Mapping an Earthlike planet

[Akubra]

Real life has a way of interfering with my online presence (I'm sure that's the case for everyone). Almost 2 months ago I was planning/hoping to be back online by mid-August. Now the end of September has arrived and I still haven't been able to contribute a post, let alone work on my project. Nothing bad has happened, just different things in real life leaving me very little opportunity to continue my activities here on CG. I have no idea when I will be able to resume where I left off. Next week? Next month? I can't say. But let me assure you, the project isn't dead. It's just forced to take an extended rest. The moment a few things change again, I'll be back working on it, discussing it with you guys, as well as giving my humble input to your own projects. Hope to be back soon!

Cheers - Akubra

[groovey]

I hope you're back soon Akubra, I feel really lonely here with the 3 of you gone. But I'm very glad to hear if you're not around it's not because of bad things.

[Akubra]

Hi folks,

Hope you're all well and thriving!

A month or so ago I woke up from my hibernation to find that the world (this one, that is) was still turning and that the middle of summer had arrived. So, I had a good look at my maps and started working on my own world again. One day it should be turning too.

I took up where I left off all those months ago: rain patterns, temperature and climate. I mainly followed Pixie's tutorial and went through all the steps up to 7. A lot of work, especially step 7.

I'm including the result: 2 rain maps (northern summer/ northern winter), 2 temperature maps (again northern summer/ northern winter), and a climate map.

Rain maps: the colours go from light to dark blue in 6 steps (dry - low - moderate - wet - very wet - extremely wet).
Temperature maps: the colours from low to high temperature are: dark blue (extremely cold) - pale blue (very cold) - green (cold) - yellow (mild) - orange (warm) - red (hot) - dark red (very hot).
Climate map: I used the same colours as in this map (one exception: I used only one colour for Dfc/Dsc/Dwc). White areas mean that no climate has been found for that area.

1. What do you think of the climate map? As said, I haven't yet done step 8, but as it stands now, is it basically realistic?
2. Apart from Dfc/Dsc/Dwc there were no results for climate type D. Is this plausible?
3. I added a few steps for the mountains: starting from 1000m, I made the temperature one level colder for each 750 m higher. Otherwise I would have ended up with a mild temperature at 5000 m and above near the equator. Not very realistic.
4. Other observations?

Rain maps (northern summer/winter):

[PRC]NS-All2000.png [PRC]NW-All2000.png

Temperature maps (northern summer/winter):

[TMP]NS-All2000.png [TMP]NW-All2000.png

Climate map (sorry for the white lines!):

[CLM]All2000.png

Hey, it's nice to have written something here again. Hope I can keep working on this planet for the coming months...

Cheers, Akubra

[groovey]

Long time no see! Glad to hear from you again slacker! And you're back with a bang. I mean I have no idea if there are any mistakes in the maps you posted, because I have no criteria for the climate stuff, though myself will try it soon too.

So I'll be sure to pay attention when the experts do share their input.

[Deadshade]

The precipitation map doesn't seem very realistic.
It is hard to comment on climate when latitudes are not shown. I suppose that you had them but then forgot to show them on your maps. So my comments stay rather general.

What is immediately striking is that your precipitation maps show a circular symetry on continents.
This never happens. On the contrary the atmospheric circulation is always asymmetric and depends on latitude - it is either the westerlies or the easterlies that dominate.
For example if your planet rotates like the Earth then you'll have dominating westerlies in the temperate northern zone. From that follows that the western edges of continents will be much wetter than eastern edges.
This asymmetry is especially important if there are N/S mountain ranges. These will create a very strong rain shadow on the eastern side and very high precipitations on the western side (think Vancouver climate which is defined by that dynamics).

For the temperatures.
T depends on altitude in a pretty linear way - on the Earth it is in average about - 7°C/km . A bit more if air is very dry and a bit less when air is very humid.
That means that a 5 k high mountain in tropics will have 30 °C at foot and - 5°C on the summit. This difference will stay the same in winter and in summer.
Also, on the contrary to precipitations, the temperature distribution is more regular and symmetric. Temperature is basically distributed in latitudinal bands (e.g the average temperature only depends on latitude) with a large discontinuity between oceans and continents.
This is due to the fact that the amplitude of oceanic temperature variations is much smaller than the ampltude of continental variations. It is this difference which creates seasonnal monsoon regimes on approppriate places.

For the details about the atmospheric and oceanic dynamics, you may have a look at the tutorial : http://www.cartographersguild.com/sh...ad.php?t=30482

[Akubra]

Hey groovey, it sure is good to be back! Looking forward to working on these maps again and learning stuff from all you guys.

Thanks Deadshade for your explanation. It does indeed make a lot of sense.

This planet has indeed the same direction of rotation as Earth's and it is comparable in size (slightly larger). I do have a few N/S mountain ranges. There's even one very close to the coast, in the far west of Nohhon, the largest continent. The southern part of it should be under the influence of the Northeast Trade Winds, so I might have a rain shadow on the western side (even if not very pronounced).

I'm tempted to try your approach to the subject and see what climate/biome map it results in. I'll keep you posted.

And next time I'll try not to forget to show latitudes...

Cheers - Akubra

[edit] mixed up east/west. Shame on me!

[Pixie]

My method, as posted, is messed up from step 7 onwards. If you read through my discussions with Azelor, or his discussions with Deadshade in while I was absent, you can pick this up.

I have since improved it and used it personally in Maward (with improvements), but as Azelor is taking the lead on this one, I'm letting him lay down a path we can all try to follow.

As for your maps, I totally agree with Deadshade - the East-West simmetry of each continent, mainly in terms of rain, is definitely an indication that something was miscalculated at some point.

[Akubra]

Hi Pixie, yeah, now it's quite obvious to me too that something went wrong. I'd better read threads till the end in the future.

Anyway, I don't consider the work to be for nothing. I've changed from Inkscape to Gimp, and it gave me the opportunity to learn and gain some experience with Gimp.

Cheers - Akubra

[Deadshade]

. I've changed from Inkscape to Gimp, and it gave me the opportunity to learn and gain some experience with Gimp.

Cheers - Akubra

That's a great victory !
I wish that something would make me go in the reverse direction because I suspect that Inkscape could help me doing some things that are more difficult/cumbersome in Gimp.
But I never had the opportunity for Learning that sofar

[Akubra]

Thanks Deadshade!

I'm certain that for a number of cartography tasks Inkscape would lend itself quite well, and it's not too hard to learn (at least the things I did with it weren't too difficult... ).

When starting to build my planet I chose it because it is a vector graphics editor. I thought that it would allow me to go into as much detail as I wanted, but after some time the program started to get slower because of memory problems―for my planet maps I had thousands and thousands of points defined along Bezier curves―until it finally crashed a few times and became unworkable.

At one point in the future I hope to make some topographic maps with contour lines. They would cover only a small section of my world. Perhaps Inkscape is better suited to those kind of maps. I'll have to look into it when the time comes.

Cheers - Akubra