Earth’s Processes: Climate and Weather (Unit 2)

Question 1

What is the extent of the atmosphere and what is its purpose?

Answer 1

Earth’s atmosphere extends from the surface of the planet into outer space. It shields life on Earth from the harsh conditions of space

Question 2

Atmosphere Definition

Answer 2

The envelope of gases and small particles that surround Earth

Question 3

How do the different ways in which energy from the sun is absorbed by the different layers of the atmosphere influence the types of energy that reaches Earth’s surface?

Answer 3

Energy from the sun is absorbed in different ways by each layer of the atmosphere, affecting how much and what types of energy reach Earth’s surface

Question 4

What are the characteristics of the first layer of the atmosphere, the troposphere?

Answer 4

Earth’s surface absorbs heat from the sun and radiates some of it back. This means that the first layer of Earth’s atmosphere, the troposphere, is warmest close to Earth’s surface and becomes cooler as altitude increases. Because there is warm air near Earth’s surface and cooler air above it, there is vertical air circulation in this layer

Question 5

Troposphere Definition

Answer 5

The layer of the atmosphere closest to Earth’s surface

Question 6

In which layer does almost all weather, including clouds, occur? How does the speed of wind differ with altitude?

Answer 6

Almost all weather, including clouds, occurs in the troposphere. Winds at ground level are slower than they are at high altitude due to friction with Earth’s surface

Question 7

What are the characteristics of the second layer of the atmosphere, the stratosphere?

Answer 7

At the top of the troposphere, the boundary with the stratosphere is marked by a region of air at a constant temperature. Above this level, temperatures in the stratosphere increase with elevation. Because the warmer air is already atop the colder air, there is little vertical circulation of air in this layer. Instead, it is marked by strong horizontal winds.

Question 8

Stratosphere Definition

Answer 8

The layer of the Earth’s atmosphere above the troposphere

Question 9

What kind of clouds can be formed in the stratosphere?

Answer 9

Wispy clouds made of ice and super cooled water can form in the stratosphere, which is very dry

Question 10

Why does the temperature in the stratosphere increase as altitude increases?

Answer 10

When oxygen molecules in the stratosphere absorb ionizing radiation, they break apart, forming ozone. Ozone is an oxygen molecule with three oxygen atoms rather than two. Ozone absorbs ultraviolet radiation, shielding life on Earth from the effects of this radiation. Heat from absorbing this radiation accounts for the increase in temperature with altitude in this atmospheric layer.

Question 11

What are some forms of ionizing radiation? How do they interact with the atmosphere (absorption) and atoms?

Answer 11

Gamma rays, x-rays, and higher-energy ultraviolet rays are all forms of ionizing radiation. They are largely absorbed by the atmosphere before they reach Earth’s surface. Atoms can absorb Ionizing radiation, which can free electrons from those atoms, ionizing them.

Question 12

What happens when atoms are ionized? Why does ionizing radiation pose a threat to living things?

Answer 12

When atoms are ionized they become reactive. Ionization disrupts molecular bonds, which can damage cells in living things. Ionizing radiation is dangerous to life on Earth and to astronauts working outside Earth’s protective atmosphere.

Question 13

What two characteristics do ionizing radiation have?

Answer 13

High frequency and low wavelength

Question 14

What are the characteristic of the third, middle layer of the atmosphere, the mesosphere?

Answer 14

Above the stratosphere is the mesosphere. As in the troposphere, temperature decreases with altitude, so there is vertical mixing of gases in this layer.

Question 15

Mesosphere Definition

Answer 15

Middle layer of the atmosphere

Question 16

What kind of clouds can form in the mesosphere?

Answer 16

Ice crystal clouds can form in the mesosphere

Question 17

Under what circumstances can clouds in the mesosphere form?

Answer 17

Clouds can form in the mesosphere in rare circumstances. In recent years, an increase in methane at high altitude has led to an increase in water vapor. This water vapor can form more high-altitude clouds that are visible at night.

Question 18

What are the characteristics of the fourth layer of the atmosphere, the thermosphere?

Answer 18

At the transition from mesosphere to thermosphere, temperature again increases with elevation. Temperatures in this layer are strongly affected by solar activity and can vary widely. This is the hottest region of the atmosphere. Most incoming X-rays and gamma rays are absorbed by this layer, which is highly ionized. As in the stratosphere, the absorption of radiation leads to higher temperatures at higher elevation in this layer. It is too dry and warm for clouds. Auroras occur in this layer.

