e moves from the equator toward the poles.
Planets with a moderate degree of axial inclination will experience pronounced seasons as the year progresses. During the summer, that hemisphere tilted toward its sun will experience seasonably higher temperatures. A half of their year later, when the previously warmer hemisphere is tilted away from its sun, it will experience seasonably low temperatures. These seasonal temperatures create an overall average temperature for each latitude and region.
On a planet with no axial inclination, each latitude would still have a narrow annual average temperature between it’s ‘summer highs and winter lows’, this derives from the probability that the planet’s orbit is not a perfect circle about the parent star, a condition similar to Earths orbit. The extremes for all latitudes, on either side of the average, would be eliminated by the lack of axial inclination.
On Earth, the average annual temperature for a given latitude is that temperature the latitude would have if Earth had a 0º, instead of 23-1/2º axial inclination.
Shown in the Biotic Zone Table below, are the annual average planetary surface temperatures for each latitude. Since we have eliminated the temperature variation by using ‘average temperatures’, we can in effect say that if these temperatures were maintained throughout the year, that the planet has no axial inclination.
Lets now say that on any planet where there is no axial inclination, the temperatures vary with latitude just as they would on a Earth with no axial inclination. If this is so, we can compare temperatures with latitude for planets displaying all the APST used in this study. We should remember that the resultant temperature models provide:
• The annual average temperature for each latitude on a planet with 0º axial inclination, or,
• the annual average temperature for each latitude as derived from the overall seasonal variations on those planets with axial inclination.
In the Biotic Zone Table, compare temperatures (in degrees Fahrenheit and Centigrade) with latitude for each of our planetary models.
Earth equivalent biotic zones have been colored into the chart showing the migration of plant life related to APST.
The temperatures given in the table were calculated as follows:
Example #1: 140ºF (hot planet’s APST) – 68ºF (Earth’s APST) = 72ºF difference (on hotter planet)
Therefore, 72ºF hotter (in general) + 81ºF at Earth 0º latitude (equator) = 153º F at 0º latitude (equator) on hot ASPT planet.
Example #2: 68ºF (Earth’s APST) – 32ºF (cold planet’s APST) = -36ºF cooler difference (on cooler planet).
Therefore, -36ºF cooler (in general) + (-4ºF on Earth at 70º latitude) = -40ºF at 70º latitude on the cold planet.
Look across the top of the Biotic Zone Table to locate 113ºF, then read down the column to find the approximate surface temperature at a given latitude. On a planet with an APST of 113ºF, the equatorial temperature would be about 126ºF, at 60º latitude it would be a warm 80ºF and a cool 41ºF at 70º latitude.
Drawn to overlay the preceding table are the color coded, approximate temperature and latitude boundaries, of the various biotic communities found on Earth. I’ve extended the APST range an additional 15ºC on either side of the conditions used in this study to demonstrate the serious deterioration of the planets habitability, see double blue and double red verticle lines toward either side of the chart.
In the column at far right, Earth’s APST (average planetary syrface temperature) and general biotic conditions per latitude have been included for comparison.
Note that the biotic community we are accustomed to on Earth, would be seen to shift toward the planets equator with a reduction in the average planetray surfave temperature; conversely, the biotic zones would shift toward the poles with an increase in APST.
In order to better understand the migration of biotic zones and the general climate of our model planets, I’ve included the illustrations below showing and equatorial and polar view for each 15ºC change in APST within the SRAPO filter