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

[Pixie]

I shall be trying this out in a near future (that's when I find the time...), but it looks great and easy to follow.

Just wanted to give my thumbs up for your effort, Azelor!

[Mysterious Mapmaker XXIII]

Hey, Azelor. It's been a while.

So, now that the temperatures are up, what's next? And how soon can we expect it? Thanks.

[ascanius]

Hey Azelor. OK so I got my Temp maps finished. I think they are fairly accurate, I hope. Are you still working on this?

[Azélor]

Hey, Azelor. It's been a while.

So, now that the temperatures are up, what's next? And how soon can we expect it? Thanks.

Precipitations

Hey Azelor. OK so I got my Temp maps finished. I think they are fairly accurate, I hope. Are you still working on this?

Yes, but I got lazy. Can you share the results?

I think most of it is not too complicated but I still got to sort out the effect of altitude on precipitation. It's sounds complicated but it's not, I guess, just a lot of data to check. Problem: air cools off linearly but the rain categories are exponential: the upper limit of the categories are defined by 12,5*2^t where t is the number of the precipitation category starting with 0. (the last category doesn't have an upper limit) So, it means that the orographic lift will be stronger where it's dry at the sea level than where it's already wet. The orographic lift was almost invisible in British Colombia for instance. But then we mix 2 different things. The coast of BC and California is really wet because of : 1- the orographic lift or 2- because the mountains prevent the humidity from crossing over to the other side.

[ascanius]

here are the results.

Jan
Jantemp.png

July
Julytemp.png

I'm still a little uncertain about a few areas, mostly where the islands are, though the western one could almost be it's own continent, It is roughly the size of the eastern US or half of Australia. Thats been my biggest area of trouble is trying to figure out how much of an influence those seas and islands have on everything. For the pressure centers I simply pretended that they were part of overall land mass, which is somewhat seen with the July temps. I also figured that the mountain ranges are going to act as a barrier for the pressure centers and thus temp which is seen with the January temp and how it bends around the area of mountains with the lakes. With the high pressure center in Jan it's actually two, one to the north and one large one to the south of the mountain range. One thing to keep in mind though is that this entire continent is roughly the size of Europe and Asia shifted north.

[Azélor]

I checked it and it's mostly good except some point. Yet, I could be wrong.
ascanius Jantemp copie.png
ascanius Jultemp copie.png

Color code:
Blue is colder
Dark blue is 2 categories colder
Red is hotter, same principle

Summer changes:

• Made the south west coast hotter (like California)
• North West, large landmass can be quite hot, but less so on the coast
• The same is true for the east, where the coast is cooler but interior hotter
• Hotter central sea because semi closed bodies of water accumulate more heat
• Eastern tip, influence of the cold current is more limited

Winter

• Made the south west hotter but the center colder since large landmasses are cooling more than the oceans
• North West is colder
• Interior seas are colder, at this latitude, the water receive less energy and these seas are covered with ice. And most of these seas have little heat exchange with the oceans
• About the pole, the pole is a dot in reality, yet here it is represented as a line. It needs to be of the same color (namely blue). It does look odd considering the area the south of the pole is actually colder but that’s a trick from the projection. Okhotsk sea, even covered with ice the temperature is moderated by the flow of water from the Pacific. About the pole, the pole is a dot in reality, yet here it is represented as a line. It needs to be of the same color (namely blue). It does look odd considering the area the south of the pole is actually colder but that’s a trick from the projection.

---

Other than that, my precipitation model is nearly finished. I just need to sort out 2 or 3 things.

The most problematic is my little understanding behind the Eastern Asia winter monsoon. I know there is a large anticyclone (Siberian High) rotating clockwise, pushing the cold air to southern China and possibly beyond.

So there is a sharp gradient of temperature north /south. I got this but it's not the only place there is one.
There is apparently a semi-stationary front over central china in the winter months. This cold front brings cloudy and rainy conditions. This is caused by the mixing of cold dry air from the north and the hot moist air of the Pacific.
It is close to the tropic, so the westerlies are probably weaker.

That is how I understood it. Am I missing something?
One thing that I'm not sure I understand is how the air from the Pacific is able to travel that far inland.

[ascanius]

Thanks Azelor, So far I'm thinking that this guide is working well. You may want to make the suggestion of going through the guide twice one for practice and one version to keep and use.

