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I also think that it should flow from west to east.
Wow, thanks Charerg! It makes the parts I had difficulty with seem so easily solved now!
@Azelor, Thanks for your explanations - I am slowly getting a better grasp of how they might work.
With Charerg's suggestions, I think I only have one final question/comment:
I think the north-east current at the top of the eastern continent around 45 degrees would be flowing to the west here because westerlies would still be dominant? I imagine it would be mild as it is fed by the warm current coming (a long way) from the equator, but I can also imagine it as cold because of the latitude and the polar current's influence?
I have tried to indicate currents I think would be mild in green.
Thanks once again! I will hopefully be able to figure out winds and start the climate maps soon.
Currents Suggestion2.png
I also think that it should flow from west to east.
When considering how far the westerlies reach, remember that they are also affected by the oceanic circulation (and therefore by the shape of the landmasses). For example, here's a map to demonstrate the point, based on the 1943 currents:
1943 Modified.png
For example, the Aleutian Low is located a bit lower in latitude than the Icelandic Low, and as a consequence the Westerlies tend to dominate the climate in Europe to a greater degree than in Canada. That said, I think the region north of your NE continent is one of those "toss of a coin" areas where either my prior version could be valid, or the westerly-driven current could reach farther east, like in your version.
However, if the current there does reach that far east, remember to take that into account when drawing the atmospheric circulations, since in that case a separate low pressure center would probably develop, as in this version:
Currents Suggestion3.png
The above is still a map of the ocean currents (not a wind map). Regarding your mild currents, generally I think you have them spot on, but you missed one in the SE corner of the map. I marked how I think the circulation would look like there on the map. I also did my take on "area 2". Here, I think the eastern portion of the sea there would be hot current influenced, maybe something like the Agulhas current south of Africa (at least this was the best "Earth analogue" I could find for this region).
Last edited by Charerg; 07-24-2017 at 04:23 AM.
Thanks Charerg, I can see why this current might be a toss-a-coin situation. On the one hand, there is no big landmass blocking the westerlies here, but it also means that the warm current would have to pass over the shallow continental shelf. With the influence of the westerlies and a low pressure system, I am more inclined to chose the westerly-influenced current.
(Edit: See latest wind map.)
Last edited by davoush; 07-25-2017 at 09:16 AM.
I discovered a wonderful resource to see how the world's winds are blowing (in real time).
https://earth.nullschool.net
Luckily for me, I was having most trouble with northern Hemisphere summer winds (aka July), so I spent a bit of time seeing how they work. Some observations have led to a few questions which I hope some of the more knowledgable wouldn't mind explaining?
I noticed that:
North Africa and the Arabian Peninsula seem to have small scale high pressure systems even in summer. Is this a year-round thing because of the latitudes? If so, I will probably have to decrease the big low-pressure zones I made for summer on my map as a large portion lies on the 'Arabian' latitudes.
Somalia seems to get a lot of on-shore wind, but is classified as mostly desert? Is there a reason why these winds don't bring precipitation after seemingly coming across a large stretch of ocean?
The India monsoon winds - I am unsure whether my map would feature such a phenomenon as this seems to be caused (or work with) the Asiatic low which decends so far? Am I right in understand that the north east trade winds are basically forced in the opposite direction around (or into) the low pressure?
Random tectonics question unrelated to anything: Most of the worlds (very big) mid-oceanic ridges are north-south (e.g. Atlantic), is this just coincidence? Can East-West ridges also occur?
Thanks all for your help, comments and willingness to share knowledge!
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Last edited by davoush; 07-25-2017 at 08:55 AM.
Originally Posted by davoush
If you look carefully, you'll note that the wind in Somalia actually blows offshore (except in the southernmost part of the country). Also, you generally need the ITCZ (or orographic lift) to generate rain in tropical latitudes. Which in Somalia's case means that there's effectively two "rainy seasons" (Spring and Autumn, when the ITCZ is over the area), but the wind pattern would be different during these seasons from the July pattern you see now, and most of the wind would probably come from the dry Arabian peninsula, limiting the amount of rain.
Regarding the Saharan high pressure centers, I'll admit I'm not too familiar with the details, but the region is bone dry in summer (Arabia does receive a surprising amount of rain in winter though, it's nowhere near as dry as the Sahara), so there may well be a semi-permanent high pressure system in place.
Regarding the Monsoon wind: any trade winds crossing the equator invert their direction (from easterly to westerly) because of the Coriolis force. This happens in SAmerica as well (take another look at that site during January and you'll see what I mean). Or for a more a more recent example, Africa:
Inverse Trade Winds.PNG
Note how the trades revert direction as they cross the equator.
@Tectonics:
As far as I know, the predominantly north-south orientation of the oceanic ridges is more-or-less random chance. Although one might say that it's probably not entirely coincidental in the sense that the plate movements in the Atlantic and the Pacific are part of the same system, and if South America, for example, moves on a west-east axis, the related spreading ridge would of course have to be orientated north-south (and probably this would impose north-south orientated stress on the subducted oceanic plate in the Pacific, making it more likely for a north-south orientated ridge to form).
That said, the spreading ridges in the Indian Ocean and the South Pacific are west-east orientated, so clearly they do occur (and have occurred numerous times in Earth's tectonic past, when plate movements have been different).
