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Porklet
07-06-2011, 01:03 PM
I am trying to work out the climate of the world that I am working on. While climatology interests me I still don't know much about it. If some of you could take a look at what I have done it would be greatly appreciated.

Using the conic graticule provided by Hai-Etlik I have determined the relative air currents, and with the help of Hawksguard and Juggernaut1981 my mountains are in place. I have included a map with wind currents, rain shadows, and areas where deserts should occur. Or at least I believe they should occur.

The ranges are labeled 1-7 (with 1 being the oldest mountain range). 1-4 are ancient, 5a-5c are middle-aged, and 6 & 7 are the youngest (and the highest with 6 being massive). I do know that mountains force air upwards, cooling the air, and causing precipitation, but that is where my knowledge ends.

The yellow areas are proposed deserts, the red areas are rain shadows created by the mountains, and the red 23 near the center is the 23rd parallel. Any area below this line is going to receive rainfall to varying degrees, and in many places excessive rainfall. The deserts are not in their final form. They are approximate and representative.

If you have any ideas about what I have done so far I would to hear it. I also have a few specific questions:

1. When mountains force precipitation can the water fall in catchments and create rivers on the opposite side (where the shadow lies)?
2. Do you see any area where the weather might be particularly volatile?
3. Hurricanes will form in the southern oceans, but at what latitude do they usually form? Will hurricanes/typhoons cross the equator?

36918

Again I could not insert the image online. I don't know why. Sorry about that.

Once I determine the rainfall and wind I will begin work on the water currents and distribution. I didn't want to do too much at once. Thanks in advance for any help.

jbgibson
07-06-2011, 07:24 PM
Hey, Porklet. I'm no climatologist, nor do I play one on TV. Nonetheless, like you, I'm interested. A few questions that may steer your wind planning & climates: what's your axial tilt? Is it the 23 degrees you refer to as a break point? Does your world have enough orbital eccentricity to accentuate or mute the summer/winter effects from tilt? Are these the only landmasses?

I have started a tutorial ( I need to apologize to Slipguard every time I mention it til I get it finished :-) ) on figuring wind and ocean currents. (http://www.cartographersguild.com/showthread.php?11964-Where-does-the-wind-blow) Some others here have written up how they figured things - in particular I recall seeing Naeddyr's (http://www.cartographersguild.com/member.php?2491-Naeddyr) amazing Ysi Earth II (http://www.cartographersguild.com/showthread.php?5341-Ysi-Earth-II-by-Naeddyr) - that's the Featured Map page for it; follow the link to the WIP thread. It is an amazing stream-of-cartography lesson. Note that in the heat of battling climate issues, Naeddr swore off ever doing another such thoroughly rationalized climate map.... don't pay that too much heed.

A significant issue in figuring rain shadow effects is that with an axial tilt, those nice generalized wind patterns are going to oscillate north-south between summer and winter. So really, the only "reliably shaded" area would be one where both summer and winter general winds go the same way. Or same-ish way... Too, you won't get neat bands, unless you have a cue ball of a planet (or a mostly gaseous one - see Jupiter's and Saturn's banding). Instead, you get general highs and lows, with attendant clockwise and counterclockwise flow (flipping once you cross the equator) (and here one means "heat equator", roughly the latitude at which the sun at noon is straight overhead) (BUT strongly modified N-S by large land and sea masses). Also, any such pattern is the general airflow. There'll be plenty of weather activity that differs from time to time.

Got a used bookstore nearby? Grab a college climatology / weather textbook. A well-spent five to ten bucks. There's a wealth of info on the web too, but it helps to know the terms to search for. There's NOT many treatments of generalized arbitrary worlds - most understandably are Terra-centric.

"Most tropical cyclones form on the side of the subtropical ridge closer to the equator, then move poleward past the ridge axis before recurving into the main belt of the Westerlies" ( Wikipedia (http://en.wikipedia.org/wiki/Tropical_cyclone)) . Here's a map of one of my worlds showing general cyclone tracks.
36923
That planet has its own wiki (many people's work!) where I have a Cyclone distribution article (http://worldspinner.net/worldofaurora/wiki/index.php?title=Tropical_Cyclone_Distribution) that might give you ideas. A similar coverage of Earth's cyclones (http://www.mapsofworld.com/hurricane/distribution/spatial-distribution.html) shows graphically the curving effects and where they spawn. You can see they just don't cross the equator.

So that's Q3. Q2 I'd wait to figure til you work out likely (or just plausible - there ARE no climatology police here :-) ) summer/winter patterns. Q1 - yep, you could get rain dumped on the upwind side of a range, and some of the rainfall running "around the corner" across the resulting dryer area, or maybe through a pass in the range. Remember if there's much of a cleft in a barrier range, the wet air will seep through too, muting the rain shadow effect. Or a continent-spanning river (cf: Nile) could catch rain in a wet area and run across unrelated dry areas.

