WIP (sort of tutorial to be) : Climates, applying Geoff's Cookbook at detail (some)

[Pixie]

So, you went through all the climates and the map looks a mess (or not). Well, climates can be a mess, and the magic wand may not select some pixels, and you may have overlooked some combinations - the remaining is to be done by hand.

And we can start by the following
- there is probably an area very close to the equator that appears to be desert, between areas of savanna or monsoon... Well, it is savanna or monsoon! it's the rainy season in that region that doesn't match january or july (the ITCZ passes through in a different month, in its north-sound annual movement), so it slipped right under out radar.
- in some parts, a transition climate may not be appearing (like tropical monsoon between rainforest and savanna, hot steppe between hot desert and mediterranean, cold steppe between cold desert and continental, etc), add a strip of such climate manually and delete what was there before.

Then, you need to find out bits that aren't colored in any particular color and find the best fit manually (comparing with available information on Koppen classification, like I said before).

Thirdly, time to merge it all together and make it final. But I recommend you duplicate all the layers and simply merge the copies, just to be safe. Once this is done, you can smooth boundaries between regions, make very small micro-climate regions disappear if they are cluttering the map too much, etc.

After some work, including adding a key and a title (work-in-progress, still), this is my end result for the continent of Palamb:

[Naima]

Can u type in also a real wprld sampleof ur climatic zones prototypes? For example cold desert is like Gobi or Atacama?

[Pixie]

Can u type in also a real wprld sampleof ur climatic zones prototypes? For example cold desert is like Gobi or Atacama?

I don't know. Honestly, I think it depends on the location and there was no way it could get that detailed. Read through the wikipedia page on Koppen's Climate Classification, it helps.

[Azélor]

I will comment from the beginning:

I still have no clear idea of your temperature classification but I'm going to take a guess:
extreme is below -38, very cold is below -10, cold is below 0, cool 0-10, mild 10-18, warm 18-22 ?, hot 22-32, very hot is over 32 degree Celsius


BSh and BSk: small detail but it's S and not s, otherwise it mean summer dry
these two climates can have a rainy season, some places could receive up to around 200mm of rain in a month because they are subject to the monsoon (mostly the hot one). Large parts of the steppes in Africa and Eastern Asia are affected. Examples include Niamey and Hohhot.

BSk : is usually found at higher altitude than the hot desert

Dont forget that : (I know it's pretty complicated!)

B. Dry climate: Annual evaporation is greater than precipitation (also called potential evotraspiration). To determine whether a location has an arid climate, the precipitation threshold must first be determined. The threshold value (in millimetres) is determined as:
• If less than 30% of annual precipitation occurs in the summer : Annual precipitation (mm) < 20 × average annual temperature (°C)
• If more than 70 % of annual precipitation occurs in the summer: Annual precipitation (mm) < 20 × average annual temperature + 280
• Else : Annual precipitation (mm) < 20 × average annual temperature + 140

o If annual precipitation is < 50 % of the threshold = BW: desert climate
o If annual precipitation is between 50 and 100 % = BS: steppe climate

So the steppe climates can be more or less rainy if the evaporation is very high too. The same principle stand for colder climates too. They receive much less rain than hot climates but are still considered wet because the evaporation is much lower.

(detail) Also, according to the classification, it's possible to have cold winters in BSh as long as the average yearly temp are high enough. Rare but possible

(detail) BWn: it's an additional class for desert near water that have a small temperature variation like Namibia. I was considering incorporating it


Csb: monthly temperature never go over 22, so it's not hot and not cold either because it never go below 0 (monthly)
I just like to specify that Csc form usually at higher altitudes at it's not very common

Cwb/Cwc: monthly temperature never go over 22, so it's not hot and it's even colder for Cwc, they are located at higher altitudes

Cfb: it pretty sure that the temperature rarely go under 0. And what do you mean by very wet ?

Cfc: : it's hard to say because only a few places are said to have this climate. Like Reykjavik: the temperature difference are small and winters are cool around 0 degree.

D climates: if I have the temperature right for the extreme cold, it should only be applied with : Dfd, Dwd, Dsd and the other colder climates. I tried to find other climates in the D group with winter months under -38 but I could not.

Dfa,Dfb: you inversed the summer and winter precipitations.

[Azélor]

I admit that it's like a puzzle, there is a lot of elements you need to think at the same time. But even so, a puzzle always have pieces that have similarities and that you need to put one next to the other.

I'll try to take a look at the map but do you have a detailed precipitation map ?

[Pixie]

Thanks for your time, Azelor. You've pointed out some important stuff, namely, that I am ignoring the interaction between temperature and "wetness" when considering how dry is a climate. I think the desert/steppe/continental "gradient" will have to be a little reviewed.

