The Köppen–Geiger climate classification made simpler (I hope so)

[Charerg]

Ah, but here's the really neat thing: no one really knows what determines the number of Hadley cells, so you can make up anything you like. Certainly rotational period matters... and probably size... but also maybe atmospheric density, so once it's terraformed it might have more Earthlike cells. Venus OTOH has a very dense atmosphere but barely rotates at all, so it also only has one Hadley cell per hemisphere.

I'm a bit of a Mars fanboi...

Honestly though, yes, you're probably correct that even a thicker atmosphere wouldn't give tiny Mars more cells. So this might be a nice one-shot project for someone who knows what drives climate and could puzzle it all out. *cough-Azelor* At least figuring out currents in The Ocean wouldn't be comparatively complex.

Hell, maybe someday I'll turn my hand to it. Someone would have to port Azelor's Photoshop script to GIMP first, though. I looked into getting Photoshop but they've gone to a subscription cloud-based model, which I find abhorrent. I mean, $20/month?!? Seriously?

It's also possible to do the final stage (determining climates) manually, though it's very time-consuming. Alternatively you can probably just put your maps in this thread and ask someone with Photoshop to run the script for you (like Azelor did for me, previously).

[Azélor]

I believe that the climate cookbook said that a faster rotation meant more cells while slower rotation is less. While other factors need to be considered I don't know exactly. Mars rotate at the same speed as Earth but Venus is MUCH slower.

A denser atmosphere would make one air cell for each pole, if the pressure is high enough. That is likely what a terraformed Venus would look like. You need a lot a water vapor to do that. The difference between the equator and the Antarctic would be something like 15 degrees Celsius.

If the script doesn't work, you could still do it manually. That's how I recorded the script in the first place.

Here are the instructions if you want to try.

[Charerg]

As a quick side project, I decided to turn one of my hand-drawn world maps into a digital format. Also, for old times sake, I decided to go through Azelor's tutorial to figure out the climate (again), after all, it wouldn't make sense to do it the easy way!

Anyway, this should be somewhat interesting for the climate-enthusiasts around here and help keep the thread alive. This world (called Neuril) won't be super-detailed in terms of topography (nor climate, necessarily) since it's intended as a quick project.

Here's what I have so far:

Elevations:


I forgot to include an elevation key, but it is the same one as in Azelor's Earthly example:

Dark Green: 0 to 250m
Green: 250 to 500m
Light Green: 500 to 1000m
Yellow: 1000 to 2000m
Orange: 2000 to 3000m
Brown: 3000 to 4000m
Dark Brown: 4000 to 5000m
Grey: 5000m or more

Currents:


January Atmospheric Circulation:


I made the July circulation as well, but I later realized that I had screwed up both my circulations by misplacing the oceanic high pressure centers . Fortunately that shouldn't effect the temperatures (much), but I'll probably have to re-do the July circulation before drawing the July precipitation map (I already fixed the January version).

January Temperatures:


July Temperatures:


January Precipitations:


So, basically the July Precipitation is all that is missing before I can move on to the climate definition stage. As usual, if anyone has any suggestions/corrections to offer, those would be welcome. Oh, and btw, any volunteers for running the script for Neuril (I could process the maps manually as well, but it is quite time-consuming)?


Edit:

Actually, there's one place where I could use some opinions, it's this one:



At present, I made the whole area dry (apart from the mountain chain), but I'm a bit uncertain whether this was an accurate solution. Tbh, I'm not sure how this area should turn out. It's in the right place for a desert, but the continent arrangement is a bit unusual compared to Earth. For reference, the 30 S latitude line runs about through the center of the picture.

Also, here are the names of the various areas, for reference:

[Charerg]

Ok, I seem to have outpaced any feedback . I think I'll resort to double-posting considering that my previous post was pretty huge.

Basically I finished the precipitations, although there were several changes to the January version. I realized that in my "dilemma" area there should indeed be a desert which was kind of missing from the previous precipitation map. Also, I had largely forgot to take the "extratropical storm paths" into account, and I added those as well. Anyway, here are the maps:

January:


July:


So yeah, it's on to the climate definition stage, I guess. In case that some generous volunteer wants to run the script for Neuril, I'll throw the Temp maps in the attachments as well. They're basically the same as previously, though I think I fixed one very minor flaw (one mountain range didn't have the 3000m+ elevation taken into account).

