Terraformed Venus

[acrosome]

Here are some initial thoughts on Koppen Climates. Lines of latitude are in 15-degree increments (this is a Mercator projection that only covers to 57-degrees north and south).

Frankly, a map of biomes like the Hodridge scheme or like this is probably more practical and useful than Koppen climates, but it seems to be traditional to do the Koppen thing. I'll probably make a biome map later, and the Koppen climates will help me on that.

There are a lot of landforms that don't really have perfect analogues on Earth, so I made a lot of stuff up. For example, my huge Himalaya-like mountains are on the equator, so I used the equatorial Andes as a model for them somewhat, and made some SWAGs. (Actually they're not quite Himalaya-scale; the really tall mountains are in Ishtar.) A lot of my continents don't have a large north-south mountain range as in the Americas or Himalayan rainshadow like Asia, so I'm not sure how the east-coast and west-coast climates meet in higher latitudes without one.

My large Amazon-like Af rainforest is in eastern Ovda, since that's the only large chunk of tropical land on an east coast right on the equator. (Equatorial Phoebe is small in comparison.) I made eastern Atla somewhat similar, though.Generally, since so much of my land is in the tropics there is a LOT of Af, Am, and As.

So, I guess I'm making a jungle/desert world...

Ulfrun/Atla is a rough analogue of sub-Saharan Africa. Thus, that enormous BWh desert largely covering Zhibek and Artemis is a Sahara-equivalent. (There are no large mountain ranges to keep that desert from just cutting all the way across the continent.)

Eistla will be an Australia-equivalent. I may change the Umay-ene climate a bit and make it my Madagascar biome.

There is no good Europe-equivalent with an aberrantly high-latitude Cwa climate, unless it's Hathor and western Themis... but I was going to make Themis/Phoebe my South American biome, and make Beta my North American biome. (Ishtar is probably more like a Canada/Scandinavia bastard child.)

The only true India-like monsoon is that bit in western Thetis; the other Am climates technically meet criteria- like most of the the Amazon- but aren't the intense and brief raging torrent of the Indian Ocean monsoon.

This is all just preliminary, to help me make other decisions such as which low spots to fill as lakes and which to leave as endorheic basins, deciding where the big rivers will be, etc. Nonetheless, if anyone has any criticisms, fire away. My eyes were crossing in a lot of spots, so I'm sure that I have some egregious idiocy here, somewhere.

I'm still working on my newer maps that will show the poles as well. This is important, because there is a lot more of Ishtar down there, and that might end up being an important place. (I have to think of new names for these landforms...)

I also found GTDR data from the Magellan mission, which is topographical data on Venus. I thought I'd run it through some manipulations in Wilbur when I get a chance and see what pops out. Unfortunately, one pixel is 4.6km, so it isn't terribly detailed, and there are a lot of holes and artifacts in the data, but I still think it can help me figure some things out.

Hmm... I guess that I have a Wilbur question... given data like that can Wilbur for instance double the number of pixels (to 2.3km/px) by extrapolating elevations or somesuch? (I have yet to download Wilbur- I have to dual-boot some sort of Windows on my laptop, first.) I wouldn't mind trying to do a nice job with Wilbur on some small area, like Tellus or Eistla, or maybe Beta. (I understand that Wilbur works best on smaller scales.)

After sangi39 mentioned this inspired study on his Yantas thread I started looking around to see if there was any way I could run my world through the HadCM3L climate model, but I don't think that there is. Unless, of course, someone here happens to work for the UK Met Office or the Hadley Center...

A final point: I was going to name this world Sypherion, that being a fictional cognate of cytherean, which means "of or regarding the planet Venus." But then I found Max's map of the city of Yphyrion, and now I don't feel so clever...

[sangi39]

So I've been meaning to reply to this for about 16 days now, but luckily it's all praise, since I don't feel like I know enough to point out any errors lol. Looking at your map and the Koppen climate map for Earth, though, has really made it clear to me that my climate map for Yantas was pretty damn wrong I mean I don't have tropical rainforests at the poles, but I seem to have been overly simplistic in dealing with certain climate zones

[acrosome]

Oh, I just think that your climate map was a roughing-in, so to speak. As if you made a map with the suggested latitudes taken very rigidly, and painted in as bands, to use as a guide. I thought that's a great idea (and probably sufficient for any fantasy mapping needs). So I stole it and did something similar, but then looked at the real-world Koppen maps on Wikipedia and did some fleshing out.