Have you read Redrobes' river location tutorial (http://www.cartographersguild.com/showthread.php?3822-How-to-get-your-rivers-in-the-right-place)? Ascension put a mini-tutorial in a post in a thread about where to place stuff (http://www.cartographersguild.com/showthread.php?14237-Advice-on-placing-elements-in-a-world-map&highlight=climate). njordys put up a nice climate zone / rainfall map pair (http://www.cartographersguild.com/showthread.php?12974-Deserts&p=138797&viewfull=1#post138797) - you can infer the prevailing winds (http://en.wikipedia.org/wiki/File:Map_prevailing_winds_on_earth.png), but you need a January (http://etc.usf.edu/maps/pages/3000/3024/3024.htm) vs. July (http://etc.usf.edu/maps/pages/3000/3025/3025.htm) pair, which by the way shows what drives the ocean currents (http://etc.usf.edu/maps/pages/3000/3023/3023.htm). Here's a prettier view (http://etc.usf.edu/maps/pages/4700/4754/4754.htm) - kind of the average of those seasonal prevailing winds. If you're used to thinking in terms of high and low pressures and what they do to weather, this pair (http://etc.usf.edu/maps/pages/10000/10031/10031.htm) are useful. The rules of thumb about what forms over a large-ish landmass or large-ish ocean in which season, will let you guess something like this for your world. Reason I asked if these were the only landmasses is that the behavior over an uninterrupted hemisphere-size ocean would lean more toward the ideal than our "continental high in winter" thought.

Not complex enough? Well, those are the surface winds. Another big driver in climate & weather is the jet streams, as you can see in many weather maps. They're pretty dynamic, so maybe less use in predicting average patterns. But if you're using your world for anything other than a pretty map, knowing when and where the storms run could be hugely important. this site (http://www.fas.org/irp/imint/docs/rst/Sect14/Sect14_1c.html) has jetstream maps down at the bottom - there's more golden info all up and down it too. Such as a clue why some latitudes have much more of wet season / dry season, than what we temperate-zone folks think of as summer and winter. Then once you get all that air and water moving, it transports the very heat that drove the motion in the first place. THe mundane example is the 'abnormal' warmness of the northeast Atlantic thanks to the Gulf Stream. Generalized, that becomes a world map showing where heat gets shoved around (http://etc.usf.edu/maps/pages/8000/8089/8089.htm).

Waldronate posted a couple of awesome links (http://www.cartographersguild.com/showthread.php?11329-Ocean-Current-and-Climate-Modeling&p=122479&viewfull=1#post122479) that go into more detail about the other factors driving currents, including deep-water ones.

Yeah, the forum's image-attacher thingamwhoozit sometimes glitches. For me a link is fine, 'stead of a thumbnail.

That's a decent progression of rain & wind, then currents & climate. Just be willing to iterate it a bit, as for instance the ocean currents influence the temperatures which goes back and affects the rainfall, etc. Or stop the thinking at any point you like and just MAP.... it's all your set of judgements, and the rare person who decides to nitpick your exact climate can feel free to redo it to suit himself :-). Me; I look forward to seeing your process in action, so do please keep us posted.

Porklet
07-06-2011, 09:00 PM
Hey, Porklet. I'm no climatologist, nor do I play one on TV. Nonetheless, like you, I'm interested. A few questions that may steer your wind planning & climates: what's your axial tilt? Is it the 23 degrees you refer to as a break point? Does your world have enough orbital eccentricity to accentuate or mute the summer/winter effects from tilt? Are these the only landmasses?

I have started a tutorial ( I need to apologize to Slipguard every time I mention it til I get it finished :-) ) on figuring wind and ocean currents. (http://www.cartographersguild.com/showthread.php?11964-Where-does-the-wind-blow) Some others here have written up how they figured things - in particular I recall seeing Naeddyr's (http://www.cartographersguild.com/member.php?2491-Naeddyr) amazing Ysi Earth II (http://www.cartographersguild.com/showthread.php?5341-Ysi-Earth-II-by-Naeddyr) - that's the Featured Map page for it; follow the link to the WIP thread. It is an amazing stream-of-cartography lesson. Note that in the heat of battling climate issues, Naeddr swore off ever doing another such thoroughly rationalized climate map.... don't pay that too much heed.

A significant issue in figuring rain shadow effects is that with an axial tilt, those nice generalized wind patterns are going to oscillate north-south between summer and winter. So really, the only "reliably shaded" area would be one where both summer and winter general winds go the same way. Or same-ish way... Too, you won't get neat bands, unless you have a cue ball of a planet (or a mostly gaseous one - see Jupiter's and Saturn's banding). Instead, you get general highs and lows, with attendant clockwise and counterclockwise flow (flipping once you cross the equator) (and here one means "heat equator", roughly the latitude at which the sun at noon is straight overhead) (BUT strongly modified N-S by large land and sea masses). Also, any such pattern is the general airflow. There'll be plenty of weather activity that differs from time to time.

Got a used bookstore nearby? Grab a college climatology / weather textbook. A well-spent five to ten bucks. There's a wealth of info on the web too, but it helps to know the terms to search for. There's NOT many treatments of generalized arbitrary worlds - most understandably are Terra-centric.

