Rheia: one final try at ground-up worldbuilding

[MrBragg]

Nice then could be an alteration of those parameters that gives abnormal temperatures on continents like I read before?

When I ran the simulation for Rheia I kept all of the parameters identical to Earth's except for the heightmap. ExoPlaSim consistently seems to overestimate temperatures--it does so by several degrees for Nikolai's baseline earth model--and I had to drop the CO2 levels by >50% to get more reasonable temperatures for my simulations. I could do that here, too, though Tiluchi seems to have already done a really nice job of hybridizing the ExoPlaSim results with their intuition.

[worldbuilding pasta]

Some useful notes regarding the exoplasim comparison:

Air Pressure:

2: Probably a resolution issue. Generally expect exoplasim outputs to be not totally reliable for mountains

3: See later notes on temperature

4: For somewhat thin continents this is not necessarily unrealistic, compare to Earth's southern hemisphere. Also bear in mind that panoply is sort of auto-fitting the color range to the range of pressures in the output; when comparing the color maps between the model output and Earth or your own drawings, make sure they're on roughly the same scale before reading too deep into them.

Winds:

MrBragg is right, you're seeing top-of-atmosphere winds there. I would suggest going to the highest-level winds of the output, closest to the surface; For an Earth-like pressure profile with 10 layers I think even 1 layer up is something like 1-2 km above the surface.

Temperature:

1: That sort of temperature range isn't necessarily out of the question for a hotter climate, that may have existed in some areas in the Cretaceous. Did you change any parameters of the model other than topography?

2: It seems like your overall average temperature is a bit higher than you were aiming for, you might want to adjust down CO2. Even aside from that, exoplasim tends to output somewhat too warm poles because it underestimates glacial cover; I mentioned to Mrbragg in their thread that starting the model with 1 meter of global glacial cover seems to get a more realistic distribution, though it does also make the model take longer to balance out.

4: Resolution issue again.

Precipitation: When looking at precipitation outputs directly I'd recommend putting them on a logarithmic scale, because rains in the tropics are just so much higher than everywhere else that they drown stuff out. Again, beware of reading too much into the map colors when panoply is just auto-fitting these to the data range without using any sort of objective scaling. Also be aware that the "precipitation" zones used for hand-drawn climate processes are not really meant as direct proxies for precipitation, but moreso the precipitation/evapotranspiration ratio. A hotter region will require more precipitation to remain wet compared to a colder area. This is part of the utility of koppen zones, this complexity is accounted for in how wet and arid zones are defined.

1: Probably a resolution issue again, it's something I have to investigate further, but in this case it may also be related to the over-warm poles.

4: This may also be partially a resolution issue, the model may not be able to capture the full profile of coastal lowlands between a mountain range and the sea. I think this is also why it tends to mark tropical islands a bit too dry, if an island only occupies a single cell it may not capture the orographic effects that encourage rain there.

[Tiluchi]

Some useful notes regarding the exoplasim comparison:

Air Pressure:

2: Probably a resolution issue. Generally expect exoplasim outputs to be not totally reliable for mountains

3: See later notes on temperature

4: For somewhat thin continents this is not necessarily unrealistic, compare to Earth's southern hemisphere. Also bear in mind that panoply is sort of auto-fitting the color range to the range of pressures in the output; when comparing the color maps between the model output and Earth or your own drawings, make sure they're on roughly the same scale before reading too deep into them.

Winds:

MrBragg is right, you're seeing top-of-atmosphere winds there. I would suggest going to the highest-level winds of the output, closest to the surface; For an Earth-like pressure profile with 10 layers I think even 1 layer up is something like 1-2 km above the surface.

Temperature:

1: That sort of temperature range isn't necessarily out of the question for a hotter climate, that may have existed in some areas in the Cretaceous. Did you change any parameters of the model other than topography?

2: It seems like your overall average temperature is a bit higher than you were aiming for, you might want to adjust down CO2. Even aside from that, exoplasim tends to output somewhat too warm poles because it underestimates glacial cover; I mentioned to Mrbragg in their thread that starting the model with 1 meter of global glacial cover seems to get a more realistic distribution, though it does also make the model take longer to balance out.

4: Resolution issue again.

Precipitation: When looking at precipitation outputs directly I'd recommend putting them on a logarithmic scale, because rains in the tropics are just so much higher than everywhere else that they drown stuff out. Again, beware of reading too much into the map colors when panoply is just auto-fitting these to the data range without using any sort of objective scaling. Also be aware that the "precipitation" zones used for hand-drawn climate processes are not really meant as direct proxies for precipitation, but moreso the precipitation/evapotranspiration ratio. A hotter region will require more precipitation to remain wet compared to a colder area. This is part of the utility of koppen zones, this complexity is accounted for in how wet and arid zones are defined.

