Gr 9 NATURAL SCIENCES: CH 4.4 The stratosphere

What percentage of the atmosphere's mass is contained in the troposphere and stratosphere together?

50%
70%
90% (correct)
95%

What is the primary reason commercial airplanes fly in the lower stratosphere?

Because of the higher air density
To get closer to the mesosphere
To reduce air resistance
To avoid turbulence (correct)

What do weather balloons carry to gather data on atmospheric conditions?

Thermometers
Barometers
GPS trackers
Radiosondes (correct)

What is the primary function of the ozone layer in the stratosphere?

To absorb harmful ultraviolet rays (A) Signup and view all the answers

What is the temperature trend in the stratosphere?

It increases with altitude (C) Signup and view all the answers

What were CFCs commonly used in?

Aerosols, refrigerants, and industrial processes (C) Signup and view all the answers

What is the primary consequence of chlorine atoms reacting with ozone molecules?

Reduction of the ozone layer's ability to absorb UV radiation (C) Signup and view all the answers

What is the term for the thinning of the ozone layer, particularly over Antarctica?

Ozone hole (D) Signup and view all the answers

What is the result of a thinner ozone layer?

More UV radiation reaches the Earth's surface (A) Signup and view all the answers

What led to a global ban on CFCs?

Discovery of the ozone hole (D) Signup and view all the answers

What is the primary characteristic of the air in the stratosphere compared to the troposphere?

Less turbulent and less dense (B) Signup and view all the answers

What is the purpose of the instruments carried by weather balloons?

To transmit information on atmospheric conditions (C) Signup and view all the answers

What is the source of the ozone layer's ability to absorb harmful ultraviolet radiation?

The formation and destruction of ozone molecules (D) Signup and view all the answers

What is the result of the ozone layer's presence on the temperature in the stratosphere?

The temperature increases with altitude (C) Signup and view all the answers

What is the altitude range of the stratosphere above the Earth's surface?

12 km to 50 km (A) Signup and view all the answers

What is the role of chlorine atoms in the stratosphere?

They catalytically destroy ozone molecules. (B) Signup and view all the answers

What is the primary mechanism by which CFCs deplete the ozone layer?

They release chlorine atoms that catalytically destroy ozone molecules. (D) Signup and view all the answers

What is the consequence of a decrease in the ozone layer's ability to absorb UV radiation?

More UV radiation reaches the Earth's surface. (C) Signup and view all the answers

What led to the global ban on CFCs?

Their contribution to the thinning of the ozone layer (D) Signup and view all the answers

Where is the thinning of the ozone layer most pronounced?

Over Antarctica (C) Signup and view all the answers

What is the primary reason the stratosphere is more stable than the troposphere?

There is minimal turbulence in the stratosphere (C) Signup and view all the answers

What is the primary mechanism by which ozone molecules are formed in the stratosphere?

Ozone molecules form through the reaction of oxygen molecules and UV light (B) Signup and view all the answers

What is the primary characteristic of the temperature gradient in the stratosphere?

The temperature increases with altitude (C) Signup and view all the answers

What is the primary function of radiosondes carried by weather balloons?

To transmit information on temperature, humidity, and wind speed (A) Signup and view all the answers

What is the primary reason the stratosphere is divided into distinct layers?

The stratosphere is divided into layers due to the presence of the ozone layer (C) Signup and view all the answers

What is the primary reactant that chlorine atoms from CFCs catalytically destroy in the stratosphere?

Ozone molecules (D) Signup and view all the answers

What is the primary environmental consequence of the depletion of the ozone layer?

Increased risk of skin cancer (B) Signup and view all the answers

What is the primary mechanism by which CFCs are able to catalytically destroy ozone molecules?

Catalytic reaction (A) Signup and view all the answers

What is the primary region where the thinning of the ozone layer is most pronounced?

Over Antarctica (B) Signup and view all the answers

What is the primary international response to the discovery of the ozone hole?

Global ban on CFCs (D) Signup and view all the answers