"Most tropical cyclones form on the side of the subtropical ridge closer to the equator, then move poleward past the ridge axis before recurving into the main belt of the Westerlies" ( Wikipedia (http://en.wikipedia.org/wiki/Tropical_cyclone)) . Here's a map of one of my worlds showing general cyclone tracks.
36923
That planet has its own wiki (many people's work!) where I have a Cyclone distribution article (http://worldspinner.net/worldofaurora/wiki/index.php?title=Tropical_Cyclone_Distribution) that might give you ideas. A similar coverage of Earth's cyclones (http://www.mapsofworld.com/hurricane/distribution/spatial-distribution.html) shows graphically the curving effects and where they spawn. You can see they just don't cross the equator.

So that's Q3. Q2 I'd wait to figure til you work out likely (or just plausible - there ARE no climatology police here :-) ) summer/winter patterns. Q1 - yep, you could get rain dumped on the upwind side of a range, and some of the rainfall running "around the corner" across the resulting dryer area, or maybe through a pass in the range. Remember if there's much of a cleft in a barrier range, the wet air will seep through too, muting the rain shadow effect. Or a continent-spanning river (cf: Nile) could catch rain in a wet area and run across unrelated dry areas.

Have you read Redrobes' river location tutorial (http://www.cartographersguild.com/showthread.php?3822-How-to-get-your-rivers-in-the-right-place)? Ascension put a mini-tutorial in a post in a thread about where to place stuff (http://www.cartographersguild.com/showthread.php?14237-Advice-on-placing-elements-in-a-world-map&highlight=climate). njordys put up a nice climate zone / rainfall map pair (http://www.cartographersguild.com/showthread.php?12974-Deserts&p=138797&viewfull=1#post138797) - you can infer the prevailing winds (http://en.wikipedia.org/wiki/File:Map_prevailing_winds_on_earth.png), but you need a January (http://etc.usf.edu/maps/pages/3000/3024/3024.htm) vs. July (http://etc.usf.edu/maps/pages/3000/3025/3025.htm) pair, which by the way shows what drives the ocean currents (http://etc.usf.edu/maps/pages/3000/3023/3023.htm). Here's a prettier view (http://etc.usf.edu/maps/pages/4700/4754/4754.htm) - kind of the average of those seasonal prevailing winds. If you're used to thinking in terms of high and low pressures and what they do to weather, this pair (http://etc.usf.edu/maps/pages/10000/10031/10031.htm) are useful. The rules of thumb about what forms over a large-ish landmass or large-ish ocean in which season, will let you guess something like this for your world. Reason I asked if these were the only landmasses is that the behavior over an uninterrupted hemisphere-size ocean would lean more toward the ideal than our "continental high in winter" thought.

Not complex enough? Well, those are the surface winds. Another big driver in climate & weather is the jet streams, as you can see in many weather maps. They're pretty dynamic, so maybe less use in predicting average patterns. But if you're using your world for anything other than a pretty map, knowing when and where the storms run could be hugely important. this site (http://www.fas.org/irp/imint/docs/rst/Sect14/Sect14_1c.html) has jetstream maps down at the bottom - there's more golden info all up and down it too. Such as a clue why some latitudes have much more of wet season / dry season, than what we temperate-zone folks think of as summer and winter. Then once you get all that air and water moving, it transports the very heat that drove the motion in the first place. THe mundane example is the 'abnormal' warmness of the northeast Atlantic thanks to the Gulf Stream. Generalized, that becomes a world map showing where heat gets shoved around (http://etc.usf.edu/maps/pages/8000/8089/8089.htm).

Waldronate posted a couple of awesome links (http://www.cartographersguild.com/showthread.php?11329-Ocean-Current-and-Climate-Modeling&p=122479&viewfull=1#post122479) that go into more detail about the other factors driving currents, including deep-water ones.

Yeah, the forum's image-attacher thingamwhoozit sometimes glitches. For me a link is fine, 'stead of a thumbnail.

That's a decent progression of rain & wind, then currents & climate. Just be willing to iterate it a bit, as for instance the ocean currents influence the temperatures which goes back and affects the rainfall, etc. Or stop the thinking at any point you like and just MAP.... it's all your set of judgements, and the rare person who decides to nitpick your exact climate can feel free to redo it to suit himself :-). Me; I look forward to seeing your process in action, so do please keep us posted.

So much respond to. Thanks for the feedback. I'll take them in order.

The axial tilt is identical to Earth's. I wanted to create a believable natural world. So I stole from nature. Everything is proportionally the same but halved. The world is 12,000 miles in diameter around the equator, etc. The 23rd parallel refers to the area furthest from the Equator where there is above average rainfall year round, for the most part. I got my information from this site, http://www.blueplanetbiomes.org/planet.htm, which broke down the different climates of the world. It didn't go into weather patterns, depressions, or even water currents. Except when referring to a specific climate that relied on, for example, westerly winds. In answer to your second question, it is the only known land mass. I want to leave it open, but it is the only land mass in this hemisphere.

