14 - Earth’s Atmosphere and Meteorology

Question 1

Define:

atmosphere

Answer 1

A layer of gases surrounding Earth.

The atmosphere regulates temperature, blocks harmful solar radiation, and is vital for sustaining life on Earth by enabling processes like respiration and the water cycle.

Question 2

Explain:

What are the primary functions of the Earth’s atmosphere?

Answer 2

• Provides oxygen and carbon dioxide for life.
• Regulates Earth’s temperature.
• Shields against harmful radiation.
• Facilitates weather and climate.

Question 3

True or False:

The atmosphere is composed mainly of oxygen.

Answer 3

False

The atmosphere is 78% nitrogen, 21% oxygen, and 1% other gases like argon and CO₂.

Question 4

Explain:

What are the main layers of the atmosphere?

Answer 4

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere

Troposphere – The layer closest to Earth where weather happens and clouds form.

Stratosphere – Contains the ozone layer, which protects us from the sun’s harmful rays.

Mesosphere – The coldest layer, where meteors burn up and create shooting stars.

Thermosphere – A very hot layer with the ionosphere, where auroras and radio signals occur.

Exosphere – The outermost layer, where satellites orbit and space begins.

Question 5

Define:

ozone layer

Answer 5

The layer responsible for absorbing harmful UV radiation.

The ozone layer, located in the stratosphere, absorbs 97-99% of the Sun’s harmful UV radiation, protecting life on Earth.

Question 6

Explain:

Why is the thermosphere important for communication?

Answer 6

It contains the ionosphere, which reflects radio waves.

The thermosphere (80–700 km) has ionized particles that enable radio signal transmission and is where auroras occur.

Question 7

True or False:

The mesosphere is the coldest layer of the atmosphere.

Answer 7

True

Temperatures in the mesosphere can drop as low as -90°C (-130°F). It burns up meteors before they reach Earth.

Question 8

Identify:

What protects Earth by deflecting solar wind?

Answer 8

Magnetosphere

Controlled by Earth’s magnetic field, it shields the planet from harmful cosmic radiation and prevents atmospheric erosion.

Question 9

Identify:

What boundary at 100 km marks the edge of space?

Answer 9

Kármán Line

Recognized internationally, the Kármán Line is where aerodynamics end, and astronautics begin, defining the start of space travel.

Question 10

Explain:

What is the role of nitrogen in the atmosphere?

Answer 10

It supports plant growth through the nitrogen cycle.

Atmospheric N₂ is converted into useful compounds (nitrates) by bacteria, supporting agriculture and ecosystems.

Question 11

Identify:

What is the primary source of atmospheric oxygen?

Answer 11

Photosynthesis by plants and phytoplankton.

50-80% of oxygen is produced by oceanic phytoplankton, with forests contributing the rest.

Question 12

Enumerate:

What are the major biogeochemical cycles involving the atmosphere?

Answer 12

• Carbon Cycle
• Nitrogen Cycle
• Water Cycle
• Oxygen Cycle

Carbon Cycle – Transfers carbon between the atmosphere, living things, and the ocean.

Nitrogen Cycle – Converts atmospheric nitrogen into nutrients essential for life.

Water Cycle – Moves water through evaporation, clouds, rain, and groundwater.

Oxygen Cycle – Circulates oxygen for breathing, combustion, and plant growth.

Question 13

Explain:

How does the atmosphere influence the water cycle?

Answer 13

It enables evaporation, condensation, and precipitation.

The troposphere drives weather patterns, moving water across ecosystems through cloud formation and rainfall.

Question 14

Define

greenhouse gases

Answer 14

Gases that trap heat in the atmosphere.

Examples include CO₂, CH₄, H₂O vapor, and N₂O, which regulate Earth’s temperature but contribute to climate change when excessive.

Question 15

Describe:

The relationship between CO₂ and climate change.

Answer 15

Excess CO₂ traps heat, raising global temperatures.

Human activities like fossil fuel burning increase CO₂, leading to extreme weather and rising sea levels.

Question 16

True or False:

The atmosphere has no effect on Earth’s temperature.

Answer 16

False

The greenhouse effect moderates Earth’s temperature, preventing extreme heat loss at night.

Question 17

Identify:

What harmful rays from the Sun does the ozone layer absorb?

Answer 17

Ultraviolet

The ozone layer absorbs most UV-B and nearly all UV-C rays, protecting life from harmful radiation that can cause skin cancer, cataracts, and environmental damage. Some UV-A rays still reach Earth’s surface but are less harmful.

Question 18

Define:

meteorology

Answer 18

The scientific study of the atmosphere and weather.

Meteorology examines atmospheric temperature, pressure, humidity, cloud formation, and weather systems to predict and understand climate patterns.

Question 19

Explain:

What are the three fundamental meteorological variables?

Answer 19

1. Temperature
2. Pressure
3. Humidity

Temperature: Measures how hot or cold the air is.

Pressure: The weight of air pushing down.

Humidity: The amount of water vapor in the air.

Question 20

True or False:

Meteorology only focuses on short-term weather patterns.

Answer 20

False

Meteorology includes both short-term (weather forecasting) and long-term (climatology) studies.

Question 21

Define:

atmospheric pressure

Answer 21

The force exerted by air on Earth’s surface.

Atmospheric pressure decreases with altitude, affecting weather, breathing, and flight.

