I have an idea for a planet, this planet has continents and oceans like Earth does, the main difference is that the continental shelf is about 3 miles above sea level, whereas on Earth the continental shelves are below sea level. The oceans are a few hundred feet deep and have flat bottoms and still manage to cover 70% of the planet's surface and at Sea Level the Atmosphere is considered Dense according to the Traveller definition. The temperature at the ocean surface is about 150 degrees F at the equator, but as you climb the cliffs of the continental shelf, the temperature drops to around 80 degrees F at the equator. The planet is size 8 and the weather patterns and axial tilt are similar to Earth's.
How high up does a Dense Atmosphere become Standard?
- Thread starter TKalbfus
- Start date
TheEngineer
SOC-14 1K
Hi,
just a quick formula:
p(h) = p0 * exp((-g*dens0*h)/p0)
p0 and dens0 :
pressure and density at sea level
But, thats only for constant temp...
just a quick formula:
p(h) = p0 * exp((-g*dens0*h)/p0)
p0 and dens0 :
pressure and density at sea level
But, thats only for constant temp...
M
Malenfant
Guest
More accurately, the scale height formula is:
P=Po exp(-gh/H)
where:
P is the pressure at height h
Po is the pressure at the surface (atms)
g is the surface gravity (m/s2)
h is the altitude above 'surface level' (m)
H is the scale height (the height at which pressure drops by a factor of 1/e (=37%). Two scale heights up means that the pressure is 0.37X0.37 times the surface pressure, or 13.5%.
H is given by:
H = RT/mg
where:
R = 8314.3 (universal gas constant)
T = Temperature (assume it's about the same as the blackbody temperature of the planet?)
m = molecular weight of the atmospheric gas
g = surface gravity in m/s2
P=Po exp(-gh/H)
where:
P is the pressure at height h
Po is the pressure at the surface (atms)
g is the surface gravity (m/s2)
h is the altitude above 'surface level' (m)
H is the scale height (the height at which pressure drops by a factor of 1/e (=37%). Two scale heights up means that the pressure is 0.37X0.37 times the surface pressure, or 13.5%.
H is given by:
H = RT/mg
where:
R = 8314.3 (universal gas constant)
T = Temperature (assume it's about the same as the blackbody temperature of the planet?)
m = molecular weight of the atmospheric gas
g = surface gravity in m/s2
Thanks, I was thinking of working on the Planet Prometheus, it has 50% hydrographics and a Dense Atmosphere, at sea level that is. My idea is to have a low sea level with shallow oceans at the bottom of mostly empty ocean basins. If the ocean basins were filled to capacity, hydrographics would be more like 75%, but since their not their at to major features besides oceans. Bottom lands and table lands. The bottom lands are the low lands around the oceans, it is here where the atmophere is dense and hot. At the platue of the table lands the atmospheric pressure drops to 1 bar and about 25% of the planet's surface is at this altitude or greater. The Prometheus of My Traveller Universe is inhabited by humans originally transplanted by the Ancients, but unlike the Vilani, they did not advance as far technologically. There is another creature that plays an important role here. This is the Prometheian Dragon, this dragon has 12 age categories just like a D&D Dragon, has grey scales, wings and breaths fire, or more accurately has a built in flame thrower in his gullet that projects and ignites an oil that is produced within the Dragon's body. The Dragon is intelligent and is capable of speaking human languages, it is basically a generic dragon, but without the shape changing ability or the magic.
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