Nice work. I didn't realize the winds moved that way based on High and Low Pressure. I got the wind patterns from the free excerpt from "A Magical Society: Guide to Mapping" by Expeditious Retreat Press. It's simplistic, but it suits my purpose. I had no idea that the wind patterns oscillated between the Winter/Summer. I am going to have to study this plethora of information you have given me. I have downloaded the images you were using in your tutorial post along with the Desert/Rainfall pair you linked to.

I had previously downloaded Redrobe's tutorial, and I am going to move onto rivers, lakes, and ocean currents following this stage. Actually, it occurs to me that ocean currents are probably integral to this stage. I am going to have to look into that as well.

Oscillating air currents, high and low pressure areas, and jet streams; dear lord what I have I done?

I am going to have to take all of this in over the next couple of days. I appreciate all of the links and info; especially your own hurricane charts. Thanks again for the info. Will post soon.

Master TMO
07-06-2011, 09:07 PM
Bookmarking this thread for use later on! :D

Hawksguard
07-07-2011, 12:09 AM
Everything is proportionally the same but halved. The world is 12,000 miles in diameter around the equator, etc.

Sorry I don't have time to comment on the entirety of your post atm. Loos like JB has some awesome info for you. However, the statement above kind of flashed red when I read it. First off, I'm assuming you meant 12,000 miles in circumference around the equator, not diameter, since you said you were halving things. A planet with 1/2 the circumference of the Earth is going to have about *1/8* the volume of the Earth (and assuming it is proportional, about 1/8 the mass), which would give it physical characteristics much closer to Mars than Earth. If this is a naturally evolved planet, a lot of your breathable gasses aren't going to be gravitationally bound to your planet, and you're going to wind up with something tenuous at best. Of course, you could say that your smaller planet has a mass similar to Earth's, but then, all that extra metallic iron in your planet's mantle is going to wreak havoc with your magnetosphere, turning everyone's brain synapses into a fine paste. ;) Your planet would also rotate somewhat more slowly since it doesn't need to go as far to get that 24 hour day, resulting in much decreased wind patterns, weather, and climate. Also, I'm not sure a lot of Earth climatology models would be comparable with a planet with that much decreased surface area.

When I was designing my world, I hit a lot of walls as well when trying to keep it habitable and similar to Earth and yet, at the same time, throw some variety in there. I managed to acquire a lot of leeway in making it a world terraformed by a highly advanced culture (with remnants of their terraforming technology still in place and functioning), but every time you tweak something it has the potential of throwing a lot of other things out of balance. For example, by making a planet where life had never evolved naturally on its own, I inadvertently deprived my developing civilizations of the primary fuel source (fossil fuels) that got humans through the industrial revolution. Whoops.

Check out this list (http://en.wikipedia.org/wiki/Planetary_habitability) of things needed to have a stable, habitable planet.

jbgibson
07-07-2011, 02:51 AM
Ooooo, cool caveats, Hawksguard. Porklet, if you need things to be AS THOUGH the circumference were half that of Earth, how about if you leave it earth-sized, and make your people (and critters, and plants) twice the size? :-) I mean, that has its own problems, but at ~6ft tall humans aren't at the theoretical limit of bio structures, right? Time could be local, with twenty-four (or whatever desired) parts of whatever the rotation period needs to be.

Or hmmmm..... core has more lead than iron (pick magnetically inert heavy-ish metal), atmosphere is denser than earth's, yadda, yadda. Or it outgases nitrogen and oxy at a rate that makes up for increased loss from somewhat lower grav..... there's AlWaYs rationalizations, even if they may not be proven rational, ifyaknowwhattImean.

What have you done? Created parameters for a delightfully complex puzzle. If it gets to be a harder puzzle than you wanted, cheat. Or redefine success. :-)

Hai-Etlik
07-07-2011, 06:17 PM
Or hmmmm..... core has more lead than iron (pick magnetically inert heavy-ish metal), atmosphere is denser than earth's, yadda, yadda. Or it outgases nitrogen and oxy at a rate that makes up for increased loss from somewhat lower grav..... there's AlWaYs rationalizations, even if they may not be proven rational, ifyaknowwhattImean.

Iron is the heaviest thing that there's enough of as it's the heaviest product of stellar nucleosynthesis. Heavier elements require more energetic and rarer processes to form, like supernovae and particle accelerators.

Porklet
07-07-2011, 07:20 PM
Sorry I don't have time to comment on the entirety of your post atm. Loos like JB has some awesome info for you. However, the statement above kind of flashed red when I read it. First off, I'm assuming you meant 12,000 miles in circumference around the equator, not diameter, since you said you were halving things. A planet with 1/2 the circumference of the Earth is going to have about *1/8* the volume of the Earth (and assuming it is proportional, about 1/8 the mass), which would give it physical characteristics much closer to Mars than Earth. If this is a naturally evolved planet, a lot of your breathable gasses aren't going to be gravitationally bound to your planet, and you're going to wind up with something tenuous at best. Of course, you could say that your smaller planet has a mass similar to Earth's, but then, all that extra metallic iron in your planet's mantle is going to wreak havoc with your magnetosphere, turning everyone's brain synapses into a fine paste. ;) Your planet would also rotate somewhat more slowly since it doesn't need to go as far to get that 24 hour day, resulting in much decreased wind patterns, weather, and climate. Also, I'm not sure a lot of Earth climatology models would be comparable with a planet with that much decreased surface area.

