier, more frequent storms.

It definitely would lead to more frequent, more severe storms since storms are largely the consequence of the transfer of energy poleward. The more energy that needs to be transferred, the more storms.

I think the equator is stuck being a convergent zone whatever you do, so it's going to be rainy,

Not necessarily. The equator is a convergence zone because it gets heated more than its surroundings, leading to low surface pressure, which leads to convergence. But, if you could contrive a situation where the equator gets heated less than the surrounding latitudes, then it would be a region of high surface pressure and divergence.

[Midgardsormr]

For a bit of an off-the-wall solution, have you considered sliding your graticule? Just rotate the planet a bit so that what was at the equator is above a tropic. Of course, that will change everything, but I thought I'd throw the idea out there.

[Viking]

If it isn't just easier to move that portion of the map north or south you could consider justifying it by claiming ocean currents may keep things cool. Some ocean currents keep Britain warmer than the latitude would justify and the reverse could be true for your region possibly. As well you could just have the whole planet be cooler than perhaps Earth is meaning you either have larger ice caps or a cooler overall temperature with less variation.