Terraformed Venus

[acrosome]

so you are going with NORTH on the bottom of the map

Yes, so that the sun rises in the east. Mind you, I'm still going to call the top of the map "north" and the bottom "south." As I mentioned before, this is to keep to familiar conventions for any notional RPG players that may eventually have characters inhabiting this world.

as to your "sealevel" and mine

Oh, so you're doing the same project? I'd be interested to see what you've got. I'm planning to fill a lot of those more dramatic inland depressions as lakes (i't a bit of a project to figure out their elevations) but I'm going to fill some of the more shallow ones. And a few will just be depressions in desert areas, though it looks like when I use your data that the desert in Artemis won't be quite as huge.

the image "16kVenusDEM.tiff" the mean average is 8065

however if you add the value "6039999" to the pixels you will get the Radius in Meters but i only scaled it to the min/max values

Yes, I think I grok that.

I did elevations the easy way: in Wilbur I did Filter>Mathematical>Span and set it from -19250 to +25683. This sets elevations in feet with the sea level as in my map above. (I'm generally a metric guy, but from all of the North American hiking I do I'm used to thinking in feet for elevations.) This is derived by the lowest point (1.8 miles below the mean radius) and the highest point (6.71 miles above the mean radius).

[acrosome]

Still slowly working. Here's some (very minimalist) labeling:

[jkat718]

Looks good, acr! I particularly like the coloring, both for the labels and for the terrain itself.

[acrosome]

Looks good, acr! I particularly like the coloring, both for the labels and for the terrain itself.

The terrain is all Wilbur at this point, I'll pass the praise on to Waldronate. Well, except for the below-sea-level basins, which I have temporarily filled with that psychedelic green tint. I'm no artist. This is more an exercise in worldbuilding for me. As I slowly figure out GIMP I'll keep trying to makle it prettier, but that's after I've done the worlbuilding. I need know where it rains, for instance, before I can tint the vegetation, decide if a basin is a lake or a salt flat, etc.

Regarding the labels- I finally sat down and figured out how to text-to-path in GIMP, so I'm playing around with it a bit. For that matter, I think that I finally understand layer masks. Woop!

[acrosome]

Y'know, for a forum about maps the 4MB upload restriction is kind of draconian...

So, working with johnvanvliet's (much better) data, here are some ideas for currents:



Fire away- critiques welcome.

Ascanius- I tried to make the wide 45-60 degree eastward current discrete from the westward subpolar current that we were getting wrapped up about. I need to better define where the cold currents drop out of the poles.

My oceans are broken up much more than on Earth, with many islands, so there there are a lot of meandering warm currents that I modeled on the Southeast Asian currents.

With the new data (and thus new coastlines) there is no longer a Gulf Stream hitting Imdr. Instead, it looks like northern Themis has one.

[ascanius]

Looks good, I like this version a lot more the landmass don't have those weird extreme rifts/ravines any more. The colors and everything else also look a lot clearner. As for currents everything looks good but the Russalka gulf and Himenoa sea would probably have equatorial currents like those in the center of the map.

I'm currious how high are the mountains in Ovda and Ishtar. I could see Ishtar being covered in frozen carbon dioxide at the heigher elevations. I think it would be cool to see some of the mountain ranges from the planet surface.

[acrosome]

The Ovda and Thetis mountains top out at ~18,000 feet and the Maxwell Montes in Ishtar top out at ~25,500 feet with this sea level. So the former are Alp equivalents, and the later are Himalaya equivalents.

The rifts and ravines are still there- I just colored them in bright green until I can work out climate and decide which are going to be dry basins and which will be lakes or seas, etc. There will be a particularly large one in western Aphrodite. But I've been experimenting and I'll probably fill all of the lesser basins. I've gotten facile enough with Wilbur that I'm geeting reasonably good looking results after some basin fills and a few gentle erosion cycles.

But, damn, you struck right to a couple of areas that gave me heartburn- Russalka and Hinemoa. In short, I just reviewed that 1943 map on Wikipedia and I see that you are right. I'll tweak those. Hinemoa is a bit of a tougher nut, though- there is no Earth equivalent for an enclosed sea like that on the equator. Hinemoa is going to be weird, not least because my research reveals that (small-m) mediterranean seas' currents are often driven more by differences in salinity than by wind. So I'm not going to feel too put out if it doesn't make total sense viz. winds.

What do you think of the Undine Sea connecting Hinemoa to Guinevere? I'm having trouble wrapping my head around that one.

I've also tweaked a few minor currents in the Lada Sea since I posted that last map, and added a few more minor currents. Working out the high and low pressure zones and winds is also odd, since my largest continent is right on the equator and there is no equivalent of Siberia to make a nice, strong low. Ishtar probably acts more like Antarctica than like Siberia.

EDIT---

How does this look:



Doing the initial work on weather, here is my great conundrum: the ITCZ. I have to decide whether or not it flops back and forth to the north and south of the equatorial mountains in Aphrodite, or if it stays to one side. Any thoughts? If it ever runs north of them that'll have dramatic effects mitigating against a huge desert in the Artemis Chasma region as I had on my earlier climate map. I have to admit I kind of liked the megadesert, but having the ITCZ flop around that much would make for some interesting weather. Maybe I could waffle and say something like "The ITCZ flopping north of the mountains happen about once a decade, and has profound effects when it does" or somesuch.

[acrosome]

I've been fighting a lot with the high and low pressure zones. I tried a new technique:



Here are the winds:



Inspiration found here.

Criticisms?

Frankly, none of the landmasses at about 30 degrees are very large, so they shouldn't have very strong summer lows- certainly nothing like the monstrous Siberian low. So I think their effect will be small. To show this weakness it might be best to represent them as just not high. This is a bummer, because I wanted a true monsoon somewhere. Maybe in that gulf between Thetis and Ovda, on the southern shore of Aphrodite? It would be an odd April/May monsoon...

I also think that with Pixie's method you have to think of the ITCZ and the polar fronts as standing low-pressure zones. Thus, think like both poles are high pressure, with winds moving toward the polar front. I'll change that.

[ascanius]

Hey. I think you figured out the currents.

I don't understand what your doing with the subtropical high pressure systems, I think your using two colors to show strength right?

looking at your map I can see venus would be a great vacation spot with a lot of tropics along the ocean. Too bad it's extreamly hostile in real life.

Cant wait to see how you do with the climates.

Edit: meant to delete that sentence about Beta.

[acrosome]

Regarding colors: yes, darker shades of yellow for higher highs, darker shades of green for lower lows, etc. (And, yes, I got the poles wrong- they should be highs. When I get home I'll post the updated maps.)

You say that Beta would have a low in both seasons? How do you figure? Geoff's cookbook (and other sources) mention continental highs in winter. Did I miss something subtle?

And, yes, it's like someone shoved Asia southward until it sits on the equator...