In which layer of the atmosphere does all weather (rain, snow, clouds, storms) occur?
AStratosphere
BMesosphere
CTroposphere
DThermosphere
The troposphere is the lowest layer (0-12 km) and contains about 75% of the atmosphere's mass and almost all of its water vapor. All clouds, rain, snow, wind, and storms occur here. This is the layer we live in and interact with every day.
Question 2 Short Answer
Why does the stratosphere get warmer with increasing altitude, unlike the troposphere which gets colder?
Think about your answer, then reveal below.
Model answer: The stratosphere contains the ozone layer. Ozone molecules absorb ultraviolet (UV) radiation from the Sun, converting it to heat. The more UV that is absorbed, the warmer the air becomes. Since UV comes from above, the upper stratosphere absorbs the most and is the warmest.
This temperature inversion (warming with altitude) is why the stratosphere is very stable — warm air sitting above cool air does not rise. This stability is also why commercial airplanes fly in the lower stratosphere: it is above the weather and the air is calm.
Question 3 True / False
The atmosphere has a clear, sharp boundary where it ends and outer space begins.
TTrue
FFalse
Answer: False
The atmosphere does not have a sharp edge. It gradually thins out with altitude — there are fewer and fewer air molecules per unit of volume. The Karman line (100 km altitude) is often used as a conventional boundary for space, but it is a human-defined line, not a physical boundary. Some atmospheric molecules extend thousands of kilometers above Earth's surface.