4B5 Earth's Atmosphere

Question 1

What is the Earth’s atmosphere?

Answer 1

A layer of gases surrounding the planet.

The atmosphere protects life on Earth by providing oxygen, regulating temperature, and blocking harmful solar radiation.

Question 2

What are the four layers of Earth’s atmosphere?

Answer 2

1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere

Each layer has unique properties and functions, such as weather in the troposphere and UV protection in the stratosphere.

Question 3

Fill in the blank:

The atmosphere is primarily composed of _________ and oxygen.

Answer 3

nitrogen

Nitrogen makes up 78% of the atmosphere, while oxygen accounts for 21%. The remaining 1% consists of trace gases.

Question 4

True or False:

The atmosphere is vital for supporting life on Earth.

Answer 4

True

It provides essential gases like oxygen, regulates Earth’s temperature, and shields the planet from harmful solar radiation.

Question 5

What is the approximate percentage of argon in the Earth’s atmosphere?

Answer 5

About 0.93%.

Argon is a noble gas that contributes to the trace components of the atmosphere but has little effect on atmospheric processes.

Question 6

What is the primary function of the ozone layer?

Answer 6

To block harmful ultraviolet (UV) radiation.

Ozone molecules (O₃) in the stratosphere absorb and prevent most UV-B and all UV-C radiation from reaching Earth’s surface.

Question 7

Fill in the blank:

The layer of the atmosphere where most meteors burn up is the __________.

Answer 7

Mesosphere

The mesosphere lies above the stratosphere and below the thermosphere, reaching temperatures as low as -90°C.

Question 8

True or False:

The thermosphere is the hottest layer of the atmosphere.

Answer 8

True

Temperatures in the thermosphere can reach up to 2,500°C due to the absorption of high-energy solar radiation, though it feels cold due to low air density.

Question 9

What is the boundary between the troposphere and stratosphere called?

Answer 9

Tropopause

The tropopause acts as a barrier, preventing the mixing of air between the troposphere and stratosphere.

Question 10

What is the uppermost layer of the atmosphere?

Answer 10

Exosphere

The exosphere extends from the thermosphere to outer space and is where molecules are sparse, gradually transitioning into space.

Question 11

What gas in the stratosphere causes temperature to rise with altitude?

Answer 11

Ozone

(O₃)

Ozone absorbs UV radiation, causing temperatures to rise in the upper stratosphere.

Question 12

True or False:

The stratosphere is the coldest layer of the atmosphere.

Answer 12

False

The mesosphere is the coldest layer, with temperatures dropping as low as -90°C.

Question 13

Fill in the blank:

The chemical formula of ozone is ______.

Answer 13

O₃

Ozone molecules are composed of three oxygen atoms and are crucial for absorbing UV radiation in the stratosphere.

Question 14

Which atmospheric layer is known for its weather-related activity?

Answer 14

Troposphere

The troposphere is the most dynamic layer, with storms, clouds, and precipitation driven by the Earth’s heat and water cycle.

Question 15

What is absolute humidity?

Answer 15

The total amount of water vapor in the air.

Absolute humidity is measured in grams of water per cubic meter of air and represents the actual water vapor content in the air.

Question 16

What is the percentage of water vapor in air?

Answer 16

Relative humidity

Relative humidity is affected by both water vapor content and air temperature.

Question 17

True or False:

Warm air can hold more water vapor than cold air.

Answer 17

True

As temperature increases, the air’s capacity to hold water vapor also increases, which affects relative humidity.

Question 18

Fill in the blank:

When air reaches 100% relative humidity, it is said to be _________.

Answer 18

saturated

At saturation, condensation occurs, leading to cloud formation or precipitation.

Question 19

How is relative humidity measured?

Answer 19

Using a hygrometer.

Hygrometers measure the water vapor content in the air and calculate the relative humidity percentage.

Question 20

What are the three main types of clouds?

Answer 20

1. Cumulus
2. Stratus
3. Cirrus

Cumulus clouds are puffy, stratus clouds are layered, and cirrus clouds are wispy and high-altitude.

There are many more specific kinds of clouds, such as cirrocumulus or nimbostratus, but these classifications are the most general.

Question 21

Fill in the blank:

Clouds form when warm, moist air ________ and cools, causing condensation.

Answer 21

rises

As air rises and cools, the water vapor condenses into tiny droplets or ice crystals, forming clouds.

Question 22

What type of cloud is associated with thunderstorms?

Answer 22

Cumulonimbus

Cumulonimbus clouds are tall and dense, capable of producing heavy rain, lightning, and severe weather.

Question 23

Which clouds are the highest in the atmosphere?

Answer 23

Cirrus clouds

Cirrus clouds form in the upper troposphere and are made of ice crystals due to cold temperatures.

Question 24

True or False:

Stratus clouds are often responsible for overcast skies.

Answer 24

True

Stratus clouds cover large areas of the sky and typically produce light rain or drizzle.

Question 25

What are the **four** main types of precipitation?

Answer 25

1. Rain 2. Snow 3. Sleet 4. Hail ## Footnote Precipitation forms when water droplets or ice crystals grow large enough to fall to the ground. The kind of precipitation that occurs depends on the temperature at different altitudes.

Question 26

# Fill in the blank: \_\_\_\_\_\_\_\_ forms when rain **freezes** while falling through cold air near the ground.

Answer 26

Sleet ## Footnote **Sleet** starts as rain but freezes into ice pellets before reaching the surface.