I spent a lot of time obsessing over the descriptions on the Wikipedia page.

[sangi39]

Oh, I just think that your climate map was a roughing-in, so to speak. As if you made a map with the suggested latitudes taken very rigidly, and painted in as bands, to use as a guide. I thought that's a great idea (and probably sufficient for any fantasy mapping needs). So I stole it and did something similar, but then looked at the real-world Koppen maps on Wikipedia and did some fleshing out.

Huh, how very dare you I do like the whole idea-sharing thing that goes on here at the Cartographers' Guild

I spent a lot of time obsessing over the descriptions on the Wikipedia page.

Yeah, I spend a couple of days on Wikipedia, editing my climate map as I went along, but then I got annoyed and deleted the edits

[Pixie]

That's the problem with keeping the post a WIP when it comes to climate map. You spend so much time looking at it, adjusting and dealing with too many variable (rain, temperature, seasonality, high-low pressures centers, ocean currents, prevailing winds), that you end up unable to

1. explain the reasoning (if it is your map)
2. understand the reasoning and suggest improvements (if you are the lurker)

[acrosome]

As with, I suspect, most of the larval-stage cartographers who end up here I have discovered Wilbur (all hail Waldronate). I dug up some Magellan data on Venus topography and fed it through, dealt with some annoying artifacts (thanks Redrobes), and then some more artifacts, etc. Here are a few preliminary views.

First, Thetis, Ovda, and Manatum:



The snow line is set at about 14000 feet, by the way.

Next, here's one that shows that southern continent (Ishtar) and the south pole:



The pole is obvious because it was missing from the Magellan data and I had to clone some in- very inexpertly- and it shows. It's that first darker ocean basin below the high mountains on the continent.


Since I can use this data to do all sorts of neat stuff with Wilbur, I think I'll use it instead of my hand-traced version from the scanned USGS maps. I'm still trying to figure out how to export images from Wilbur. Obviously, I managed to export these, but every time I try to export an equirectangular image- or actually anything not orthographic - it gets truncated at the edges. This happens even when I set the exported image's size to my map size. Grr.

Once I deal with a bunch more little artifacts I'll start exporting it to GIMP, making sea masks, etc.

[acrosome]

Well, I've started playing with this project again, mostly puttering around learning Wilbur. I also decided to have a bash at Pixie's climate technique to see if my original thoughts jived, so I re-did my sea levels and tried to work out some better and more detailed currents:



Do you have any critiques of the currents?

One problem I have is that Venus really doesn't have continental shelves. Also, I'm particularly interested in opinions on three areas:

1. The gyre from Phoebe-Imdr-Zhibek, with the Gulf Stream hitting Imdr. This is, I suppose, my equivalent of the North Atlantic. South of that is an equatorial countercurrent, and south still more is a small gyre in the southern part of that sea. The way I have them interacting seems contrived, though I looked at the 1943 map on the Wikipedia ocean currents page and there seem to be even more dramatic currents crossing the equator in south Asia. I don't have a terrestrial model for the fact that there are a few small straits that would connect the equatorial gyre with the Beta-Ulfrun gyre. Thoughts?

2. I based the large southern-hemisphere gyre around Gula and the islands to the west of it on south Asia with all of its islands and straights, so it looks busy but I think it works. (I didn't try to map every little current in that region, just enough to fun the climate thing.) Thoughts?

3. The gyres north of Ovda and on either side of Ulfrun- am I doing that right? Or should they just be 'lobes" off of the polar currents?

And, of course, any other criticisms are not only welcome but appreciated.

Ignore the thumbnail map below- it's old, and I can't seem to figure out how to remove it.

[ascanius]

Your map is very interesting so far. There are a few areas I would have done differently but this mostly concerns micro currents among the archapelegos. I however did notic that your polar currents need some work. For example, the ocean east of Telius, that west coast should be a warm current going south, the black current lines ( >45 degrees) for both poles are the wrong direction and should be traveling west not east. One thing that helps is to overlay your hot cold pressure systems over the ocean currents to get a better idea of how things line up, ocean currents follow the high low pressure systems of the atmosphere.

I did a quick paint over to show you what I mean.



Hope that didn't confuse you.

