View Full Version : WIP Atheben

09-07-2008, 04:53 AM
Hello, i have been a member on this site for quite some time, but haven't dared to post anything or introduce myself. I'm in need of help with my worldmap that i'm currently working on (sorry for my bad english).

I have drawn maps for some time now but everytime I decide to make a "prefect" map i do something horribly wrong with it. This time I want to do everything right. I looked around on the forum and someone said that the "climate cookbook" is a good site to start with. But unfortunatly i don't really understand the first topic on the site, "the pressure cooking". So if someone wants to take his or her time to explain it for me, I would be very greateful :)

Here is my map that I want some help with. This is just a test map if you could show how the pressure belt would look like.

09-07-2008, 06:40 AM
Hello Uomaru, and welcome to the guild :)

I have personally found this diagram to be rather helpful in understanding how pressure belts work (on an Earth-like planet, anyway):

http://img205.imageshack.us/img205/8598/pwpptgczf7.gif (http://imageshack.us)
http://img205.imageshack.us/img205/8598/pwpptgczf7.53b141d0ba.jpg (http://g.imageshack.us/g.php?h=205&i=pwpptgczf7.gif)

Essentially, wind flows from high pressure areas toward low pressure areas. The diagram shows how prevailing winds would always flow IF the planet doesn't have axial inclination and no big landmasses.

When the planet's axis is tilted, there will be seasons which make both land and water heat up during summer and cool down during winter. But land gets colder during winter and hotter during summer than water does, so there will be difference in temperature between the seas and continents.

What happens because of this is that at summertime, high pressure areas form over landmasses and low pressure areas form over seas. At wintertime it's the opposite. Hence, winds tend to blow from land to sea during summer, and from sea to land during winter. But actual wind direction will depend both on the prevailing wind pattern (shown in the diagram) and also of the land vs sea effect of summer/winter. Typically the high & low pressure areas forming over seas and continents will only cause slight changes to wind direction from those shown in the diagram, but IF a landmass is very large it can completely reverse the direction (which creates the monsoon).

One very important thing is to understand that the seasons are different in southern and northern hemispheres. When there is summer north of the equator, there is winter south of the equator, and vice-versa. For this reason it's best to focus on each hemisphere one at a time.

Now in the map you posted, assuming it's Earth-like in size and axial inclination, I would say that the large continent on the western hemisphere would create a monsoon but the others would not. The big plain on the northern portion of this continent, between the mountains, would "normally" be largely desert due to being located at the Subtropical High (latitude circa 30 degrees) and blocked from prevailing winds by the mountains to it's east and west, but the summer monsoon might be able to suck enough air from over the northern sea to make the region less arid.

Hopefully you found this helpful.

09-07-2008, 10:36 AM
Thank you very much for your reply. I greatly appreciate your help :) It will be alot more easier now!