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There is a background planet in this story that is important due to character back story however we never visit it in this book.

It is describe as a mostly jungle planet, with regular heavy rains or monsoons but little to no bodies oceans or large bodies of water.

How feasible is this? What other conditions would need to be added to allow the monsoons without much water surface water?

The planet would have to have been stable long enough for life to have evolved there.

EDIT

The answeres provided gave me the info I needed to do further research. An acer of water evaproates about 10,000 gallons a day. An acer of corn can lose 8,000 gallons a day through evapotranspiration.

Through this I can imagine a world with minimum to no handwavium with these characteristics. So the correct answer goes to @SJuan76. Thanks go out to @JBH and their excellent answer as it gave me the terms I needed to further my search.

http://www.ncga.com/upload/files/documents/pdf/water_movement_in_corn_production.pdf https://www.tractorbynet.com/forums/rural-living/81477-how-much-water-evaporates-per.html

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    $\begingroup$ Off the top of my head, certainly feasible. There would be very little tectonic activity, to have very shallow seas, possibly most of the water in a planetary aquifer that's in range of the roots. Humidity and clouds to create the torrential downpours would be created by the plants themselves, releasing water vapor as a normal part of photosynthesis, just as rainforests on Earth do. $\endgroup$ – Ghedipunk Jun 29 '18 at 22:15
  • $\begingroup$ Maybe if your world's soil acts like a giant sponge: layers and layers of moss retaining water in the ground, so there are no oceans but the larger areas of bodies are no bigger than lakes or ponds? $\endgroup$ – kikirex Jul 2 '18 at 14:38
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Sand, lots of it

Sand is permeable, which means that rain water falling on it will sink down (at least, until the lower layers are soaked).

So you have a planet with lots of sand, let's say some 20 meters minimum all around1. When it rains, water sinks down until it finds an impermeable layer, and it remainst trapped there.

And now you have to get the water out...

Trees, lots of them

But those trees have to dig hard to get the water. They roots go deep in the sand1 until it reachs the water (the phreatic level). Roots will suck water and send it towards the leaves; where it will evaporate (respiration and photosyntesis) and return to the atmosphere.

Considerations:

  • A new tree will need a lot of water to build its initial root; if they use seeds those are going to be huge and full of water. Or maybe they do not use seeds and new trees appear as an outgrown of other trees roots, or the trees can "drink" from the roots of older trees while growing their roots.

  • There may be a need for a mechanism to "process" dead tree remains. Otherwise, they will decompose and will form, little by little, fertile soil. Maybe the soil is pushed down by the rain?

  • No tectonic activity will help, as no new rocks will be pushed to the surface and no new soil will be created.


1Which also gives them structural support, because, you know, they are literally built on sand.

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This is not feasible

Atmospheric water must come from somewhere, and it cannot come from underground springs. The one and only option to do it in bulk is evaporation.

You don't describe your planet in detail, but let's assume that it's close enough to the sun to keep the poles melted. They won't be tropical (or the rest of the planet would be a blazing desert), let's assume they're arid.

That makes the rest of the planet fairly hot. Good. We need rapid evaporation. We have tons of trees and low tectonic activity so the water has worn most of the land fairly flat. (That's a problem by itself, BTW, because erosion is no small thing, but let's ignore that.)

You do get a ton of water into the atmosphere via transpiration (the plant form of sweating), but not nearly enough to create monsoons. For that you need open water to evaporate.

Could you do it with a swamp planet? Well... maybe, but if you're looking for no surface water, soggy swamp may not solve the problem. If soggy swamp could solve the problem, then you're looking at basically 100% humidity planet-wide. Yuck. Good for plants. Hard for critters (like humans) that need to breathe. (But, then again, sapient bipedal fish aren't unheard of.)

In reality, though, a planet with monsoons will have oceans, if only because an entirely flat planet (the only way you don't get oceans) is pretty unrealistic. Give a little altitude anywhere, even a few feet, and the water from those monsoons begins to puddle and gather. And you need them to evaporate enough water to create those tropical monsoons.

Think of Earth. 67% surface water, and we're NOT a tropical planet with regular monsoons. And yet you're looking to do it with 0% surface water. That's why I'm voting for not feasible.

But that's not the same as "don't use it in your story"

Having said that, IGNORE ME COMPLETELY. Oftimes authors get too bogged down in the details. The number of people who read your story and think to themselves, "that jungle planet with lots of rain and no oceans is sooo unrealistic!" compared to the number of people who think "This is the most awesome book in the world!" is so honking low that it's statistically zero. Up theirs (if you'll excuse my french). Have fun with your story and forget everything I said.

Cheers.

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Oh, it's quite feasible.

But it would be an inferno: a Venus-like planet, minus the chemical craze, where it is so hot that ALL of the world's water has evaporated and stays in the atmosphere. And when it rains, it evaporates before touching the surface, thus keeping the cycle at a higher level over the surface -which would be totally dry and subjected to an enormous pressure.

If plants had a chance to survive, they'd need to live on mountains, be very tall and have the thickest bark to retain water and survive the surface temperature. Like baobabs, their roots would be propelled upside to collect all humidity from the suspended atmosphere water

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