Plausible climates for this setting map

[lefthandhummingbird]

As a freelance writer for a Swedish RPG, I've often speculated about the plausibility of the climates depicted on our world map, which is a legacy from when the game was made in the nineties. Among the freelance writers, we have often discussed certain things that we consider implausible, so I'm asking for your help in determining what you think would be plausible climates for this world. I'll post my own interpretations, as well as the "canonical" map later. Dark areas represent mountains/highlands.

One thing that might affect interpretation is that the planet is smaller than Earth: 28,858 km around the equator. Gravity is still the same, though, for unclear reasons.

[lefthandhummingbird]

Starting with my approximation of currents. Do they seem reasonable?

[lefthandhummingbird]

Furthermore: pressure systems and winds for January and July.

[Coggleton]

Glad to know I'm not the only one slogging through climatology!

That said, I might be able to give you guys advice from another perspective. I'm GM'ing a post-post-apocalyptic campaign for some of our friends, and part of the setting involves 80m sea level rise (whether or not there's enough water on earth to actually cause that, we haven't thought too much about), which happened due to a macguffin exploding on the moon. If ever you guys run into a problem of your climates making sense, you could always invent some backstory event saying why there's biomes where they shouldn't be. Maybe a desert is where it is because it got glassed from space?

Also, it kinda looks like the Jan/July pressure system maps got fused into one.

[Charerg]

At first impression, this seems like a world very different from Earth: the vast majority of landmass is concentrated in the northern hemisphere in a single monolithic continent, broken up by only fairly small bodies of water. The northern landmass would likely experience extreme seasonality, and ocean-based transport of heat from the equator towards the poles would be severely restricted. A good chunk of the minor seas in the northern hemisphere look to be too closed to play a large role in the global oceanic circulation. Some currents might even be seasonal like the Indian Monsoon Current. The southern hemisphere seems a bit more "standard", and I think you have the oceanic circulation largely correct in that region.

Commentaries aside, nice to see some climate-related threads popping up again. I might even take a stab at drawing my take on the oceanic circulation at some point.

[lefthandhummingbird]

Carrying on, here's my interpretation of seasonal temperatures, or at least roughly what they would be on a normal world (see below):





However, they're probably not correct, given that this is a fantasy setting with certain places that are magically hotter or colder, which should also affect pressure systems. Next, I'll take a stab at making a version which takes these into account.

[lefthandhummingbird]

Glad to know I'm not the only one slogging through climatology!

That said, I might be able to give you guys advice from another perspective. I'm GM'ing a post-post-apocalyptic campaign for some of our friends, and part of the setting involves 80m sea level rise (whether or not there's enough water on earth to actually cause that, we haven't thought too much about), which happened due to a macguffin exploding on the moon. If ever you guys run into a problem of your climates making sense, you could always invent some backstory event saying why there's biomes where they shouldn't be. Maybe a desert is where it is because it got glassed from space?

Also, it kinda looks like the Jan/July pressure system maps got fused into one.

That's what my approach will most likely result in. I'm making maps for how it "should" be so that I can afterwards find explanations for why it isn't like that in the canonical material.

[lefthandhummingbird]

Here's the magically-adjusted temperatures. As you can see, there are a few places that are heated by magic, as well as a spot which is a lot colder than it should be. The placement of these also vaguely indicates which parts of the world have been described in the most detail.

[Charerg]

Here's my take on the oceanic circulation:

Currents.png

The southern hemisphere is largely unchanged. The major difference is the addition of the counter-equatorial currents, which effects the overall circulation. Also, I've treated the circulation in the northern hemisphere differently: I think only one of those bodies of water would be sufficiently large and open that it would have a fully developed circulation. Most of the almost-closed bodies of water would act as a moderating influence, but are too closed to allow for major heat transport via oceanic currents between the equator and the poles (this is just my take on this of course, feel free to disagree ). They would still have local gyres though (which I've neglected to draw here).

I also drew what I think the extent of glaciation would be, though only to a moderate extent (assuming broadly similar avg. temperatures and such as present-day Earth):
Poles.png

Taking a look at your recent temperature maps, that polar lake would likely be subglacial (and certainly fully frozen during winter in the very least), and would not actually moderate the temperatures at all. Climate-related commentary aside, the southern polar continent has a fairly distorted coastline that could use some adjustments (there are methods to reproject polar areas in order to work on them, like GProjector, for instance).

[lefthandhummingbird]

Thanks a bunch! I'll try to adjust stuff accordingly. As for the southern polar coastline, I see what you mean. I highly suspect that the map was made without any concern for that issue, and that GProjector was less available back in the mid-nineties.