If you ride a bus or drive from Mexico City (2,240 m) toward Popocatépetl or Pico de Orizaba, you notice that it gets colder and that you feel a little short of air. You are passing through a layer of gases that surrounds the whole planet: the atmosphere. Without it, Earth would be a scorching desert by day and freezing cold at night.
Air and Its Composition
You feel the wind on your face, you see a sail fill up, and you notice the resistance when you push the plunger of a syringe with its tip blocked. What is this invisible mixture we call air made of?
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Air is made up of approximately 78% nitrogen, 21% oxygen, and 1% other gases (argon, carbon dioxide, water vapour, etc.). Order these components from highest to lowest…
Air is made up of approximately 78% nitrogen, 21% oxygen, and 1% other gases (argon, carbon dioxide, water vapour, etc.). Order these components from highest to lowest proportion and represent the data using a simple bar chart.
You can do it on paper and send a photo with your answer.
The diagram shows the layers of the atmosphere (not drawn to scale). a) Which layer is labelled with "?"? b) In which layer do clouds form and storms occur? c) Which gas…
The diagram shows the layers of the atmosphere (not drawn to scale).
a) Which layer is labelled with "?"?
b) In which layer do clouds form and storms occur?
c) Which gas forms an area in the layer labelled with "?" that absorbs ultraviolet radiation from the Sun?
A rocky exoplanet similar to Earth has been discovered that receives comparable stellar radiation, but whose atmospheric analysis indicates that it lacks an ozone layer…
A rocky exoplanet similar to Earth has been discovered that receives comparable stellar radiation, but whose atmospheric analysis indicates that it lacks an ozone layer in its middle region and does not retain water vapour in its lower layers. Reasonably justify which protective and regulating functions fulfilled by Earth's troposphere and stratosphere would be absent on that planet, and predict two critical consequences for the viability of life on its surface.
Higher up the pattern changes again. In the mesosphere the temperature drops again with altitude, down to about $-90$ °C near 80 km: there is no ozone left to heat the air. In the thermosphere it rises sharply again, because the little gas there is absorbs the Sun's most energetic radiation. So the temperature falls (troposphere), rises (stratosphere), falls (mesosphere), and rises (thermosphere). Each change in trend marks the boundary between two layers.
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As you climb a mountain, the temperature drops, even though you are closer to the Sun. Explain which layer of the atmosphere this temperature drop corresponds to and…
As you climb a mountain, the temperature drops, even though you are closer to the Sun. Explain which layer of the atmosphere this temperature drop corresponds to and reason why the peak of a high mountain is cold.
A weather balloon records the following temperatures as it rises: 15 °C at the surface, −50 °C at an altitude of 10 km, 0 °C at 45 km, and −80 °C at 70 km. State which…
A weather balloon records the following temperatures as it rises: 15 °C at the surface, −50 °C at an altitude of 10 km, 0 °C at 45 km, and −80 °C at 70 km. State which layers of the atmosphere it passes through in each section and explain the change in trend observed in the data.
When you stick a suction cup on a window or drink a soda through a straw, a mysterious pull seems to be at work. What force pushes so firmly on every object on Earth's surface?
Why the Atmosphere Is Essential
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State two functions of the atmosphere that make life on Earth possible, and briefly explain one of them.
State two functions of the atmosphere that make life on Earth possible, and briefly explain one of them.
A closed car in the sun gets much hotter inside than the air on the street. Light comes in through the windows, but heat has a hard time getting out. The atmosphere does something similar for the Earth. How does it manage this if almost all the air is nitrogen and oxygen?
First, three words that do not mean the same thing:
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A classmate claims that it is absurd to attribute global warming to carbon dioxide ($\text{CO}2$), since making up only 0.04 % of the air, nitrogen (78 %) and oxygen (21…
A classmate claims that it is absurd to attribute global warming to carbon dioxide ($\text{CO}_2$), since making up only 0.04 % of the air, nitrogen (78 %) and oxygen (21 %) must be the real culprits responsible for trapping heat. Refute their position by explaining the differential behavior of these gases toward solar radiation and terrestrial infrared radiation, and predict what would happen to the planet's average temperature if $\text{CO}_2$ and the other greenhouse gases were to disappear entirely.
Back to the beginning: as you go up the mountain it gets colder because in the troposphere the temperature decreases with altitude, and you feel short of air because at lower pressure each breath brings in fewer oxygen molecules.
Summary
Let's practice! 3 medium exercises in this section