The point of this whole system, however, is to skip numbers - this is not because of laziness, but because there are so many "educated guesses" and approximations when it comes to a fictional planet-system that the uncertainty of any number is absurd. I mean, what's the point of saying a given place has a mean temperature of 25 ºC if the margin for such figure is.. say.. 30%. So, that's the rationale behind a fully graphical method, just to explain myself. Of course, you can throw a guess about what exactly "Very Hot", "Hot" or whatever means. I can agree with your guess without second thoughts.
I also want to make this tutorial easy enough for those without a science background - as much as that is possible - and that is why I am trying to define clear and easy to follow rules. Even to the point where some accuracy is lost. I'm not sure how this balance will work out.

Now, as for your valuable comments.

BSh and BSk: small detail but it's S and not s, otherwise it mean summer dry
these two climates can have a rainy season, some places could receive up to around 200mm of rain in a month because they are subject to the monsoon (mostly the hot one). Large parts of the steppes in Africa and Eastern Asia are affected. Examples include Niamey and Hohhot.

So, I will probably have to review some of the combinations. Say, if a region is Very Hot/Hot in a season and Low in wetness, that roughly equates to "Dry" - and it would still be desert. Do you agree with this generalization?

BSk : is usually found at higher altitude than the hot desert

Dont forget that : (I know it's pretty complicated!)

B. Dry climate: Annual evaporation is greater than precipitation (also called potential evotraspiration). To determine whether a location has an arid climate, the precipitation threshold must first be determined. The threshold value (in millimetres) is determined as:
• If less than 30% of annual precipitation occurs in the summer : Annual precipitation (mm) < 20 × average annual temperature (°C)
• If more than 70 % of annual precipitation occurs in the summer: Annual precipitation (mm) < 20 × average annual temperature + 280
• Else : Annual precipitation (mm) < 20 × average annual temperature + 140

o If annual precipitation is < 50 % of the threshold = BW: desert climate
o If annual precipitation is between 50 and 100 % = BS: steppe climate

Altitude is already factored in as one determines wetness maps and temperature maps, so Cold Steppes should appear naturally when a Hot Steppe region is in altitude (and it does in my tests). As for the numbers, I am aware of those, but as I explained I don't think I can bring formulas to this system (Geoff's Cookbook avoided it too).

So the steppe climates can be more or less rainy if the evaporation is very high too. The same principle stand for colder climates too. They receive much less rain than hot climates but are still considered wet because the evaporation is much lower.

As I said, I'll review where some of the combinations fall into, namely between cold steppe and continental (C's and D's) and between hot steppe and mediterranean.

(detail) Also, according to the classification, it's possible to have cold winters in BSh as long as the average yearly temp are high enough. Rare but possible

(detail) BWn: it's an additional class for desert near water that have a small temperature variation like Namibia. I was considering incorporating it

Thanks for these details. I didn't know BWn classification. As for the detail about the BSh, if we don't mention it in "the rules", a piece of hot steppe will be classified as cold steppe, if we mention it, the rule gets more complicated... a choice affecting balance between accuracy and friendliness...

Csb: monthly temperature never go over 22, so it's not hot and not cold either because it never go below 0 (monthly)
I just like to specify that Csc form usually at higher altitudes at it's not very common

This was definitely a choice I made towards friendliness. Merging Csb and Csc allowed for Cold winters. In my tests this covered highlands close to Mediterranean proper (Csa) more than areas immediately poleward of Csa, but it might be a peculiarity of the continent I used. That's why I will have to try this system in different continents.

Cwb/Cwc: monthly temperature never go over 22, so it's not hot and it's even colder for Cwc, they are located at higher altitudes

I get your point but, the thing is, how would you classify a region with Hot summers (over 22) and Cold winters, with sufficient wetness (that's "moderate" or above in the current rules). However, I see Hot+VeryWet Summers with Cold/LowRain Winters falling a bit awkwardly into Cwb - can you find a better fit?

D climates: if I have the temperature right for the extreme cold, it should only be applied with : Dfd, Dwd, Dsd and the other colder climates. I tried to find other climates in the D group with winter months under -38 but I could not.

So, the consequence of this is that all regions with an Extreme Cold temperature should strictly be Taiga or Tundra?

Dfa,Dfb: you inversed the summer and winter precipitations.

Thanks... fixed! (wish all fixes were these simple

As I said, thank you for the help. There's a few questions in the middle of my replies, did you spot them? As for temperature and rain charts, you can see them in a previous post, I have the four side by side when explaining how to "find climate zones".

[Azélor]

You’re probably right, we are just amateur for the most part so using real numbers will only make the process more complicated for a little gain in precision. And most people won’t notice it.
Obviously, if I’m trying to make it simpler, I’m heading in the wrong direction !

So, I will probably have to review some of the combinations. Say, if a region is Very Hot/Hot in a season and Low in wetness, that roughly equates to "Dry" - and it would still be desert. Do you agree with this generalization?

