How plausible is an alive atmosphere?

Question

We know there are microorganisms living some good kms above our heads --- bacteria, fungi, even algae were detected in meteorological samples. What if the unstable mixing of gases that happens in the troposphere and some occasional thunderstorms have cooked up those microbes so they evolved into multicellular organism and then eventually to more complex lifeforms.

I was thinking of some kind of colonial organism like Portuguese man o' war, sea sponges and corals. Tiny polyps connected together to form airborne structures.

Let's call it Atmoid.

Atmoid's biochemistry could adapt to convert atmospheric gases and sunlight into energy and store water in the form of vapor, maybe using solar beams to create a greenhouse effect within its translucent body heating up its inner gases so they become less dense, which means Atmoid is basically a living balloon.

With basically an infinite source of energy, Atmoid can grow to colossal sizes, absorbing most of the sunlight that passes through it and casting a ominous shadow on the equilibrium of the biomes bellow.

Since some tropospheric microbes can work as aerosols and catalyze bio-precipitations (it means bacteria can make it rain), maybe Atmoid can have some weather manipulation abilities.

Catalyzing clouds to create rain and blizzards decreases the temperature in lower regions, which increases the density difference that Atmoid needs to stay afloat, so Atmoid can grow even more without bothering with weight.

Atmoid grows as the sunless world bellow freezes and enters a new ice age.

Atmoid's size eventually circumvents Earth and covers all the sky. No, IT IS THE SKY!

Atmoid now absorbs all the energy that comes from the sun, its single planetary colony now reached level 1 civilization without even known how to make fire!

Claps for Atmoid!

What's the plausibility of such a organism without much handwaving?

Answer 1

It needs to be a windless world.

source

I like the idea. Bodies of water can have photosynthesizers carpet the entire upper surface, shading out whatever is beneath. This is contingent on adequate nutrients in the water and lack of wind to sweep these unmoored organisms away.

Trees can become confluent and shade out the ground. They are well anchored, and by virtue of anchoring roots have access to nutrients in the soil.

Your confluent Atmoid touches the ground and so has access to nutrients at least in the top layer that it can absorb and redistribute thru its mass. Wind would be tough on the atmoid and could tear it or throw it - just as in water wind and waves sweep away buoyant vegetation and buoyant life forms like cnidarians. The atmoid would need to be internally reinforced with some macroscopic equivalent of cytoskeletal elements to retain integrity. If this world had no or minimal wind the atmoid could do well.

Interlopers will want to get inside the atmoid and pillage its resources. I envision motile defensive units that would converge on intruders - analogous of our own immune cells defending our bodies against invaders. I like the idea of a variety of these deployed as appropriate. Some might have accumulated toxins found on the ground or synthesized in special organs, and then release these onto the intruders.