Climate zone map

[davoush]

Hello,

I am trying to make a climate zone map for a map I have been working on for a while. I have tried to keep it mostly realistic, but I think there might be some areas which could be improved.

I have only done the Western continent for now. Some things I have noticed:

The long mountain range on the East coast looks like it would attract precipitation from the north-easterlies, leaving a huge rain-shadow in the interior. This probably means there would be less rivers in the interior, and it would be mostly desert. Does it mean the mountain range on the West would also be unlikely to see much precipitation?

The northern half the content has a large, flat plains-type area around 30-50 latitude. Would this be an arid climate, like those found in Central Asia? I imagine the area near the mountain range would see more precipitation due to the Westerlies.

I wanted the area which is almost an inland sea to have a mediterranean climate, but I'm not sure how likely this is. I think there would be a large desert immediately above it. That Western peninsula around 30-60 latitude is also causing me problems. I think the coast would have a maritime western climate, but I don't know if that would extend across the whole peninsula.

Any comments or suggestions would be great. Thanks!

Key:
Green - Rainforest and Savannah
Yellow - Desert
Orange - Mediterranean
Light blue - Maritime West Coast
Pink - Temperate continental
Brown - Plains/Steppe/Cold desert (?)
Purple - Cool Temperate East

[kacey]

Hi Davoush, I'm no climate expert, but I'm currently working out a world climate of my own right now so I'll be interested in seeing what other people have to say, hopefully someone else chimes in on this because it would probably help me out as well.

I think you're probably right about the mountain range on the east coast, but I think the area right above that where the two land forms connect would be wet as well because of warm moist air coming up that coast from the equator. I'm not sure, like I said I'm no climate expert so take what I say with a grain of salt...

I like the way you've set up you're land masses I'll be watching to see how this progresses.

[Eilathen]

I do think it looks pretty reasonable just from the picture and how the continent is situated on the different latitudes.

BUT ... this is all without data on how the wind-systems and the ocean-currents etc etc look like. Because those are big big climate factors. Also, mountain-ranges are climate indicators/influencer as well.

So, in short, if you are not too hung up on absolute precision (aka a very much realistic background with all variables) i think you are good. If you want this to be really REALLY realistic, you have got a lot of work to do before you can even think about climate-zones. Axis tilt of the planet, rotation of the planet and therefore wind-systems and ocean-currents etc etc. .

[davoush]

Thanks Kacey, hopefully people's comments will also be useful/applicable to your map. Regarding the 'bottleneck' area in the North - I think the latitude this is at would make it quite arid, especially if above and below is also desert. It might be tempered somewhat by the surrounding water.

@Eilathen, I'm not too concerned about 100% precision, but I would like it to be semi-realistic at least. I did try to work out the basic wind directions, etc. which is how I arrived at some parts, but I suppose this needs more thought. The planet itself is basically an alternate earth with different landmasses (partly just to make it easier to work things out).

[Charerg]

Like Eilathen mentioned, if you really want this to be accurate, you need to at least consider the oceanic circulation and how it would affect the atmospheric circulation (having an idea about those two will allow you to locate the deserts more accurately than just based on latitude). Concerning desert formation, it's worth noting that they tend to form at the western sides of continents (this ties into the oceanic/atmospheric circulation, oceanic high pressure centers like the Azores High form at the eastern margins of oceans in subtropical latitudes). Only in very rare cases will you find a desert on the eastern coast of a continent, even in "desert latitudes".

With that in mind, I agree with Kacey that the bottleneck area would probably not develop a real desert. It looks like something very similar to Meso-America, and might even be rainier because it has a "Gulf of Mexico" both east and west of it, creating traps of warm water. I'd say that most likely only the northern side of the "western Gulf" would develop a desert.

[davoush]

Like Eilathen mentioned, if you really want this to be accurate, you need to at least consider the oceanic circulation and how it would affect the atmospheric circulation (having an idea about those two will allow you to locate the deserts more accurately than just based on latitude). Concerning desert formation, it's worth noting that they tend to form at the western sides of continents (this ties into the oceanic/atmospheric circulation, oceanic high pressure centers like the Azores High form at the eastern margins of oceans in subtropical latitudes). Only in very rare cases will you find a desert on the eastern coast of a continent, even in "desert latitudes".

With that in mind, I agree with Kacey that the bottleneck area would probably not develop a real desert. It looks like something very similar to Meso-America, and might even be rainier because it has a "Gulf of Mexico" both east and west of it, creating traps of warm water. I'd say that most likely only the northern side of the "western Gulf" would develop a desert.