Question 22

Explain:

Why does atmospheric pressure decrease with altitude?

Answer 22

Fewer air molecules are present as altitude increases.

Gravity pulls most air molecules closer to Earth’s surface, making the air denser at lower altitudes. Higher altitudes have thinner air, affecting breathing, weather, and aviation.

Question 23

Identify:

What instrument is used to measure atmospheric pressure?

Answer 23

barometer

Mercury and aneroid barometers help forecast weather by detecting pressure changes. Falling pressure usually means rain, while rising pressure signals clear skies.

Question 24

Explain:

Why do high and low-pressure systems form?

Answer 24

Uneven heating of Earth’s surface causes air movement.

High pressure brings clear weather, while low pressure leads to clouds and storms.

Question 25

# Fill in the blank: The **scientific study** of long-term atmospheric patterns is called \_\_\_\_\_\_\_\_.

Answer 25

climatology ## Footnote **Climatology** examines weather trends over decades or centuries, unlike meteorology, which focuses on short-term weather.

Question 26

# Fill in the blank: The **primary source** of atmospheric heat is the \_\_\_\_\_\_.

Answer 26

sun ## Footnote Solar radiation is the **driving force** behind weather patterns, ocean currents, and temperature variations on Earth.

Question 27

# Identify: What is the term for the **amount of water vapor** in the air?

Answer 27

Humidity ## Footnote Higher humidity *increases cloud formation* and affects temperature perception (e.g., heat index).

Question 28

# Identify: What instrument **measures** humidity?

Answer 28

hygrometer ## Footnote Psychrometers and digital hygrometers measure moisture levels in the air to help predict precipitation.

Question 29

# Explain: What are the **main global wind patterns**?

Answer 29

* Trade Winds * Westerlies * Polar Easterlies ## Footnote **Trade Winds** – Steady winds that blow from east to west near the equator. **Westerlies** – Winds that move from west to east in the mid-latitudes. **Polar Easterlies** – Cold winds blowing from east to west near the poles.

Question 30

# Fill in the blank: The **temperature** at which air becomes **saturated** is called the \_\_\_\_\_ \_\_\_\_\_\_\_.

Answer 30

Dew point ## Footnote When air cools to the **dew point**, excess moisture condenses into clouds, dew, or fog.

Question 31

# Define: clouds

Answer 31

Masses of tiny water droplets or ice crystals in the air. ## Footnote Clouds form when air **cools**, causing water vapor to condense. Their formation depends on humidity, air movement, and temperature changes.

Question 32

# Expain: What are the **main types of clouds**?

Answer 32

* Cirrus * Cumulus * Stratus * Nimbus ## Footnote **Cirrus** – Thin clouds found very high in the sky, often looking like streaks. **Cumulus** – White, puffy clouds that look like cotton and usually mean good weather. **Stratus** – Low clouds that spread across the sky and make it look gray. **Nimbus** – Dark clouds that bring heavy rain or storms.

Question 33

# Identify: What **type of cloud** is associated with thunderstorms?

Answer 33

Cumulonimbus clouds ## Footnote *Cumulonimbus clouds* are large, towering clouds that can produce severe weather, including thunderstorms and tornadoes.

Question 34

# Define: air mass

Answer 34

A large body of air with **uniform temperature** and **humidity**. ## Footnote Air masses move and interact, forming fronts and weather systems.

Question 35

# Identify: What is the term for the **boundary** between **two air masses**?

Answer 35

front ## Footnote A **front** is where two air masses meet and interact, leading to changes in weather conditions such as *temperature*, *humidity*, and *precipitation*.

Question 36

# Explain: What are the **four main types** of weather fronts?

Answer 36

1. Cold Front 2. Warm Front 3. Stationary Front 4. Occluded Front ## Footnote **Cold Front** – Cold air moves into a warmer air mass and causes storms. **Warm Front** – Warm air moves over cold air and brings gradual precipitation. **Stationary Front** – Two air masses meet and do not move leading to prolonged clouds and rain. **Occluded Front** – A cold front catches up to a warm front and creates complex weather.

Question 37

# True or False: A warm front brings **rising cool air** and often results in **fair weather**.

Answer 37

False ## Footnote A warm front is associated with *rising warm air* and often leads to cloud formation and precipitation as the warm air rises over the cooler air.

Question 38

# Identify What kind of front forms when a cold air mass **overtakes** a warm air mass?

Answer 38

cold ## Footnote *Cold fronts* typically bring thunderstorms and a sudden drop in temperature.

Question 39

# True or False: Tornadoes form **over** warm ocean waters.

Answer 39

False ## Footnote **Tornadoes** form over land in strong thunderstorms, while hurricanes form over oceans.

Question 40

# Explain: How do **tornadoes** form?

Answer 40

Cold, dry air meets warm, moist air, creating rotation. ## Footnote Tornadoes are formed in *supercell thunderstorms* and can have wind speeds exceeding 300 mph.

Question 41

# Identify: What is the **strongest type** of storm system on Earth?

Answer 41

A hurricane | (or typhoon) ## Footnote **Hurricanes** form over warm ocean waters and can produce winds over 157 mph (252 km/h).

Question 42

# Explain: What does a **weather satellite** do?

Answer 42

Monitors **cloud patterns**, **storms**, and **climate**. ## Footnote Satellites provide *real-time images* to track hurricanes, weather fronts, and atmospheric changes.