WIP Please help me with my climates

[samkatz]

Hi everyone. Last time I posted on here I got a lot of good feedback, so after doing some work on my conworld I am asking here again for all of your critiques. I have it here labeled with Koppen climate zones as best as I could figure them out. The planet is reasonably Earth-like in terms of size, speed, distance from sun, etc. The latitude lines are ten degrees apart from each other. I have a few spaces left white below 60^O, whose climates I'm having particular trouble figuring out. The rest of the zones look a little too even to me across mountain ranges, but I can't figure out what should be different. Can you all please let me know what looks off to you, what should go in the blank spaces in those two regions, what the current setup implies about elevation lower than major mountain ranges, anything else you think I should know?

Map-climate.jpg

[samkatz]

(also, a few tiny white spots are just me painting carelessly - I just got stuck on the two large-ish regions in the western continent)

[Azélor]

I think it looks acceptable but I think the area with BWk in the top centre of the map should be more humid. Cold desert are very rare near the oceans, especially at these latitudes.

[Deadshade]

Like Azelor is saying it is broadly OK.
My comments would be twofold :

- beware of the Köppen classification. It is taylor made for the Earth and there are too many classes. It is "too accurate" to be useful for a fantasy map. Just as an example - a Cwa (or Da) is different from a Cwb (or Db) only by the average yearly temperature. As you won't compute the average yearly temperature (it is possible but one generally doesn't bother), you can't distinguish Cwa from Cwb (or Da from Db) . For precipitation it is even worse - it is generally (almost) impossible to compute it so that you have just a qualitative (e.g here it rains more than there) estimate available. When I use Koppen for my maps, what is rarely, I only use 4 or 5 classes maximum.

- By keeping only the most fundamental climates (Bwh, Af, Cf, Cw), your deserts (Bwh) are too small. For isntance the white spot N on the W continent is a Bwh.
The region on the N continent where you put the lakes (?) is also squarely in the middle of a Bwh climate.
Your Cfa on the E continent will be in reality hot and dry too because it is there where the N and S Hadley cell goes down - e.g very dry, hot high pressure zone in average.
Your Aw's that are equatorwards of the deserts will be in reality B's because the prevailing circulation there is NE to SW (N hemisphere) and SE to NW (S hemisphere). So the winds are hot and dry over continents and hot fast becoming humid over ocans.
Last but not least a D is about 500 - 1000 km away from an ocean, you can't have them on ocean's shores.

[samkatz]

Thanks for the feedback. Deadshade, a few questions.

First, do you mean that those lakes wouldn't be there at all because it's too dry, or just that they would be surrounded by desert?

And are you saying to replace the Aw and Cfa you mentioned with desert?

Lastly, what goes along the shore where I have D's?

[Deadshade]

Thanks for the feedback. Deadshade, a few questions.

First, do you mean that those lakes wouldn't be there at all because it's too dry, or just that they would be surrounded by desert?

And are you saying to replace the Aw and Cfa you mentioned with desert?

Lastly, what goes along the shore where I have D's?

There is definitely a hot, dry desert and no lakes.
No your Aws may be correct . You Cfas are polewards of deserts or at the place of deserts so they would be rather Cs when polewards and Aw when at or near latitude 30°.
The D's depend on scale but a real D could be only on the northern continent where you put it and on the eastern continent where you put it. In both cases they will go over to oceanic when some 500-1000 km from ocean.

You could use Azelor's simplification - only 11 classes some of them obvious.

Personnaly I simplify even farther. I first sketch the general atmospheric circulation and then connect climates directly to biomes. This gives me :
- desert (Sahara like)
- steppe/bushland/savannah (Kazakstan/Kenya like)
- tropical forest
- temperate forest (Europe/US/Japan like)
- tundra
- ice desert

That's 6 and largely sufficient to make a very realistic map with correct colors and textures.
Sometimes when I feel in a perfectionnist mode, I separate the temperate forest in an oceanic humid kind (Ireland like) and continental type (Berlin like). There is not a big difference but it gives a slightly different coloration

[Azélor]

-Af: no dry season à. Just name it ''A wet''

-As/Aw, Am: dry season . As/Aw is the distinction between a dry winter and a dry summer. Dry winters are far more common. Am Use just one of the three. Name this ''A dry''

-BWH vs BWk, both are really dry but one is colder. BWk span at over 30-35 degrees or at higher altitudes. Therefore we can keep only BW for deserts (exepet for the poles) for places with very little precipitation
-BSh vs BSk form FOR SIMILAR REASON. Both generally have a wet seaon and a dry one (usually winter. But again, BSk only span where it's cold enough. BS to use for place that usually have a dry season but the wet season is only moderate.

-Cs for Mediterranean climates, no need to bother here.

-Ds, they are exactly like Cs climates but have temperature below 0 in winter. The impact if usually minimal since it's not too far below 0 for Dsa and Dsb at least. I guess we can put them in Cs or in Df maybe. The other 2 (DSC/DSD) are not common. We can just ignore them.