Question 19

Thermosphere Definition

Answer 19

The hottest and most ionized layer of Earth’s atmosphere

Question 20

What are the characteristics of the last layer of the atmosphere, the exosphere?

Answer 20

Beyond the thermosphere lies the exosphere, where the atmosphere is very thin and doesn’t behave like a normal gas. Atoms and molecules may travel for miles before colliding with other particles, or these particles might escape Earth altogether. The rate of loss of molecules through the exosphere determines whether a planet retains its atmosphere.

Question 21

Exosphere Definition

Answer 21

The outermost layer of Earth’s atmosphere

Question 22

Why would the thermosphere feel cool to exposed skin?

Answer 22

Because the air is so thin

Question 23

In which layer of the atmosphere do we live in?

Answer 23

The troposphere

Question 24

Three-fourths of the mass in the atmosphere is found in which layer?

Answer 24

The troposphere

Question 25

Ozone is abundant in which layer of the atmosphere?

Answer 25

The stratosphere

Question 26

Airplanes and weather balloons fly in which layer of the atmosphere?

Answer 26

The stratosphere

Question 27

Where is the coldest part of the atmosphere?

Answer 27

At the top of the mesosphere

Question 28

In which layer of the atmosphere do meteors burn?

Answer 28

In the mesosphere

Question 29

Why is the mesosphere difficult to study?

Answer 29

The mesosphere is difficult to study since planes and weather balloons cannot reach it and spacecrafts and satellites orbit above it

Question 30

Is the density of the thermosphere high or low?

Answer 30

The thermosphere has a very low density

Question 31

True or False: the exosphere is very thin and some argue it is not apart of the atmosphere

Answer 31

True

Question 32

What is the distribution of solar energy, along the electromagnetic spectrum, that reaches Earth?

Answer 32

About half of the solar energy that reaches Earth is in the form of visible light waves. The rest is mostly in the form of higher-energy UV radiation and lower-energy infrared radiation

Question 33

True or False: Infrared radiation includes the thermal energy that can be felt as heat

Answer 33

True

Question 34

What is the difference between electromagnetic waves and mechanical waves?

Answer 34

Electromagnetic waves can travel through empty space, while mechanical waves, such as sound waves , water waves, and seismic waves, can only travel through matter

Question 35

How much of solar energy do clouds and gases in the atmosphere absorb and reflect? How is energy from the surface redistributed to the atmosphere?

Answer 35

Clouds and gases that make up the atmosphere absorb about a fourth of the solar energy that reaches Earth and reflect about another fourth of the energy back out to space. Much of the solar energy that reaches Earth’s surface is also redistributed back to the atmosphere. Some energy is carried to the atmosphere by evaporation of surface water. The water vapor stores energy in the atmosphere. The atmosphere absorbs energy from thermal infrared radiation from the ground. Energy in the atmosphere is circulated by convection, as heated air rises and cooler air sinks.

Question 36

What are examples of conditions that make up weather?

Answer 36

Precipitation, temperature, humidity cloudiness, and wind are examples of conditions that make up the weather in an area

Question 37

Weather Definition

Answer 37

Atmospheric conditions at a specific time and place

Question 38

How do changes in energy in different parts of the atmosphere form wind and storm systems?

Answer 38

Changes in energy in different parts of the atmosphere can produce winds and cause storm systems to form. As the air near Earth’s surface warms, it rises, cools, and releases energy. Moisture in the cooling air condenses, forming clouds and eventually precipitation. Winds and storm systems can form as higher-density cool air moves in under the lower-density, rising warm air.

Question 39

How is the sun a source of energy for tornadoes and hurricanes?

Answer 39

The source of energy for all storm systems, including tornadoes and hurricanes, is electromagnetic energy from the sun. This energy is absorbed partly by the atmosphere but mainly by land and water. It is then redistributed to the atmosphere where it provides energy in the rising warm, moist air in tornadoes, hurricanes, and all other storm systems.

Question 40

Remember: The sun’s heating of air, land, and water produces predictable changes in air masses. Most of the changes are based on warm, less dense air rising and cooler, denser air falling. The movement of these air masses affects the weather as they move through an area. The systems can be cold or hot, and dry or moist.

Answer 40

The sun’s heating of air, land, and water produces predictable changes in air masses. Most of the changes are based on warm, less dense air rising and cooler, denser air falling. The movement of these air masses affects the weather as they move through an area. The systems can be cold or hot, and dry or moist.

Question 41

What are the different types of fronts?