Question 27

How does **hail** form?

Answer 27

By **repeated updrafts** in a thunderstorm. ## Footnote **Hailstones** grow as they are carried up and down by strong winds in cumulonimbus clouds. A cycle of freezing and collision with water droplets allows the hail to grow larger and larger. Eventually, it will become too heavy, and precipitate to the ground.

Question 28

# True or False Snow forms when water vapor sublimates **directly** into ice crystals.

Answer 28

True ## Footnote Snow forms in cold clouds where temperatures are below freezing, bypassing the liquid phase.

Question 29

What is **barometric pressure**?

Answer 29

The **force exerted** by the weight of the air. ## Footnote Barometric pressure is measured using a barometer and influences weather patterns.

Question 30

What is a **sea breeze**?

Answer 30

Wind blowing from the **sea to the land**. ## Footnote Sea breezes occur during the day when land heats faster than water, creating a pressure difference.

Question 31

# Fill in the blanks: Wind moves from areas of \_\_\_\_\_\_ pressure to \_\_\_\_\_\__ pressure.

Answer 31

High; low ## Footnote This movement is caused by pressure differences in the atmosphere, driving air circulation.

Question 32

What is a **land breeze**?

Answer 32

Wind blowing from the **land to the sea**. ## Footnote Land breezes occur at night when the land cools faster than the sea, reversing the pressure difference.

Question 33

What is an **air mass**?

Answer 33

A **large body of air** with uniform temperature and humidity. ## Footnote Air masses are classified based on their source regions, such as polar or tropical.

Question 34

# Fill in the blank: A \_\_\_\_\_\_ front forms when warm air **meets** and rises over cold air.

Answer 34

warm ## Footnote *Warm fronts* often bring light rain followed by warmer, clearer weather.

Question 35

What does a **blue** line with triangles on a weather map indicate?

Answer 35

A cold front. ## Footnote The triangles point in the direction the cold air is moving.

Question 36

# Fill in the blank: H on a **weather map** represents \_\_\_\_\_\_ pressure, while L represents \_\_\_\_\_\_ pressure.

Answer 36

High; low ## Footnote *High pressure* is associated with clear weather, while *low pressure* often brings storms.

Question 37

# True or False: Radar is used to **detect** precipitation intensity and location.

Answer 37

True ## Footnote **Radar** systems use radio waves to identify the size, location, and movement of precipitation.

Question 38

How does latitude **affect** climate?

Answer 38

It determines the **amount** of solar energy received. ## Footnote Regions near the equator receive more *direct sunlight*, leading to warmer climates, while higher latitudes receive *less sunlight*, resulting in cooler climates.

Question 39

What is the **rain shadow effect**?

Answer 39

The **dry area** on the leeward side of a mountain. ## Footnote Moist air loses moisture as it rises over a mountain, causing rain on the windward side. The dry air descending on the leeward side creates the rain shadow effect, often forming deserts like the Great Basin.

Question 40

# True or False: Elevation **decreases** temperature.

Answer 40

True ## Footnote As altitude increases, air pressure and temperature decrease, leading to cooler conditions at higher elevations.

Question 41

What are **global wind belts**?

Answer 41

Large-scale **patterns** of wind movement. ## Footnote These wind belts, including trade winds, westerlies, and polar easterlies, distribute heat and moisture globally, shaping weather and climate.

Question 42

What is the **deflection of winds** due to Earth’s rotation called?

Answer 42

The Coriolis effect. ## Footnote The Coriolis effect *causes* winds and ocean currents to curve due to Earth’s rotation, deflecting to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Question 43

# True or False: Trade winds **blow** from east to west in the Tropics.

Answer 43

True ## Footnote *Trade winds* result from atmospheric circulation and are critical for distributing heat and moisture globally.

Question 44

What are the main **climate zones** on Earth?

Answer 44

1. Tropical 2. Temperate 3. Polar ## Footnote *Climate zones* are determined by latitude: tropical near the equator, temperate with moderate temperatures and seasons, and polar near the poles with cold temperatures and low precipitation.

Question 45

# Fill in the blanks: The **Arctic** climate zone has \_\_\_\_\_ temperatures and \_\_\_\_\_ precipitation.

Answer 45

cold; low ## Footnote The Arctic zone is dominated by ice and tundra landscapes, with extreme seasonal variations in daylight.

Question 46

Which climate zone is **located** between 66.5°N and 90°N?

Answer 46

Polar ## Footnote The *polar climate zone* experiences extreme cold and long periods of darkness or daylight due to its high latitude.

Question 47

How do volcanic eruptions **affect** climate?

Answer 47

They release **particles** that cool the Earth. ## Footnote Volcanic *aerosols*, like sulfur dioxide, reflect sunlight and temporarily lower global temperatures.

Question 48

What is the **impact** of variations in solar radiation on climate?

Answer 48

They cause temperature **fluctuations**. ## Footnote Changes in solar output, such as during solar cycles, can influence long-term climate patterns.

Question 49

# True or False: El Niño events **lead** to warmer ocean temperatures in the Pacific.

Answer 49

True ## Footnote *El Niño* disrupts global weather patterns, causing droughts in some areas and floods in others.

Question 50

How do human activities **amplify** natural climate changes?

Answer 50

By **increasing** greenhouse gas emissions. ## Footnote Burning fossil fuels and deforestation add *carbon dioxide* to the atmosphere, intensifying natural warming effects.