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[Daistallia]

[su_liam]

The low axial tilt also means that you will have a wider temperature spread between equator and poles.

Obliquity involves a straight trade-off between spatial and temporal variation. More tilt -> (more pronounced seasons; less difference in average temperature by latitude). Less tilt -> (Less seasonal variation; greater difference in average temperature by latitude).

High eccentricity would lead to more temporal variation without the more equal distribution of heat across the surface.

A large hydrospheric fraction, which you have, will moderate temperature variations both in time and in space.

Thinking about the rotation rate. A fast rotation will lead to much more pronounced east-west circulation and weaker latitudinal heat transfer(more variation in temperature with latitude)(This much I know for sure.) I don't know any numbers on this as I haven't been able to find any modelling data on circulation vs. rotation rate. I believe that the three-cell circulation will still hold at a 60 hour day, though it may be less pronounced(not totally certain about this). Number of cells will probably be a function both of the strength of the Coriolis effect and the depth of the atmosphere(atmospheric depth would be proportional to surface pressure divided by gravity).

Another effect of slow rotation will be increased diurnal variation. Everywhere, though less pronounced nearer the poles and greater nearer the equator.

Higher greenhouse effect will tend to even out temperature variations on all scales, both spatially and temporally. For a given atmospheric composition, the greenhouse multiplier should be proportional to the mass of atmospheric gases over a unit of surface area, though there might be an exponent applied to that. So greenhouse effect would be roughly surface pressure divided by gravity multiplied by some factor dependent on composition( P/g*k(composition) ). The average surface temperature would be related to the blackbody temperature, thus: Tsurface = (1 - Albedo)*Tblackbody*P/g*k(composition). Blackbody temperature would be related to the planet's orbital distance(R, in a.u.'s), and the star's luminosity(L, in Solar luminosities), thus: Tblackbody = (L / R)^0.25. Figuring out how to work that out as it varies along an eccentric orbit is left as an exercise for the poor reader .

Thus, as Buffy said, endeth the lesson. Hopefully this was of use...

[Daistallia]

See below.
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[Daistallia]

See below.
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[su_liam]

It looks like you have high pressure over land in summer. Those really should be lows.

The land heats up faster in summer than the water causing the air to rise. The heavier, cooler maritime air rushes in to fill the reduced pressure, "void."

You also seem to be showing the ITCZ as high pressure.

The STHZ appears to be properly high pressure, so it doesn't look like you can just relabel the pressures and treat red as low pressure. Also your polar regions should generally be high pressure. Aaaand, your winter hemispheres(south in summer, north in winter) seem way way too homogeneous. Continental regions should have pronounced highs in winter to go with the summer lows.

Other than that its a very nice map. Given the pressures as you have them here, your surface winds look proper, too. This style is very polished and professional-looking if you work out your pressures.

[Daistallia]

[su_liam]

Still a beautiful map for its purpose. Get those pressures ironed out and they'll hang it in a gallery. Behind a weatherman .

One last note, thus exhausting my intellect: the top and bottom lines look like they should be the polar fronts. If so, those should be lows. And if they aren't the PF... they should be.

My last couple terms in college were pretty intensive on climatology, hydrology and paleoclimatology, so most of this stuff was pounded into me and is still fresh. Freshish.

[Daistallia]

I followed the instructions here.

(Edit: Or maybe I should say screwed up. )
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[Daistallia]

See below.
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[su_liam]

Looks promising to me.

Since I don't have a good memory of your world's geography, it would be helpful to have a layer with the outlines of landmasses. I'm firing up Photoshop, now, to see how this fits your land.

So far so good.

[Daistallia]

[Daistallia]

Latest versions:
"Summer":


"Winter":

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[su_liam]

Is there any way you could put up your previous version without the underlying surface detail. I was gonna try something(see what you thought), but I took to long with the kids etc?

I created an otherwise transparent outline of your continents(teal and khaki areas), simplified the outlines and I was about to lay the result over your pressure map.

I think the result would have more clear than the straight overlay you used. It would have been much like these.

Of course this is your map, so I don't intend to bogart it .

EDIT: That came off a little Gimmee!. You have the makings of an excellent map here. Otherwise I'd say good enough as-is, and shut up.

