Sunday, September 11, 2011

Áereth: Geophisical Data

The Axial tilt puts the arctic lines at North & South 62.5o of latitude.

The Northern Tropic line at N27.5o is known as the “the Tropic of Choranus” & its Southern counterpart at S27.5o is called the “the Tropic of Centivus.”  The equator is referred to as “the Girdle of Ildavir.”

The Permanent Ice Line can be found at North & South 86.5o latitude and below or above this line (with respect to hemisphere) is the zone that experiences 1 day per year: 5 months each of night and day centered on the respective Solstice, with 6 weeks (1.5 months) of sunrise or sunset.  The snow and ice are permanent at this latitude due to the twin facts that the sunlight travels through so much atmosphere that there is very little energy left in it when it reaches the surface of Áereth; and, that there are prodigious deposits of “blue-ice” [see Frostburn Setting Guide].  The North Pole experiences milder temperatures due to the planets orbit being closer to the Sun during northern winter.  This has created a much more populated arctic zone than at the South Pole with Green, Red, Blue, and even Yellow types of algae that have evolved to live in these regions.  They live in colonies suspended within, but near the surface of the ice and snow of the glaciers, the extra albedo causes enough melt in the summer season that they can get the liquid water and mineral nutrients they need.  These patches of algae are the only source of vegetative protein at these latitudes so it is consumed in small quantities even by carnivores out looking for some of the vitamins & minerals they need.  And yes, I do realize that this means that you can eat the yellow snow; but adventurers beware!

The last of the deciduous trees are found growing at approximately 57.5o north and south latitude, but with the high magic field and the general flexibility of the D&D environments, exceptions to this rule do occur, but are rare.

In general, and in comparison with Earth: the axial tilt of the World of Áereth makes for larger tropical zones and a larger northern and southern temperate band that flows quickly into a narrow sub-Arctic and smaller Arctic region.  The greater then normal axial tilt means that the heat on the planet is exchanged more effectively than it is here on Earth, but it has narrower windows to do so.  This means that the change of seasons in the northern hemisphere of Áereth isn’t so much of a slow stately process, but more like an oncoming herd of stampeding rhino.  This is due to the driving forces of the southern hemisphere getting so much hotter than the north during southern summer, and the fact that the southern hemisphere is mostly ocean.  Additionally, the Southern Ice cap has a small permanent center just as its northern counterpart, but in the southern winter the planet is far enough away from the Sun that a very large and thick ice sheet builds up and stretches all the way down to 700 in a short amount of time.  It melts just as quickly in the fiercely hot southern summer.  This combination supercharges the atmosphere with warm water vapor... and all that heat and water have to go somewhere...  The water gets dumped mostly on the “Southern Continents” because the Empyrian Ocean is so small compared to the rest of Áereth’s oceans; and the heat drives horrific storms in the north and south as the temperatures seek to balance themselves.  These forces create a dynamic such that all Wind Categories listed in the D&D and Áereth rule-books are increased in potential.

No comments:

Post a Comment