Last edited by Charerg; 07-25-2017 at 05:00 AM.
Thanks Charerg, I think I was putting the Indian monsoon in a special category because the change of wind direction here seems so much more intense/important to local climates. It is interesting that although Somalia's latitudes would have made me think it should be rainforest/savannah, the ITCZ movement actually influences its weather so much. It's these little details which I think can also make conworlds' weather more interesting!
I have updated my winds map of July - I think it is more accurate but I am still unsure of a few areas.
First and possibly most importantly - the ITCZ will move north slightly on both landmasses, but probably not as much as earth.
1) I think this sea would be high pressure as it has a cold current and so will be much colder than the surrounding land, giving it a high pressure. Would the westerlies override this high pressure area here?
2) I think these will be similar to the Sahara and Arabian peninsula - 20* ish latitude, dry. So perhaps a weak high pressure system? The Western coastal part - I am not sure if the winds should change direction a bit more strongly here? The trade winds coming to the ITCZ would be very dry, coming from desert.
3) I think the land here would probably be low pressure and fully humid. I am not sure if the surrounding sea would also be low?
4) This chain of islands: The north sides have a cold current and the south sides have a warm current. Which wind is most likely to affect them, and would they see a lot of precipitation? I think they are probably too small to see much of a north/south difference.
5) I was using China as an example where the low pressure extends into the ocean, but I am not sure that would happen here. The high pressure zone winds blow into the tall mountain range on the coast, and move up to the low pressure inland?
6) I think the westerlies would be dominant here, and wind would not be sucked onto the eastern side? Would it still be humid?
7) I think the areas highlighted are where rain might fall as the winds are mostly offshore.
---
January winds I have less questions:
1) This 'sea' - I did make it at first a low pressure zone in January, but would that mean it's current reverse in jan and July (is currently has a current coming from the pole and then flowing eastward - but high pressure should mean it flows the opposite direction?
2) I think these zones would receive onshore winds (and rain) in the Southern Hemisphere summer? That said, Australia receives similar winds and is desert in these latitudes?
3) I'm not sure if high pressure would occur here - maybe the westerlies would override it bringing rain? The grey line is a large mountain range so the east side at 30+ latitude might be in a rain shadow?
Also, I don't plan on making separate precipitation/temperature maps as I'm not using a script to define climates. I will instead do the climate zones manually, taking into account likely precipitation and temperature.
July winds:
July Winds Questions.png
Jan winds:
Jan Winds Questions.png
Last edited by davoush; 07-25-2017 at 12:14 PM.
There is definetly a high pressure system over the Sahara in winter and a low one in summer. But its not as low as it is in Asia. This might have to with the latitude and the smaller size of the landmass. The map you provided is instructive but makes it hard to see the dominant winds over long period. You can check these reference to have another view https://www.cartographersguild.com/s...l=1#post279343
The winds over Somalia blow mostly perpendicular to the coast so the moisture doesnt travel far inland, as a general trend. Also, these winds comes from dry region when the are overland. Also, Somalia is not completely a desert. Mogadishu receive more rain the Los Angeles but is drier because the climate is hotter. The coldest month is still hotter than the hottest month in L.A. and Mogadishu doesnt have any real winter unlike L.A. were temperature drop by 10 degrees Celsius in winter.
As chareng said, the monsoon is generally a wind reversal.
Here's my take on the July map
1 and 3 and 4: the seas at high latitudes in summer never have a high pressure. The pressure is always higher than overland though.
2. Again the pressure is higher than the surroundings but is still low compared to the overall map. Its gradual.
5 that depends on the height of the mountains. TAll ones block the moisture and affect the flow of air indeed but rarely stop it. I dont have a good understanding of the dynamic but i had a good link to an article about this somewhere. Its part of physics fluid dynamics.
6 Really strong winds and moist enough like Ushuaia, Argentina.
7 and more generally concerning the latitudes around 30ş S.
It is almost a continuous high pressure system over with most winds blowing west or east depending on the latitude. Some of yoursare blowing from the low to the high but it should be the opposite.
Lastly, you have several smaller isolated system , mostly low preseure, where winds converge but dont seems to interact with their surroundings. If you look at the maps.i linked earlier you can see that often, the air flow from one region to the other in a relativly smooth maner. From high to low from low to low and from low to lowest assuming we can find where the lowest is.
Thanks Azelor. I see why the maps in your link are actually more informative for seeing how the prevailing winds blow. I will update the wind maps accordingly and then hopefully into climates!
A quick question regarding the ITCZ: On the continent which is in the West in the most recent maps, there is a kind of subcontinent - The tip is near the equator in that area of shallow sea. In July the ITCZ reaches about 15* and then descends towards the sea. As it is now, it probably means anything over 15* is going to become seppe/desert. But if I move the ITCZ north a bit, the southern half of the subcontinent would probably resemble India?
I know this may be a 'toss a coin' thing but I'd like to hear thoughts/opinions before I finalize the ITCZ here. On the one hand, there is a lot of land around the 0-30 latitudes, but the landmass itself doesn't extend as far north as Asia (and overall isn't as big), and there is a lot of shallow sea around the equator in this part.
Last edited by davoush; 07-26-2017 at 08:26 AM.
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