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

[Azélor]

@Chareng: The climate transition would vary depending whether it's a large or a small continent.

A... (something), hot steppe, hot desert, possibly some more desert, then steppe (usually the cold one depending on the latitude) , the Csa and so forth.

A clarification on Dsa and Dsb: If you want to make them more common, you would only have to lower the average temperature of the planet by a few degrees. Making so would lower the temperatures of Southern Europe during winter just enough so the average are below zero in winter. The the Csa would become Dsa or Dsb, I suppose unless the change of temperature brings other changes to precipitations.

[Charerg]

@Azelor:
It's intended to be a "mid size" continent, with all those steppes and desert appearing in the interior. Essentially bit of a guideline that will hopefully be useful.


Re: Ds climates

Yeah, if you vary the climate just a little from "present day Earth" the changes in climate types can be pretty massive. Think about the Sahara, for example: the place was largely savannah no more than just 7000 years ago (see Neolithic Subpluvial)! So in that sense it's entirely possible that your world could have a different "climate pattern" than Earth, but keep in mind that those kind of planetwide temperature changes and such have global effects.

For example, a colder planet is also a drier planet, so if you lower the global temperatures, you'd have to take that into account (deserts and steppes would be more extensive).

[acrosome]

I think it would be very interesting to see this method applied to a terraformed Mars. I had always sort of wondered how climate would shake out with one large northern ocean and the immense southern highlands. With, say, a sea level just high enough to flood Marineris. I'm sort of guessing an enormous southern BWk running directly into tundra.

I'm still slowly working on my terraformed Venus, which is a bit more of a challenge in some ways but then again more Earth-like than Mars in others...

[Charerg]

I think it would be very interesting to see this method applied to a terraformed Mars. I had always sort of wondered how climate would shake out with one large northern ocean and the immense southern highlands. With, say, a sea level just high enough to flood Marineris. I'm sort of guessing an enormous southern BWk running directly into tundra.

I'm still slowly working on my terraformed Venus, which is a bit more of a challenge in some ways but then again more Earth-like than Mars in others...

I agree it could be interesting, but I'm not sure if this method can be applied to Mars...because it's a much smaller planet, and I think it would have (has?) a different number of cells in it's atmospheric circulation.

If this site is accurate, Mars would have just one atmospheric cell (transporting air from the equator towards the pole). So, basically the equator and the area between the equator and the ocean would receive rain.

[acrosome]

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?

[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.