When I was designing my world, I hit a lot of walls as well when trying to keep it habitable and similar to Earth and yet, at the same time, throw some variety in there. I managed to acquire a lot of leeway in making it a world terraformed by a highly advanced culture (with remnants of their terraforming technology still in place and functioning), but every time you tweak something it has the potential of throwing a lot of other things out of balance. For example, by making a planet where life had never evolved naturally on its own, I inadvertently deprived my developing civilizations of the primary fuel source (fossil fuels) that got humans through the industrial revolution. Whoops.

Check out this list (http://en.wikipedia.org/wiki/Planetary_habitability) of things needed to have a stable, habitable planet.

I did mean circumference, but since it won't work as I envisioned I am not opposed to doubling the size. When I started this thing, o so many years ago, it was 1,000 miles by 1,500 miles, and it only included the mainland and few small islands. I've come this far, what's another 3,000 miles? The distance from the equator to either pole is roughly 6,000 miles, correct?

I am working with a 3,000 x 3,000 pixel map that stretched from 75 degrees N to 15 degrees S (or 90 degrees). It was one mile per pixel, but at 2 miles per pixel the distance from the top of the map to the bottom following the same longitude should be 6,000 miles. Is that right?

Since I stared recreating this world it has grown and changed a lot. I'm OK with a bit more.

I am still reading thru the info JB provided, and I'm deciding how far I want to take this. The Summer/Winter wind patterns, upper ocean currents, hurricane activity, rainfall, regional climate, and curious or unusual weather patterns are pretty much the limit. I am looking into the H/L Pressure systems, jet stream, and deep ocean currents. I am redefining the Rain Shadows based on JB's new information. I will post tonight.

EDIT: It might be childish, but I can't help but chuckle when I read the word panspermia in the article you referenced above. It happened again.

Porklet
07-07-2011, 07:28 PM
Ooooo, cool caveats, Hawksguard. Porklet, if you need things to be AS THOUGH the circumference were half that of Earth, how about if you leave it earth-sized, and make your people (and critters, and plants) twice the size? :-) I mean, that has its own problems, but at ~6ft tall humans aren't at the theoretical limit of bio structures, right? Time could be local, with twenty-four (or whatever desired) parts of whatever the rotation period needs to be.

Or hmmmm..... core has more lead than iron (pick magnetically inert heavy-ish metal), atmosphere is denser than earth's, yadda, yadda. Or it outgases nitrogen and oxy at a rate that makes up for increased loss from somewhat lower grav..... there's AlWaYs rationalizations, even if they may not be proven rational, ifyaknowwhattImean.

What have you done? Created parameters for a delightfully complex puzzle. If it gets to be a harder puzzle than you wanted, cheat. Or redefine success. :-)

I'm OK with a larger earth like planet. As I was designing the land masses (even at double the distances) I had found that over the course of 2,000 years (roughly) my cultures would become a lot more intermingled than I had originally anticipated. I don't mind that, but I want a majority of it to happen in story or game. With more land there's more elbow room, and "we got ta got ta git cha some elbow room," to quote Schoolhouse Rocks.

I'm still looking over the vast amount of information you provided. Will post tonight.

One question, when the wind patterns reverse themselves from winter to summer and back again (if I am understanding this correctly) I am sure they don't just wave at each other and start running back the way they came, right? Is there a gentle transition?

Porklet
07-08-2011, 12:07 AM
I am going to have to take this one step at a time. There's just too much information to digest all at once. I am starting with the wind.

Using JB's Megalaos Summer pattern (reposted below for convenience) I applied it to my conical map. My map is also a Summer Map. I had to estimate the latitudes extending out from the center, because I didn't feel like drawing curved lines for the next two days. The red line is the "solar equator" at 23 degrees (measured). Again, I didn't extend it because it would have to curve. The Horse Latitude (normal 30) and the Subpolar Low (normal 60) are at 53 degrees and "off the map". I didn't know what changes that last part would make so I just went with it.

The map is cluttered with wind arrows, and I just started plunking them down with only the basic framework of JB's pattern in mind. I wasn't sure how much effect mountains would have on the wind currents. The shifts due to mountain ranges might be exaggerated. I have not included Tradewind references, calms, or hurricane breeding grounds, yet. I have specific questions below:

1. How much do mountains affect the wind currents? Can they alter their path? Does it differ based on elevation?
2. Is there less wind effect over land? (I noticed on some of the real world wind maps circa 1901 provided by JB in his original post that there are a lot less arrows over dry land).
3. What creates a Calm or Doldrum? I have noted their positions on maps of our earth, but I can't figure exactly why they occur.

This is only a first draft, and it included all of my thoughts on the subject (thus the massive collection of arrows). I am going to clean it up, but I need to know if I'm on the right track. Once I get this completed I'll move on to the Winter Map, place Doldrums, etc. First things first, for the love of god help me!