Thanks for the response. I have begun working out currents. I'm not sure how accurate this is, but hopefully it gives a generally realistic impression of currents. It seems like you are right - The Eastern side of the bottleneck is surrounded by warm currents. I'm quite unsure with how to deal with all the bays and peninsula areas. Also, would the chain of islands affect the current?

[kacey]

I'm glad some more people chimed in, this thread is definitely helpful to me because the land masses, and general layout for the map I'm working on aren't dissimilar to yours, probably because I'm also trying to do something earth like. I've never really tried working out the climates for an entire world so I was also thinking that doing an alternate earth style map might make things easier as well. My map also has a bottleneck at a similar spot only south of the equator, I was thinking it would be similar to the gulf of Mexico which is why I put it in, but I was thinking I was wrong for a minute, and was about to change it until I checked this thread again the morning so thanks for posting it, I'm sure others will find it helpful as well.

[davoush]

I have made a preliminary map showing possible wet areas in the Northern Hemisphere in winter. The landmass on the East of the Eastern continent will most likely have very wet summers, and dry winters, similar to parts of China. It could even be monsoon. The Yellow areas mark rain shadows. I am unsure whether the islands would get a lot of rain as the large mountains on the Eastern continent might get most of it. Maybe the islands closer to the Western continent would get more. I have ignored the ITCZ for now, assuming that rainfall will be plenty in this region (although, the ITCZ runs right through the Arabian peninsula which is extremely arid - anybody know why?).

I am also unsure how far inland I should extend some wet areas, for example the West coast of the Eastern continent. Would it rain quite a lot up until the mountains, or would most just fall on the West coast?

Attachment 94018

Thanks.

[Charerg]

Your currents are pretty good, generally speaking (they flow in the right direction and so forth). However, currents have a tendency to form loops, they don't normally have sharp turns. Also, those loops match the atmospheric cells. You're going to have a loop that matches the Hadley Cell, another for the Ferrel Cell, and a third for the Polar Cell. Here's my suggestion for the currents to demonstrate the point:



Here, I've omitted the polar high pressure centers, but otherwise this should demonstrate the concept. Generally, it's fairly similar to your version. The main difference is probably the "west Gulf", where I believe the cold current would not reach into the Gulf, because this would require a U-turn around that narrow peninsula that separates the Gulf from the Ocean (which is unlikely, imo).

Also, I believe the shape of the landmasses would cause the Equatorial Countercurrent to have a slight northward bias. In general, I think you made the Eq. Countercurrent hug the equator a bit too tightly. Take a look at this map of Earth's oceanic circulation: from wikipedia. If the circumstance are right (the Indian Ocean), the Eq. Countercurrent can cover a fairly large area.

Other than those differences, it's very similar to your version. This is just my (hopefully somewhat helpful!) suggestion ofc, so feel free to use, modify, or ignore it.

Edit:
I realized that I wrote that the loops match the atmospheric cells. That is actually not quite accurate. While for the polar cell, it may be said that easterly flowing currents surrounding the pole(s) match the polar cell, this isn't quite accurate for the other loops. Well, it's true in the sense that the oceanic circulation should likewise have 3 major loops per hemisphere. However, they don't really match the atmospheric cells in terms of shape. For example, the Gulf Current in the southern Atlantic is driven by the Trade Winds (that are part of the Hadley Cell), but the westerly flowing Gulf Current in the northern Atlantic is driven by the westerlies (which are part of the Ferrel Cell). Hopefully this disclaimer clarifies my earlier statement (though I have a feeling I may have just made things more confusing, rather than explaining them).

Edit2:
I also realized that I wrote that the Eq. Contercurrent can reach as high as 15 latitudes (I seem to be having a bad day when it comes to making factual statements). It doesn't, of course. What I meant to say was that the actual (easterly flowing) Equatorial Currents can be pushed as high as 15 (rather than being located exactly at the equator)!


Aaand.....yet another edit!

You asked why the Arabian peninsula is arid, despite the ITCZ being situated over it in July. I'm not an expert as such, but I believe it's because of wind directions. As you probably know, the trade winds are easterly flowing (that is, from east to west). However, as usual, there's a little exception to this rule: if the trades cross the equator, the Coriolis force turns them into westerly flowing instead! Here's a quick map to demonstrate the concept:



As you can see, the winds that reach the Arabian peninsula tend to come from the interior of Africa (not from the Indian Ocean), and are probably already largely drained of water by the point they reach Arabia. I think this is the main reason why the area is so arid, but again, I stress that I am just a hobbyist, not an expert, so there may be other reasons as well.

[davoush]

Wow, thanks Charerg! That is all very helpful! I will certainly be updating my map based on your suggestions.