Answer 41

Stationary front, occluded front, cold front, and warm front

Question 42

What are the characteristics of a tornado?

Answer 42

A tornado is a column of rapidly spinning, rising air. Tornadoes form during thunderstorms when winds cause a strong updraft near the ground to swirl. Tornadoes often remain in an area just a few minutes. While winds within the strongest tornadoes swirl at speeds up to 320 kph (200 mph), the tornado itself moves more slowly, usually about 20 to 30 kph (12 to 19 mph). Tornadoes usually dissipate after moving less than 10 km (6 mi).

Question 43

What are the characteristics of a hurricane?

Answer 43

A hurricane is a large storm system with intense, swirling winds and heavy rain. In some parts of the world, they are called typhoons or cyclones. Hurricanes form near the equator when ocean water, warmed by solar energy, heats the overlying air. The lower density of the warm air causes it to rise. Colliding winds can begin to swirl. The storm system grows as more energy and moisture are drawn into the air. Global winds in the lower latitudes typically cause hurricanes to move east to west. The systems can cause severe damage as they move over land, particularly if the areas are inhabited. Cooler temperatures, lack of moisture, and friction between the air and land decrease the strength of a hurricane as it moves over land.

Question 44

Air mass Definition

Answer 44

A large body of air with similar temperature and humidity

Question 45

Front Definition

Answer 45

The boundary between air masses

Question 46

What does climate consist of?

Answer 46

Climate consists of averages, such as average yearly temperature and average monthly precipitation in an area.

Question 47

How does the Earth’s tilt and rotation influence climate?

Answer 47

Because of Earth’s tilt, the sun’s rays are more intense at the equator. Air is heated more near the equator than at higher latitudes. As Earth spins on its axis, it moves under the overlying air. This movement, along with the uneven heating, produces a system of rising and falling air currents and a pattern of global winds. The air currents gain moisture over the ocean, carrying it to other areas where it falls again as precipitation. Areas experience changing climates throughout the year because of the change in orientation of Earth as it orbits the sun.

Question 48

Climate Definition

Answer 48

A pattern of atmospheric conditions over a long period of time

Question 49

True or False: Texture and color on Earth affect the level of absorption and reflection. Dark-colored objects absorb more radiation, and light-colored objects reflect more radiation.

Answer 49

True

Question 50

What is albedo? What is Earth’s average albedo?

Answer 50

The percentage of solar radiation reflected back into space is called albedo. Earth’s average albedo is about 0.3, meaning about 30 percent of incoming solar energy is reflected back into space, and 70 percent is absorbed.

Question 51

Remember: The absorbed energy is transformed into heat energy. This helps regulate the temperature of Earth’s crust, surface waters, and the lower atmosphere. The absorption drives photosynthesis, fuels evaporation, melts snow and ice, and warms Earth.

Answer 51

The absorbed energy is transformed into heat energy. This helps regulate the temperature of Earth’s crust, surface waters, and the lower atmosphere. The absorption drives photosynthesis, fuels evaporation, melts snow and ice, and warms Earth.

Question 52

Remember: Glaciers and ice sheets reflect back a high percentage of the radiation hitting their surfaces. This prevents additional heat from being absorbed by water or land, making it a colder climate. However, as Earth continues to warm, the ice has decreased, causing more warming and melting.

Answer 52

Glaciers and ice sheets reflect back a high percentage of the radiation hitting their surfaces. This prevents additional heat from being absorbed by water or land, making it a colder climate. However, as Earth continues to warm, the ice has decreased, causing more warming and melting.

Question 53

How do land and water differ in their ways of absorbing and reflecting light?

Answer 53

Earth’s surface is divided into land and water. In the water, light can be transmitted down tens of meters, absorbed into a thick layer of material. On land the surfaces are usually opaque to visible light, and so the incoming energy is not transmitted down into deeper layers. Instead, the land surface either reflects the incoming electromagnetic energy back into the atmosphere, or absorbs the energy in a thin layer at the surface.

Question 54

Opaque Definition

Answer 54

Absorbing or reflecting all of the incident electromagnetic energy

Question 55

How does absorbed electromagnetic energy produce heat in surfaces? How does heat transfer between the Earth’s surface and atmosphere?

Answer 55

When electromagnetic energy is absorbed by a surface, it excites the atoms or molecules in that surface, raising the surface’s temperature. If the surface is hotter than the air above it, then heat will transfer from the surface back into the atmosphere until the two are again in equilibrium. If the air is warmer than the land surface, then the energy transfer will go the other direction, and heat will be conducted from the air into the top layer of the ground until it is the same temperature as the air.