[acrosome]

Really? I was using this and this as sources for polar currents- they show the Antarctic circumpolar currents as being eastward at 60S, though, yes, I had to try to account for the Ishtar and Lada continents being in the way. (Are you looking at subpolar currents? These are indeed westward.)

I see what you mean about the splitting of currents into a warm poleward and cold equatorward branch, especially on that second map I linked- I'll work on that. I do have something like that around Beta, though I represented it as a very weak southbound current, but you're right I could do a better job around Tellus. Clearly I shouldn't have that northbound cold current there. Mostly, though, I have to be sure that I have the direction of the circumpolar currents correct, since that will affect a lot. Yes, on Earth that splitting occurs in the southern hemisphere and the southern split joins the 60S circumpolar current, but that circumpolar current isn't a westward countercurrent- it is eastward. If I take southern Earth as my model than the currents you changed arounf Tellus should be more like the currents you added south of Beta- eastward. Or am I missing something?

Likewise, regarding the minor gyre between Xartanga and Lada- why did you switch the direction? Are you thinking of Hadley cells?

Or, maybe I should just make both of my poles more like Earth's northern pole, with smaller current "lobes" but no true circumpolar current. Is that what you mean? I'm finding the polar currents rather frustrating. But I want to get this as "good" as I can make it before I proceed further. (Thank God that since I'm working from real data I don't have to mess around with tectonics. I might have an apoplexy.)

I'll play around in GIMP when I get home.

[ascanius]

Really? I was using this and this as sources for polar currents- they show the Antarctic circumpolar currents as being eastward at 60S, though, yes, I had to try to account for the Ishtar and Lada continents being in the way. (Are you looking at subpolar currents? These are indeed westward.)

Sorry, my bad I meant subpolar. Sorry if that confused you. You have the ( <45 degree) polar currents right it's the subpolar ( > 45 degrees) currents that need work.

I see what you mean about the splitting of currents into a warm poleward and cold equatorward branch, especially on that second map I linked- I'll work on that. I do have something like that around Beta, though I represented it as a very weak southbound current, but you're right I could do a better job around Tellus. Clearly I shouldn't have that northbound cold current there. Mostly, though, I have to be sure that I have the direction of the circumpolar currents correct, since that will affect a lot. Yes, on Earth that splitting occurs in the southern hemisphere and the southern split joins the 60S circumpolar current, but that circumpolar current isn't a westward countercurrent- it is eastward. If I take southern Earth as my model than the currents you changed arounf Tellus should be more like the currents you added south of Beta- eastward. Or am I missing something?

Also look at your source image, the really detailed one (2nd one) it only shows up to 60 degrees and doesn't show the full 90 degrees lat, I think this is why your getting a little confused. Your not getting the full picture. The current does go eastwards but it's around the 45 parallel. Also note the antartic subpolar, it is more of what I was getting at.

Likewise, regarding the minor gyre between Xartanga and Lada- why did you switch the direction? Are you thinking of Hadley cells?

As to why I switched the directions, if you look at the two sources your using you will see that around 45 degrees latatude the currents travel eatward then the current splits at a landform/ice with warm moving north and cold going south. There is a long scientific reason why this happens but suffice it to say it's due to the rotation of the planet. The currents you are mapping are the surface currents wich are created by the prevailing winds caused by Hadley cells. The basic idea is closed loops, with the east/west flowing currents traveling until they are split by land then warm goes towards poles and cold towards equator.

With Xartanga and Lada the polar current travels eastward until it encounters land (the southern islands of Lada for simplicities sake) at this point the current splits with warm going towards the pole and cold going towards the equator closing the loops. That split doesn't occure prior encountering an obstical (land). {Not entirely true what you see in real life is a warm current drift north with the greatest concentration along the costs (warm current only) the cold current doesn't doe the same thing.}--> ignore this if it confuses you it's not important.

Or, maybe I should just make both of my poles more like Earth's northern pole, with smaller current "lobes" but no true circumpolar current. Is that what you mean? I'm finding the polar currents rather frustrating. But I want to get this as "good" as I can make it before I proceed further. (Thank God that since I'm working from real data I don't have to mess around with tectonics. I might have an apoplexy.)

check these out they might help you out . http://www.divediscover.whoi.edu/arc...rculation.html
http://beyondpenguins.ehe.osu.edu/fi...c_currents.jpg
http://polardiscovery.whoi.edu/antar...ulation-en.jpg


good luck