1: Probably a resolution issue again, it's something I have to investigate further, but in this case it may also be related to the over-warm poles.

4: This may also be partially a resolution issue, the model may not be able to capture the full profile of coastal lowlands between a mountain range and the sea. I think this is also why it tends to mark tropical islands a bit too dry, if an island only occupies a single cell it may not capture the orographic effects that encourage rain there.

Thanks! This is indeed all super useful, much appreciated. No parameters were changed with the model- unfortunately I don't have the processing power or programming knowledge to run ExoPlaSim on my computer, but MrBragg was kind enough to run the basic model for me. You're right that a lot of this is a mix of resolution issues and the fact that ExoPlaSim tends to model things quite a bit hotter than we expect. I've been adjusting my climate map based on the ExoPlaSim output and the output I got from doing things manually- ultimately the results aren't particularly far apart with a couple notable exceptions. Will probably stick to this approach since I can't really run the model on my own, but having ExoPlaSim output is definitely useful for checking if my intuition on some complicated things like precipitation is correct.

[Naima]

Do you have a blank map ? If you agree I would like to test the climate for your map with my thumbs rules I am working on for cimate tutorial , so I do not want in anticipation to check the maps you or exoplasim did to not get influenced.
In case I need coastlines, sea and elevation together to know how high is a zone.

[Griff Gruver]

This map was coming along beautifully. I'm currently just starting the process of following Worldbuilding Pasta's tutorial on using GPlates to create a tectonic history.

Just wondering if you have made any additional progress since your last update earlier this year?

[WoodytheClimateGuy]

I just wanted to say that the progress made was wonderful! I kind of wanted to give a draw at selecting the climates based on the maps you showed, although this is the raw results based on the slectiont tool. So, I made an unofficial Koppen climate map of Rheia. I just did this for fun and feedback though. So, what are your thoughts?

Rheia - Koppen Climates.png

And here's the key I used. (I made a new color of Csc)
Koppen Climates.png

Hope this is good!

[Tiluchi]

Wow, I really dropped off the map (no pun intended) here didn't I? Not because I stopped working on the map, although I've been traveling for work most of the year so I haven't had nearly as much time as I'd like to work on it. I've gotten to a point where I'm fairly happy with the climates and am find mostly moving on to other things before I get caught in an endless loop of second-guessing myself about complex natural processes. Currently working on putting together a decent shaded relief map of the world, as well as more general worldbuilding things like flora and fauna.

Anyway, Woody the map looks great! And broadly similar to the final-ish climate map I put together for my world, which I guess it reassuring that I'm not just totally off base with that. It does seem that you limited the extent of hot deserts even more than I did compared to what ExoPlaSim spit out, which of course I prefer since hot deserts are sort of a drag worldbuilding-wise. Was your work done based on the Azelor/Charerg/AzureWings tutorial here on CG or did you make some modifications?

Naima, it's a bit late now but I'd be happy for you to take a stab using your own methods! I think all the "raw" maps (elevation, etc.) should be on this thread, unless there's something else you'd need?

Posting here my final-ish climate map; will post my attempt at shaded relief whenever I've had a chance to progress further on it.

Rheia_climates.png

[WoodytheClimateGuy]

Nice that you're back in the game! Anyways, I really like the Koppen climate map, and you did way better than me, which makes sense.

I mostly just used Photoshop to do a raw selection of the climates. First, I did the aridity index for both seasons, then I did the climates. Could you also show the aridity index for both seasons? Because I was unsure in some bits because the tutorials used a different temperature scale than yours, but yours allowed for more accuracy. I had trouble with the hot deserts since some deserts had a semi-arid season according to the aridity maps, I had, so I think I missed up on that front.

So, great job on your maps!

[meatulpa]

This is all super educational and inspirational to read while I struggle with my own process. This thread caught my eye, as it shares a name with my daughter, Rhea! Super interested in seeing what else is to come.

As a side note, I've been struggling to get exoplasim running without errors and will try my hand at working up the climate by hand. Was this a time intensive process for you in relation to, let's say, the tectonics?

[Tiluchi]

Posting another semi-yearly update on this, now that I've finally made some progress on doing a shaded relief map. Still pretty much a novice at Photoshop so this is the result of a great deal of trial and error with lighting effects and various filters. Still need to go through and work on some of the climate boundaries to make the map look a little more "natural" but I'm starting to be happy with the general style. I'm not going to be able to make the detail necessary for a proper realistic-looking DEM so instead I tried to make the shaded relief a little more artistic- sort of like the older style of physical maps National Geographic used to put out (albeit not nearly as good).

Rheia_physical.jpg

On a related note, has anyone using Mac OS had any luck recently using G.Projector? Mine crashes as soon as I open it. Have tried re-installing numerous times but it's always the same problem. Kind of a drag as I'd like to have the final product in a more aesthetically pleasing projection than equirectangular...