What would be the effect of a giant magic fireball burning in the ocean?
(I got a lot of good information in the responses. I'm doing some research and will edit my post to be more specific.)
Imagine there's a magical fireball that stays in one spot in the middle of the ocean and emits heat at a constant rate that is hot enough to evaporate any water on contact. It's visually sun-like but doesn't do all that fusion crap, it just sits there perpetually emitting its fiery hotness.
Let's say it'll be big enough that its diameter will go all the way to the ocean floor while also sticking out of the surface of the ocean at the same time (ocean avg 3.5km deep), but smaller than the size of a dwarf planet/asteroid like Ceres (approx 939km diameter). So let's call that a range of 4km to 900km in diameter for our fireball. It ought to be somewhere in that range; I'm still playing with the size.
My fantasy planet is Earth-like in size and in ecosystems (with some fantastical exaggerations and distortions lying around). I'd imagine:
- Fatal amounts of heat and steam within X distance of the fireball
- Loads of precipitation wherever it cools back down
- All that rain causes flora and fauna to flourish in those areas
I believe there may be other considerations that I'm overlooking to really understand what might go on here. With the given size and enormous volume of water, would this be big enough to affect the whole planet? As in all of the major wind and water currents? Would it sauna everyone to death? What would the water flow be like immediately around the fireball? How different will the effect be at different fireball sizes? Are there any other considerations for this setup that you can think of? Do you know any real-world experiments or setups to look at that may shed light on this issue? I tried to find some "large amounts of water vs very hot object" videos but didn't quite find what I was looking for.
I'd like to have a more functional understanding of the effects at play here because I'm certain the inhabitants of the area would as well. Like I could see the effects of this fireball shaping agriculture, sailing, flying, and even religion/culture for the people living in the region. What do you think?
I don't have a map of my fantasy planet, so picking a real-world ocean and plopping this fireball thing in the middle of it may be a good focal point to figure out the details. Let's say in the Pacific. Thoughts?
Thank you for your time.