-Cw, require more knowledge than Cs. I mean, Cs is more consistently found than Cw/Dw. These require a climate with a dry season , often in temperate latitudes. It takes a large continent like Asia to create a high pressure system in winter. It happens only in Asia. If we look at the biomes, the difference between Cw and Cf doesn't seems very large. The dry season is also the coldest, thus the impact is minimized because colder means less evaporation. So we can reasonably put Cw and Cf together. = Cf

-Same thing for Dw and Df, just use Df

As for the temperature letters:

C are usually for oceanic climate, temperate and no cold winters
Ca is for hot climates
Cb/Cc is for temperate climates, Cc is rare so we can just use Cb instead
Da and Db are pretty similar: D continental
Dc and Dd, Dc is usually too cold for agriculture or is very limited compared even to Db. Dd is an extreme climate rare outside Siberia. We can just use


A wet
A dry
Desert (hot/cold)
Steppe (hot/cold)
Cs or Mediterranean climates
Ca for subtropical climates
Cb for oceanic climates
Da for continental climates
Dc for subarctic climates

and lastly

tundra
eternal ice, (ice desert)



How is this simplification ?

[samkatz]

Thanks guys. That's a lot of great stuff both in terms of content and general philosophy of con-climate.

A few things I still have questions about:

What do you think the gulf coast in the southern continent would be like?

When continental transitions to oceanic, does it just get wetter?

[Deadshade]

Thanks guys. That's a lot of great stuff both in terms of content and general philosophy of con-climate.

A few things I still have questions about:

What do you think the gulf coast in the southern continent would be like?

When continental transitions to oceanic, does it just get wetter?

1) The upper gulf part above 30° has prevailing average circulation from SE (trade winds).
That means that the western gulf shore will be very humid especially as there is a mountain which elevates the wet air and generates abundant precipitations. I'd put tropical forest there.
The eastern shore is the contrary. It is in the rain shadow of the mountains so that it is quite dry but warm. Savannah like.

2) The continental climate is characterised by hot/warm summers and cold winters with very variable humidity so that humidity is not a distinguishing parameter.
Because of the necessary large temperature difference continental climate can only be in the interior of large land masses in temperate latitudes (around 50°).
By definition they must be away from oceans which moderate the summer/winter temperature difference. The necessary distance depends from the prevailing atmospheric circulation.
If the prevailing circulation is ocean towards continent, then the continental climate will be far in the interior of the continent.
If the prevailing circulation is continent towards ocean, then the continental climate will be less well defined but could extend nearer to the coast than in the previous case.

In your case assuming the same rotation sense as the Earth, around 50° lat N westerlies prevail. That means that you'lll have oceanic climate on the western side of the continents and continental climate will start far east of the W shore.
Then the continental climate may extend rather near to the eastern shore of the continent. You are Lucky to have very regular continental shapes with no crazy peninsulas and quasi closed seas (Mediterranean, Baltics like) so that it simplifies
What happens at/above 60° is much more complicated so as your planet is not the Earth, it is better to forget it and you won't be much off by just considering that it is a mixture of tundra and temperate forest.

In the S hemisphere around 50° westerlies prevail too. So everything I said above for 50° N applies to 50° S too.

Just for the sake of completeness because I didn't touch this issue yet, I need to add one more thing.
Oceanic currents (like Gulf Stream) and oceanic oscillations (like ENSO - La Nina/El Nino) are defining climates much more than the atmosphere does.
The quasi totality of the energy circulation of the planet happens in the oceans and atmosphere can be neglected for this purpose - atmosphere is a "slave" of oceans.
So if one wanted to be really realistic, one would have to start with oceans first and with atmosphere second. Unfortunately the oceanic side of the problem is not yet well understood even for the Earth so that you could have virtually anything on your fantasy planet.
It is this consideration which lead me to advice you to forget Köppen and restrict yourself to only very few basic biomes (desert, tropical forest etc) .
For that the average atmospheric circulation is a plausible guide.
Any additional detail you might add would be irrelevant and/or wrong because you have no idea what the ocean dynamics on your planet would be.
The only thing that is sure is that it would be very different from the Earth so that what happens on the Earth can't be used as guide.

[Azélor]

Last but not least a D is about 500 - 1000 km away from an ocean, you can't have them on ocean's shores.

Watabout North America? Alaska, Scandinavia, Siberia Tohoku.... It still happen near the coast on west coasts mostly because the land is affected by winds form the interior of the continent.

First, do you mean that those lakes wouldn't be there at all because it's too dry, or just that they would be surrounded by desert?

It would depend on the surrounding hydrography. If there is enough water converging to this area, you could have a lake/sea. The Caspian sea is located in a dry climate but it receive a lot of water form the Volga, located in temperate climate.

When continental transitions to oceanic, does it just get wetter?

The major difference is with the temperature, not the precipitation. Continental climates D have colder winter and summers tend to be slightly hotter too if you compare Cfb and Dfb for example. But then of course, precipitations tend to lower as you move away from the water bodies, slowly.