[*]About the pole, the pole is a dot in reality, yet here it is represented as a line. It needs to be of the same color (namely blue). It does look odd considering the area the south of the pole is actually colder but that’s a trick from the projection. Okhotsk sea, even covered with ice the temperature is moderated by the flow of water from the Pacific. About the pole, the pole is a dot in reality, yet here it is represented as a line. It needs to be of the same color (namely blue). It does look odd considering the area the south of the pole is actually colder but that’s a trick from the projection.[/LIST]

Doh! Yeah, I feel stupid. I forgot the pole is a single point. The only thing I don't understand is why you made the north west peninsulas warmer in winter? Other than that I understand all the other fixes you did, they make sense once I look at them.

---

Other than that, my precipitation model is nearly finished. I just need to sort out 2 or 3 things.

The most problematic is my little understanding behind the Eastern Asia winter monsoon. I know there is a large anticyclone (Siberian High) rotating clockwise, pushing the cold air to southern China and possibly beyond.

So there is a sharp gradient of temperature north /south. I got this but it's not the only place there is one.
There is apparently a semi-stationary front over central china in the winter months. This cold front brings cloudy and rainy conditions. This is caused by the mixing of cold dry air from the north and the hot moist air of the Pacific.
It is close to the tropic, so the westerlies are probably weaker.

That is how I understood it. Am I missing something?
One thing that I'm not sure I understand is how the air from the Pacific is able to travel that far inland.

I spent about two hours looking at the eastern Asia monsoon. I don't really think the winds have much to do with it. I'm almost willing to bet it is due to the difference in temp and the humidity level and their change throughout the year, It makes more sense in my mind. Sorry I cannot be more help.

[Azélor]

You, I should recommend reading the whole guide before starting?

The north east is warmer... I was going to say that you confused east with west but I did it too in my previous message. The pink means it's 1 category warmer.
I think the blue is too cold to be on the coast, maybe on a closed sea it would be cold enough.

[Deadshade]

The most problematic is my little understanding behind the Eastern Asia winter monsoon. I know there is a large anticyclone (Siberian High) rotating clockwise, pushing the cold air to southern China and possibly beyond.

So there is a sharp gradient of temperature north /south. I got this but it's not the only place there is one.
There is apparently a semi-stationary front over central china in the winter months. This cold front brings cloudy and rainy conditions. This is caused by the mixing of cold dry air from the north and the hot moist air of the Pacific.
It is close to the tropic, so the westerlies are probably weaker.

That is how I understood it. Am I missing something?
One thing that I'm not sure I understand is how the air from the Pacific is able to travel that far inland.

All large scale circulation phenomena are better understood in the vertical plane than in the horizontal plane.
Also temperatures say generally more and are more causal for large scale features than pressures. This has a reason - energy exchages are better described by temperatures than pressures.
I have always seen that people who start modelling climates by trying to locate high and low pressure zones generally struggle to get Something consistent because the causalities are confusing.
The monsoon engine in the vertical plane is quite simple, one needs :
- a large land body (at rather low latitude, say around tropics)
- a large ocean body

As the ocean body is large, it is not far from being isothermal throughout the year.
The land body on the other hand strongly oscillates (the larger the amplitude, the stronger the effect) so that half of the year its temperature is above ocean and half of the year below.
Assuming N hemisphere, in summer the air above land is hot so it rises (corollary is that we have a low pressure but this is irrelevant)
Then in high altitude it must go somewhere. If it goes towards the ocean (here is the difficulty because it is not easy to say where the high altitude air will go) then it will sink above the ocean (corollary is that we have high pressure there).
Then because of mass conservation, the loop must be closed and the wet cold air goes again towards land on ground.
The result is that when this wet air rises again above the heated land, it expands and précipitations occur.

In winter it is opposite. It is the same vertical loop but it rotates in the opposite direction.

All this are necessary conditions but afaik the sufficient conditions for a monsoon regime to occur are not clearly known. Apparently the shape of the land/continent and oceanic currents (or their absence) play a role so that this becomes quite complicated.
For mapping purposes I have always adviced that if you have a large land mass beside an ocean (preferably eastwards) around the tropics and want a monsoon, just put it there.
You will find nobody who would argue that there should be none because nobody knows

[ascanius]

You, I should recommend reading the whole guide before starting?

The north east is warmer... I was going to say that you confused east with west but I did it too in my previous message. The pink means it's 1 category warmer.
I think the blue is too cold to be on the coast, maybe on a closed sea it would be cold enough.

Yeah sorry, I forgot to proofread. Honestly I don't remember what I was trying to say. Anyway keep up the good work.