I’m not sure I understand the question. My main point was to say that in Koppen classification ‘’S’’ and ‘’s’’ are two different things.

S: second letter that indicates a steppe and only usable with first letter B
s: also second letter but mean that the summer is dry. Maybe it’s possible to use it with B but for some reasons, it does not apply to deserts BW (because it rarely rain anyway) or steppes BS.

Very hot and dry season = desert or steppe

Since monsoon only occurs in summer the very hot season, it’s impossible to have a monsoonal climate with a hot and dry summer but wet winter. The only that comes to mind is AS but the dry season is only considered dry because the wet season is really rainy. So it’s not that dry.

So it’s either a hot desert or it could also be a hot semi-arid. He does not have to be subject to the monsoon. And if it’s not affected by monsoon, the wet season is also the coldest.
So it means there are two types of hot arid climates, with different precipitation pattern, nice…

So, the consequence of this is that all regions with an Extreme Cold temperature should strictly be Taiga or Tundra?

I guess so. Extreme would not be extreme if it applied to a large part of the world.
This is about the coldest I've found in Dfc, Dwc, Dsc Krasnoyarsk Krai - Wikipedia, the free encyclopedia
Don't forget that the number are based on the monthly average. For example, it's possible to have a temperature of -50 in Manitoba (Dfb) or Mongolia but that's way below their average.

I get your point but, the thing is, how would you classify a region with Hot summers (over 22) and Cold winters, with sufficient wetness (that's "moderate" or above in the current rules). However, I see Hot+VeryWet Summers with Cold/LowRain Winters falling a bit awkwardly into Cwb - can you find a better fit?

Well to start of, there is probably just one place on Earth with a Cwc climate based on the wiki map. Can you find it just by looking at the map ?
It's possible to have it cover a larger area in a fantasy map but it won't be much. But you question is how to classify this climate ? :

Summer: Hot, very wet
Winter : Cold, dry

Dwa maybe ? It's affected by the monsoon but I'm not sure it's wet enough

As for temperature and rain charts, you can see them in a previous post, I have the four side by side when explaining how to "find climate zones".

Really? I mean the 2 central parts are really dry. But I can't say if you did something wrong with the precipitation pattern because that part is really hard for me.

[vorropohaiah]

now this is my kind of thread - just leaving a comment here to make sure im subscribed and to say good work! wish i had the paience to do this with my own world

[Pixie]

Thanks for support, vorropaiah

Now, let's keep the discussion going - the "rules" to identify climate zones are far from finished.

I’m not sure I understand the question. My main point was to say that in Koppen classification ‘’S’’ and ‘’s’’ are two different things.

Very hot and dry season = desert or steppe

I got that, Azelor, my point is about the rule-set I am devising.
In it, a region that gets rain ("Low" level, but still, different than "Dry" level) in any of the seasons doesn't get classified as Desert but as Steppe.
From our discussion, I take it that a region which has a "Low level" of rain but during a "Very Hot" or "Hot" season, should still be qualify as Desert.

Or (a different solution I am also considering).... once the temperature map is finished, use it to reduce the rain level in the Wetness maps in the areas where seasonal mean temperature is "Very Hot". Maybe this would yield the same result and be easier / more graphical.

Since monsoon only occurs in summer the very hot season, it’s impossible to have a monsoonal climate with a hot and dry summer but wet winter. The only that comes to mind is AS but the dry season is only considered dry because the wet season is really rainy. So it’s not that dry.

So it’s either a hot desert or it could also be a hot semi-arid. He does not have to be subject to the monsoon. And if it’s not affected by monsoon, the wet season is also the coldest.
So it means there are two types of hot arid climates, with different precipitation pattern, nice…

I see what you mean. I should split my current rules for Am between proper monsoon and chaparral-style climate (long dry summer plus a really wet but short season).

Well to start of, there is probably just one place on Earth with a Cwc climate based on the wiki map. Can you find it just by looking at the map ?
It's possible to have it cover a larger area in a fantasy map but it won't be much. But you question is how to classify this climate ? :

Summer: Hot, very wet
Winter : Cold, dry

Dwa maybe ? It's affected by the monsoon but I'm not sure it's wet enough

Dwa it is!

Really? I mean the 2 central parts are really dry. But I can't say if you did something wrong with the precipitation pattern because that part is really hard for me.

Yeah, I didn't anticipate it either. But (you can see the detailed, but already slightly outdated heightmap in here), both inland cores (north of the equator and south of the equator) are in the rain shadows of very large mountainranges and fall into desert latitudes. And I had a industrialized nation in it at start.... (they're dead now)

[Corvus Marinus]

I'm really happy to see that you've updated this. I'm moving to the Republic of Georgia in August (for a short-term teaching job), and so am at present very busy getting ready for that, but I look forward to implementing your latest instructions whenever I find time. Keep up the good work!