36939

36940

P.S. I am a little disappointed no one got my "How To Make Friends and Influence People" reference in the thread title with a fart joke thrown in.

jbgibson
07-08-2011, 02:35 AM
I got it, I just let it... pass :-).

The doldrums would be wherever the Intertropical Convergence Zone is -- close to the "heat equator" that was mentioned as moseying north then south then north again. Don't think of it as totally no wind, think of it as faint wind from every direction to here, then the air rises. Or to put cause before effect, it's where the most heat of any latitude (on that day) makes air generally rise, and the rising air mass is replaced by inflow from both north and south. If I'm a sailor and any breeze is zero or toward me, I can't make progress anywhere.

Not sure of the reason for less indicated wind arrows over land.

Go a little further in the Megalaos sequence, and you'll see me place some general highs and lows. Those will generate directions like spiraling in and spiraling out. And yeah, there's no abrupt flip-flop from summer pattern to winter and back. Remember it's ALL generalizations and averages.... look at one good hurricane on the move, and you'll see the general pattern get overridden.

Mountains funnel wind, as through a gap, but otherwise don't divert it a lot sideways. Air masses would rather go up and over. That's a generalization - local winds and weather of course are affected by mountains a bit.

Porklet
07-08-2011, 02:44 AM
I got it, I just let it... pass :-).

The doldrums would be wherever the Intertropical Convergence Zone is -- close to the "heat equator" that was mentioned as moseying north then south then north again. Don't think of it as totally no wind, think of it as faint wind from every direction to here, then the air rises. Or to put cause before effect, it's where the most heat of any latitude (on that day) makes air generally rise, and the rising air mass is replaced by inflow from both north and south. If I'm a sailor and any breeze is zero or toward me, I can't make progress anywhere.

Not sure of the reason for less indicated wind arrows over land.

Go a little further in the Megalaos sequence, and you'll see me place some general highs and lows. Those will generate directions like spiraling in and spiraling out. And yeah, there's no abrupt flip-flop from summer pattern to winter and back. Remember it's ALL generalizations and averages.... look at one good hurricane on the move, and you'll see the general pattern get overridden.

Mountains funnel wind, as through a gap, but otherwise don't divert it a lot sideways. Air masses would rather go up and over. That's a generalization - local winds and weather of course are affected by mountains a bit.

That's a good one!

Doldrums...check. I'll look into your work. I have glanced at it, but I didn't want to get too far ahead of myself. Any notes on placing H/L pressure that's not in your descriptions? I'll make changes to the wind currents based on the new information about mountains after I have looked at your work. Thanks again.

Porklet
07-09-2011, 07:50 PM
Go a little further in the Megalaos sequence, and you'll see me place some general highs and lows. Those will generate directions like spiraling in and spiraling out. And yeah, there's no abrupt flip-flop from summer pattern to winter and back. Remember it's ALL generalizations and averages.... look at one good hurricane on the move, and you'll see the general pattern get overridden.

Mountains funnel wind, as through a gap, but otherwise don't divert it a lot sideways. Air masses would rather go up and over. That's a generalization - local winds and weather of course are affected by mountains a bit.

I have studied your progression with Megalaos, and I have included proposed H/L's for my world. My world map is much smaller. I didn't know if that would affect the number of H/L systems. I just followed what I thought was a pattern. I can lessen the number or combine them if you think that would be more plausible. The wind markers with the systems are to remind me which way the wind blows.

I do have two, or more, large High/Low areas next to each other. I didn't know if that would ever happen. Combine them? Make them smaller?

I have included both a Summer and Winter map. I have not started on the wind, because I wanted your feedback on my systems placement, please, sir.

Couple of quick questions:
1. With Calms, I thought I had it, but, do they move with the seasons? Are the always along the 23rd parallel?
2. On the Winter Map, is there another band of High Pressure at the 67th parallel?

You've been a great help to this point. Any help you can give would be appreciated.


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jbgibson
07-09-2011, 11:02 PM
Yeah, nearby highs or lows would probably coalesce. You do get troughs instead of point (single area, actually) sometimes. Picture only the largest seas and landmasses as 'anchors' for highs or lows.

I think in winter the 'polar high' just extends its circulation further toward the equator. The polar outflow is comparatively dry, which is why Antarctica is technically a desert. Plus, the colder the water the less evaporates and the colder the air, the less it picks up.

Yes, the doldrums do migrate north and south some seasonally.

Porklet
07-10-2011, 01:27 AM
Yeah, nearby highs or lows would probably coalesce. You do get troughs instead of point (single area, actually) sometimes. Picture only the largest seas and landmasses as 'anchors' for highs or lows.

I think in winter the 'polar high' just extends its circulation further toward the equator. The polar outflow is comparatively dry, which is why Antarctica is technically a desert. Plus, the colder the water the less evaporates and the colder the air, the less it picks up.

Yes, the doldrums do migrate north and south some seasonally.

