Yläilmoista

Yläilmoista refers to the upper atmosphere, a region of Earth's atmosphere above the troposphere. This vast layer encompasses the stratosphere, mesosphere, thermosphere, and exosphere. The stratosphere, extending from roughly 10 to 50 kilometers above the surface, is known for its ozone layer, which absorbs most of the Sun's harmful ultraviolet radiation. Temperatures in the stratosphere generally increase with altitude due to this absorption.

Above the stratosphere lies the mesosphere, reaching up to about 85 kilometers. This is the coldest part of the atmosphere, where meteors typically burn up upon entering Earth's atmosphere. The thermosphere, above the mesosphere, extends for hundreds of kilometers. Here, temperatures can become extremely high due to absorption of solar radiation, though the air is so thin that it would not feel hot to humans. The International Space Station and many satellites orbit within the thermosphere.

The uppermost layer is the exosphere, where the atmosphere gradually thins out into outer space. The precise boundary is not well-defined, but it is generally considered to begin around 500 to 1,000 kilometers above Earth. Phenomena such as auroras occur in the thermosphere and exosphere, caused by charged particles from the Sun interacting with Earth's magnetic field. Studying yläilmoista is crucial for understanding weather patterns, climate change, and space weather.