I think the correct answer is crust. I am really sorry if I am wrong.
Answer:
Tropical cyclones are like giant engines that use warm, moist air as fuel. That is why they form only over warm ocean waters near the equator. The warm, moist air over the ocean rises upward from near the surface. Because this air moves up and away from the surface, there is less air left near the surface.
Explanation:
Low pressure!
It tends to go from high to low in air pressure! (: If you didn't know - atmospheric pressure can be determined by something called a mercurial barometer! I hope all is well, and you pass! Good luck, rockstar! (:
Let me know if you have any questions, or any comments! (:
Geologists have used two main types of evidence to learn about Earth's interior: direct evidence from rock samples and indirect evidence from seismic waves.