Summer:

Lows: I combined the 2 major Lows into 1 centered on the large continent in the east. I purposefully left the southern side of the western continent along the Solar Equator without a Low. I didn't want it sucking in a lot of rain filled winds since I want to be dry. If you think it's not believable I can put an ancient range of mountains inland and in the wind's path.

Highs: I feel good about the north, but since the south is replete with bodies of water I combined all 3 of the major Highs into 2 and spread them out. Would a small High linger in between the two, would the 2 combine to form 1 larger High, or is it plausible as is?


Winter:

Lows: I am not certain the western continent can support a large Low. Should I make it a smaller sized Low? I want that continent to be dry as a bone (for the most part). From what I can tell that High to the south is going to throw rain at it. I could shift it east slightly and hide it behind the eastern mountain range.

Highs: I am not sure the western larger High (2nd from the left) could manifest over such a small section of land. Should I make it smaller? The small High in the center of the southern band: could that exist there, or would it combine with one of the two flanking larger Highs?


I don't know what happened to the last Winter map I uploaded. The bottom half was all greyed out. I have included the latest. If you could take a look at what I've done I would appreciate it. Summer is the upper one, obviously. Thanks JB.

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37002

jbgibson
07-10-2011, 11:33 PM
I'll label the summer ones W to E, Northern NH1 Nh2 Nh3 NH4, the lows l1 l2lL3 and l4, and the Southern highs SH1 SH2 Sh3. In winter I'll labe them l1 L2 l3 L4 l5 and h1 H2 h3 H4 h5. Uppercase vs lower case is whether they're a strong or weak system.

Another circulation effect we haven't mentioned is a general shoving of warm water and warming air westward by the easterlies just to the north and south of that intertropical convergence zone - the string of near-equator lows. Google "Walker cell". It's something that develops across our huge Pacific (http://www.windows2universe.org/earth/Atmosphere/walker_circulation.html), and probably would be even stronger above your three-quarters-of-a-world ocean. That generates a low around the east coast of a continent, and a high over trhe affected western coast. In your winter there wouldn't be much of this going on, since the ITCZ winds up totally south of your landmass.

Starting with your general High-Low placement here's what I think would happen.

Summer: l1 weakens or goes away and NH1 and SH1 shift together more. l2 and L3 drift north by five or ten degrees, with l2 swelling into L2. An ITCZ line bends north over land. l4 shifts eastward to become that coastal low of the Walker circulation, swelling into a bigger L4, but southeast of where you show it. A band or trough of low will extent most of the way around the backside of the globe, at maybe just 5 or 10 degrees N. That L4 low is the recipient of a huge amount of warm wet oceanic air all summer, and the coast where you show l4 is probably stormy and soggy. maybe June to November would be a hurricane season in your SE, from maybe 10 degrees N to 40 or so N. Nh2 and Nh3 probably coalesce into a single weak high, call it Nh23. I look at earthly maps and don't see discrete highs so closely spaced as your four northern ones.

A lot of your summer west-coast circulation is going to be N to S along the coast, with that big high pulling slightly cooler northern air down from your arctic. Cooler equals drier, so we can imagine that to be the equivalent of the airflow along the Andes. I assume it's the larger western continent you want dry? Hmmm - your 2/3 ring of mountains and that airflow probably could justify an interior desert. The very north and east edges, outside of the mountains, might be more damp. Air crossing that long inland sea couldn't help but pick up *some* moisture. Based on guesses before you draw in all the airflow, the inside of the tip of the hook of mountains in the southwestern continent/island could be pretty dry.

In winter your l1 L2 and l5 are probably about right. A winter 60-ish degree N string of lows appears to make more of a trough than beads on a string, if you will. I would guess the continental high would almost override l3 and L4 - say, erase both and shove an even bigger H4 up to about 30 degr N, due S of where you show L4. That's kind of what happens with earth's Asia in the winter.

For your winter map you may want to sketch in the slightly south-of-equator trough of lows. The clockwise outflow from northern hemisphere highs will be blowing kind of NE to SW when it gets to the equator Where there are pronounced lows - spots or blobs - it could torque to more NW to SE flow entering them. But you don't have southern landmases to bend the ITCZ much south though, so your winter is going to have close to the ideal ne to sw flow.that south-of-equator trough. Without significant southern landmasses, the airflow will stay more idealized. You'll have a conveyor belt of easterlies whooshing through those southern islands and all the way around the back of the globe, all winter.

What level of technology are your inhabitants? Once they develop long-range ocean travel, say clipper-ship sophistication, it'd be interesting to see how many traders risk a 3/4 circumnavigation to get from your west coast to east coast. That'd be an insane risk for galleys or galleons ;-).

Porklet
07-11-2011, 04:36 AM
I'll label the summer ones W to E, Northern NH1 Nh2 Nh3 NH4, the lows l1 l2lL3 and l4, and the Southern highs SH1 SH2 Sh3. In winter I'll labe them l1 L2 l3 L4 l5 and h1 H2 h3 H4 h5. Uppercase vs lower case is whether they're a strong or weak system.