[Daistallia]

[su_liam]

Oh well. Here's my attempt at a summer map. Notice my crappy attempt at a gradient.

This requires enough effort that I think I need to get to work applying this to Sadwillow. On the one hand, a lot of effort; on the other hand, really good results.

I modified Anguipes' tutorial a bit. I started with the 128-grey then, without looking at landshapes, I jotted in black over the ITCZ and polar front with a large diffuse brush in a low opacity. Then I similarly blotted in black over the STHZs and poles. I called this layer Summer and made a copy which I called Winter for later.

Next, I made the shorelines visible. I used the smear brush at 90% strength to push the low pressure associated with the ITCZ north over land areas.

Unless land areas are large(you don't really have anything like that here), most of your attention will go to water areas. I used a large diffuse brush on low opacity to build up the white areas over the northern oceanic STHZ. Mostly it will expand to the north, only a very little towards the ITCZ.

Once the summer hemisphere oceanic high pressure cells are blobbed in, I added a little bit of low pressure over the continental area.

This map doesn't have a lot going on in the southern hemisphere, so I just built up the low pressure over the midlatitudes in open-sea areas and enhanced and enlarged the antarctic high pressure cell.

Due to the absence of disruptive land masses in the southern hemisphere, this map doesn't give much of a notion of how I would deal with complex winter circulation. As a hint till I get something together: the (55º N -ish)polar front will expand over the ocean into a huge low pressure cell(almost to the tropics at the southwest corner and up to the arctic circle in the northeast), the oceanic high pressure cell associated with the STHZ will shrink to a nubbin in the southeast corner of the oceanic region(very close to shore, centered at about 25º N).

Clearly, I need to find the site where I downloaded all of my wikipedia and ESRI gradient files.

EDIT: Never destroy anything until you are completely done with your project. Burn it to CD, if you have to. IME things you delete always, always, come back to bite you on the ass. Not a criticism so much as a kindness...

EDIT2: I didn't post the freaking image. What a twit...!


Blue is low pressure, red is high pressure. The graticule is a 15º grid. If you look closely, you'll see a red color to the equator line, a gold color to the 30º N/S lines(approximating the STHZ), and a green coloration to the 60º N/S lines(a very loose approximation to the PF). I think the shore lines are fairly obvious.

EDIT... um... N: Now the winter. I did an experiment, here, and I don't think I'll repeat it. Intentionally...



EDIT. again. Reversed my color scheme description. I usually use red for low pressure, 'cause it tends to follow higher temperature(loosely), and blue for high pressure for the same reason, but I had reversed my gradient to follow the standards in the post I was working off of.

[Daistallia]

[su_liam]

[Daistallia]

The (hopefully!) final versions of the pressure maps, maontains and highlands (heh -typo left in for humor's sake ), and a couple of variations/cleanups of the main map.

Summer:


Winter:


Mountains and Higlands (scaled down)


Mountains and Higlands (full sized version)

(And just for reference, the plates map.)

Main Map Version 2a

Main Map Version 2b
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[Daistallia]

I've gone with a shorter day and year than the first set, and a more clearly very near to Earth set up, aside from being a cooler star and the shallower tilt. Hopefully this looks better than the first data set. (The radius was set to make the map easy to scale! )

[Daistallia]

And now we have Köppen climate maps...




(Note that not all the climates on the key are found on the map.)

Large scale map:
http://i709.photobucket.com/albums/ww98/gauzstien/climate/gwazkoppenmap.jpg
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[su_liam]

Comparing your map to Earth.


By null at 2010-09-04

I think you may have overestimated the extent of your cold desert climates. The BWh and BSh I'm cool with, but I expect more of your BWk to go to more southerly D climates, a few areas of BSk and patches of BWk in rainshadow areas. The somewhat more southerly extent of the D climates I could lay at the feet of that lower axial tilt, although I expect the continental climates to be less extreme given the low seasonality and small size of the continent.

The continents are actually smaller than they look because of the smaller size of the planet overall.
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[Daistallia]

Ooh, thanks for that. I've actually got a second version I haven't posted yet, but I hadn't thought of putting it through that program. Excellent idea.
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