[Azélor]

For the temperature it look good. The only improvement I see would be to move the January blue region more to the east of the northern continent. I believe the east would be colder like Siberia mainly due to the direction of the winds and temperature of the western sea being warmer than the north and the eastern one.

About the precipitations.

January, the south eastern part of Urmil could be more rainy as a Mediterranean climate.

I could run the script today unless you have other modifications to do.

[Charerg]

Actually, being my impatient self, I already did most of the work manually . Though I think it wasn't actually a bad idea to sort of "test" the manual instructions. I'm at the stage where all the maps have been combined and all that is left is to pick out the colours corresponding to various climates.

One important tip I did figure out is that in GIMP you need to use the "Addition" layer mode when the (PhotoShop-based) instructions say "Screen" in order to get the exact same colours as in the tutorial (Example: January temperatures layer in "Addition" over July temps in "Normal"). Other than that, I think you should post a larger picture of the "colour blocks", I had to scale them up quite a bit (making the blocks a bit blurry). Otherwise, the "manual tutorial" is pretty good.

Here's how my map looks before the final stage of defining the climates:



I suppose it might be worthwhile to still run the script, just to check if the two methods produce the same result (and to ensure I didn't do any mistakes in my manual implementation).

Edit:

Ok, here is the output:



Not too bad, I have to say. After adding in the steppes, most areas should be ok. Although one area where I was expecting a drier climate was eastern Urmil. I guess I didn't make the summers warm enough so it all turned into Dfc without any deserts appearing. Also, Da climates are basically completely absent. Again, probably because I made the summer temperatures overly mild in mid-latitude areas.

[Charerg]

I went ahead and modified the precipitation and temperature maps (namely temperature). As you (Azelor) suggested, the eastern part of Urmil should indeed be much colder, akin to Siberia. Also, I made the summers warmer. Here are the new temperature maps:

January:


July:


The precipitation maps also received some changes here and there, but as they were pretty minor I think I'll skip posting them this time around. I already processed the new maps manually (it's surprisingly fast once you have some practice doing it), and this is how the climates turned out:



Looking at the polar view of the North Pole, I think it looks ok, although now that I think of it, perhaps the climate is extreme enough that there should even be some Dd climates?



The South Pole looks ok now as well, although the ice cap should probably be a bit more extensive (as in, more circular in shape). Btw, the gradient is in 15 degree intervals in these "polar pictures".



Anyway, at this point I think the temperature maps are (largely) ok, but perhaps the precipitations could do with some extra work.

[Azélor]

Actually, being my impatient self, I already did most of the work manually . Though I think it wasn't actually a bad idea to sort of "test" the manual instructions. I'm at the stage where all the maps have been combined and all that is left is to pick out the colours corresponding to various climates.

It's okay, I understand. When I have a new project, I can't get it out of my head and I can't stop working on it.

Not too bad, I have to say. After adding in the steppes, most areas should be ok. Although one area where I was expecting a drier climate was eastern Urmil. I guess I didn't make the summers warm enough so it all turned into Dfc without any deserts appearing.

Well, as you said, you still need to add the steppes, which can become quite large if the area is flat. (If I remember correctly)

[Charerg]

Yup, I was "on the roll" with the project so decided to go through with it.

Anyway, if you're up for it, I guess a 3rd round of modifications might be worth it. Though I don't think there are any major flaws, maybe you can pick out some areas in the precipitation maps that could be improved?

I ended up changing the peninsula of Orsamarka a little, since it looked too much like a "fat bulb" in the Ortographic projection (see the South Pole map in my prior post). So, this is how the temperatures and precipitations look like now:

Elevations (largely unchanged):


Jan Temp:


July Temp:


Jan Precipitation:


July Precipitation:

[Charerg]

Ok, I've now finished the climates. I can post the relevant temperature and precipitation maps if there's interest, but for now I think I'll just post the results:

Climate map before modifications (should be equivalent to a script-generated map):


And after manual modifications:


Things I did:

- Replaced all Cfc with Cfb and all Csc with Csb (as the Cc climates can't be accurately identified with this model, and they're really marginal in any case).
- Replaced As with Aw (again, really marginal and misidentified because areas close to the equator can get assigned into the wrong category).

Aside from that, I manually added some Dw climates in areas where I felt they were appropriate. And ofc the steppes were added in.