Another circulation effect we haven't mentioned is a general shoving of warm water and warming air westward by the easterlies just to the north and south of that intertropical convergence zone - the string of near-equator lows. Google "Walker cell". It's something that develops across our huge Pacific (http://www.windows2universe.org/earth/Atmosphere/walker_circulation.html), and probably would be even stronger above your three-quarters-of-a-world ocean. That generates a low around the east coast of a continent, and a high over trhe affected western coast. In your winter there wouldn't be much of this going on, since the ITCZ winds up totally south of your landmass.

Starting with your general High-Low placement here's what I think would happen.

Summer: l1 weakens or goes away and NH1 and SH1 shift together more. l2 and L3 drift north by five or ten degrees, with l2 swelling into L2. An ITCZ line bends north over land. l4 shifts eastward to become that coastal low of the Walker circulation, swelling into a bigger L4, but southeast of where you show it. A band or trough of low will extent most of the way around the backside of the globe, at maybe just 5 or 10 degrees N. That L4 low is the recipient of a huge amount of warm wet oceanic air all summer, and the coast where you show l4 is probably stormy and soggy. maybe June to November would be a hurricane season in your SE, from maybe 10 degrees N to 40 or so N. Nh2 and Nh3 probably coalesce into a single weak high, call it Nh23. I look at earthly maps and don't see discrete highs so closely spaced as your four northern ones.

A lot of your summer west-coast circulation is going to be N to S along the coast, with that big high pulling slightly cooler northern air down from your arctic. Cooler equals drier, so we can imagine that to be the equivalent of the airflow along the Andes. I assume it's the larger western continent you want dry? Hmmm - your 2/3 ring of mountains and that airflow probably could justify an interior desert. The very north and east edges, outside of the mountains, might be more damp. Air crossing that long inland sea couldn't help but pick up *some* moisture. Based on guesses before you draw in all the airflow, the inside of the tip of the hook of mountains in the southwestern continent/island could be pretty dry.

In winter your l1 L2 and l5 are probably about right. A winter 60-ish degree N string of lows appears to make more of a trough than beads on a string, if you will. I would guess the continental high would almost override l3 and L4 - say, erase both and shove an even bigger H4 up to about 30 degr N, due S of where you show L4. That's kind of what happens with earth's Asia in the winter.

For your winter map you may want to sketch in the slightly south-of-equator trough of lows. The clockwise outflow from northern hemisphere highs will be blowing kind of NE to SW when it gets to the equator Where there are pronounced lows - spots or blobs - it could torque to more NW to SE flow entering them. But you don't have southern landmases to bend the ITCZ much south though, so your winter is going to have close to the ideal ne to sw flow.that south-of-equator trough. Without significant southern landmasses, the airflow will stay more idealized. You'll have a conveyor belt of easterlies whooshing through those southern islands and all the way around the back of the globe, all winter.

What level of technology are your inhabitants? Once they develop long-range ocean travel, say clipper-ship sophistication, it'd be interesting to see how many traders risk a 3/4 circumnavigation to get from your west coast to east coast. That'd be an insane risk for galleys or galleons ;-).

Thanks for taking the time to look over my maps.

It had occurred to me that I was placing a multitude of Highs and Lows based on what I observed on Megalaos. It being an entire planet, and my map covering 1/8 of a planet. It was a bit much. I am not entirely certain what is out there. I don't have a problem with there being no other land masses, unless that completely screws up the climatology. In answer to your question, they are in the late Iron Age. There technological levels vary between cultures, of course, but not by too much. That being said, they are pretty much "landlocked" to this continent and the surrounding islands so if there were other land masses it wouldn't affect the world too much.

The continent that I need to be dry is marked by L1 on the Summer Map. There are cities along the NE, NW, and S (between the ranges), but the interior needs to desert. With the all the Low pressures hanging out there that might prove difficult.

I have made the changes you advised below. I think I got them right.

Summer: I removed the ITCZ line from Summer since it was getting in the way of shifting the Lows around. I can imagine it for the time being. Does it follow the Lows? I removed the small Low in the eastern ocean, and shifted the two High's closer together. I am confused by the Highs shifting, but I trust your judgment. Would 2 Highs be so close together without a Low between them? I am okay with the east coast being bombarded by storms. It is sort of how I envisioned it except a little further south over the peninsula. I am guessing there will be a lot traders heading west over the winter months to do business in the southern seas.

Winter: Weather patterns are weird. I never would have guessed. I wasn't quite sure about the central smallish High hanging out in the southern ocean. You didn't mention it specifically, but I thought I'd bring it up anyway. Would it combine with the High to the west? I placed 3 Lows below the equator mostly to find out if that is the Latitude where they would fall and if there should be more of them. Also, since it's winter below the equator, and the Lows are over the water, should they be large Lows instead of smaller ones? Finally, I am assuming polar winds will be feeding into the north.

I'll draw in the troughs later, after I am sure of the pressure placement. Thanks again.

Summer

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Winter

37039

I have been studying your Megaloas wind maps, and I think I am getting the hang of it. But then again I could be deluding myself. Time will tell.

Porklet
09-18-2011, 02:18 AM
Response forthcoming...