Seriously,
Planetary Energy Budget should be in the BUILDING BLOCKS-section but, I
guess is too far away from basic stuff, although is something you
should care about anyways.
Imagine
an aquarium, the fish inside can only grow as large as the amount of
food you give them, or a garden, where plants will only grow as large as
the minerals available in the soil.
Getting
it? Now try picture all of the energy coming from the Sun, and how it
flows across the atmosphere, the sea, the soil and biomass, the chain
that starts with chemicals born in the atmosphere, absorbed by plants,
absorbed by plant eaters and then by YOU... What may seem practically
infinite, is an enormous but FINITE amount of energy, given to us
through sunlight...
Our ENERGY BUDGET, is basically the measurement of how much is are allowed to happen in a certain place given the available amount of energy.
The
same way a plant won't grow well (will certainly die) only with indoor
lights, plant-life won't grow well around star that is not as luminous
as the Sun, or the same way bacteria on your gut won't evolve beyond
their current state because their energy budget is limited to our body
heat and food, life on a world too far away from it's star (like the
moon Titan) will have it's energy budget limited to it's internal heat
and chemosynthesis.
To prevent THIS from happening to your planet, in other words...
OK.
Earth's ENBUT ("ENergy BUdget" + "inpUT") happens to be 100 units, or 1.360 W/m² facing the Sun.
How those 100u are spread across Earth
Luckily, we always measure everything relative to Earthly values...
If our star has L = 0,5, it outputs half the energy / light as our Sun.
Thus,
the amount of light that reaches a planet 1AU away is basically half as
Earth's, ie, probably it's capacity is around 1/2 as Earth's.
I
said probably because we need to take into account how large it's
illuminated side is, what can be made with quite an ease, having the
maps and previous calculations ready.
For
the overall reflectivity/absorbency of the energy by your planet, I
suggest you to pic your map/texture (clouds included), greyscale it in
such a way your ice-caps' (if you have some) RGB goes up to 255-255-255,
then blur all of your image, blur it until it look like a "single
homogeneous" shade of grey, divided its repeating code by 255.
If for instance it's final average tone is 170-170-170, follow as 170/255 = 0,66, then your planet is able to absorb around 66% the light it receives, then it also reflects about 34% the light it receives.
The more Earthly your planet appear to be, the more closely it will distribute its energy like Earth does:
1/3 reflected back to space.
1/6 absorbed by the high atmosphere.
1/3 used by the water cycle.
1/6 directly absorbed and radiated to space by ground.
Now
that you have got this proportions, we have to find if at least your
planet can maintain a reasonable water cycle, since the movement of
water in our atmosphere is the big climate player. Since we know that an
Earthly atmosphere could still hold enough heat to maintain liquid
water.
Take 1 ENBUT Unit as 13,6 W/m2.
Still, with that half luminosity planet as example, at 680 W/m², our ENBUT is about 50 units.
If
1/3 of that is used for the water cycle, we have about 16 units for
that, which is half as the used on Earth, if that planet holds as much
water as Earth then most of it is very cold or frozen, unless the planet
has little water available so that is enough to run it well.
Compare
this to warming a liter of water over a stove, the stove is energy by
the Sun and the water is water available on Earth. Now if our planet has
a liter of water but is heated by a smaller stove burner, then it won`t
boil at all or not so fast at least, but if we have less water on the
pan using the same small stove burner, then we can boil it faster if not
at the same rate.
It
is a very interesting thing to think about, imagine aliens that come to
Earth but have to eat a lot more than usual because our food is less
nutritious coming from a dimmer star than theirs. Or the reverse, we
having to farm on Venus due the greater ENBUT available there.
Keep in mind that Oxygen reactions gave life more energy
to grow and evolve, past 3Byrs without breathing Oxygen they were stuck
in single-celled life, then when it happened, BOOM, in 600 million
years life got multiple cells, thrived in dry land and went to the Moon.
<.< this is why Superman is kinda weird since our yellow sun is actually dimmer than Krypton`s Red Giant, if his powers depend on the star light, then he would be stronger under a Red Giant...
Expect
worlds with a large energy budget to have extreme weather/life, in the
sense of great rainstorms, brighter auroras and stuff, or life to be
flourishing at amazonian levels everywhere, while planets around dimmer
stars are stuck into rather simple and small beings.
In Paart's case, being 1,11AU away from Vol, it's average lighting is about 65% Earth's, so Paart have about 65u to spare, I define, ~16u which is bounced back into space 'cause of clouds, ~18u used for the water cycle, ~21u absorbed the dark ground and ~10u absorbed by the thin atmosphere.*outdated*
Here we have it, as far, Paart uses half of the energy Earth uses for it's oceans, being of similar size and having as much water, it is expected to have more calm oceans, with at least with half the waves strength and stuff, which I'm going to let like it is, because still water is more likely to absorb carbon dioxide from the atmosphere, hence CO² breathers we mentioned before.
As well, it is absorbing 1,26x more energy on ground, since it is darker and have a larger surface area than Earth, opens an interesting possibility, because the amount of plant-life and artificial buildings can directly alter the planet's albedo and thus it's climate.
- M.O. Valent, 23/05/2019