Question 56

Why does air just above a hot surface sometimes seem to shimmer?

Answer 56

The air just above a hot surface sometimes seems to shimmer. This is due to the hot surface transferring heat to the atmosphere just above it. The heated air transmits light differently than the cooler air above, leading to the haze or shimmer.

Question 57

What are the three ways in which electromagnetic radiation flows out from the land and into the atmosphere?

Answer 57

— The evaporation of water uses energy. When water molecules at the surface absorb energy to change from liquid to gas, the energy used to evaporate the water is latent in the motion of the water vapor molecules. When the water vapor condenses again at high altitude, the heat is released into the atmosphere.

— A hot surface will heat the cooler air just above itself. The warmer air will rise in convection, carrying heat away from the ground.

— Any object not at absolute zero will radiate thermal, or infrared, radiation. It will also absorb or reflect any incoming thermal radiation. If an object is warmer than its surroundings, the net energy flow will be from the warmer to colder areas until the temperatures are equal. Note that the incoming electromagnetic radiation to Earth’s surface is largely at visible and near infrared wavelengths; the outgoing far infrared radiation from the Earth’s surface is at longer, lower energy wavelengths outside the visible spectrum.

Question 58

How does water’s heat capacity compare to that of land’s and what does it mean?

Answer 58

Water has a much higher heat capacity than rock, dirt, or other materials that make up the land’s surface. This means that water is slow to absorb heat and slow to release it. In contrast, dry ground heats up more quickly and then cools more quickly.

Question 59

How does the humidity, color, and surface of a landmass determine how it absorbs energy?

Answer 59

land masses are made of many different materials which reflect and absorb energy in different ways. Rougher surfaces absorb more energy than smooth surfaces, and dark surfaces absorb more energy than light surfaces. Moist surface absorb heat differently from dry ones, with dry ones absorbing heat faster

Question 60

Why is grass, or an other plant, cooler to walk on during a hot day rather than asphalt?

Answer 60

Photosynthesis

Question 61

What is albedo?

Answer 61

Albedo is the proportion of electromagnetic energy that is reflected by a surface

Question 62

How is albedo measured?

Answer 62

Albedo is measured from zero to one, with 0 absorbing all the light and 1 reflecting it all back

Question 63

What is Earth’s average albedo?

Answer 63

0.3

Question 64

What is the albedo of the ice cover on Earth?

Answer 64

0.9

Question 65

What is the general albedo of areas covered in plants, such as forests or grasslands?

Answer 65

Areas of land covered in plants, such as forests or grasslands, tend to have fairly low albedo

Question 66

What is the general albedo of urban areas? Why are tehy hotter than surrounding rural areas?

Answer 66

The albedo of urban areas is also low, but they transform more solar energy into heat, creating the urban heat island effect. Cities tend to be a few degrees warmer than surrounding rural areas because of this

Question 67

True or False: Albedo has a notable affect on weather and climate

Answer 67

True

Question 68

How does the changing color of land over seasons influence Albedo?

Answer 68

Over much of the world’s land masses, the color of the land changes over the course of the year. This yearly variation in albedo is most pronounced in the boreal forests, which cover 12 percent of Earth’s land area and are dark in the summer and white in the winter. As albedo shifts with the seasons, the amount of incoming energy reflected or absorbed also shifts.

Question 69

Albedo Definition

Answer 69

The amount of light reflected by a surface

Question 70

How does Albedo differ based on latitude? When is Albedo at its highest?

Answer 70

In addition to varying over the year, the albedo of Earth’s surface is different at different latitudes. At the snow-and ice-covered poles, albedo is high. Near the equator, mostly covered by dark blue ocean, albedo is much lower. Earth’s overall albedo is highest when the land in the northern latitudes is largely covered in snow. There is another, smaller peak in albedo when Antarctic sea ice is at a maximum.

Question 71

What must occur for Earth’s overall temperature and climate to remain stable over time?

Answer 71

Energy input and output are different at different latitudes. In the tropics, more energy is absorbed than is radiated back. At the poles, more energy is radiated than absorbed. For Earth’s overall temperature and climate to be stable over time, these inputs and outputs must balance.

Question 72

How do different heating patterns of different land surface influence weather and climate? How does the presence of water influence weather and climate?

Answer 72

Different heating patterns of different land surfaces affect weather and climate patterns. Differences in surface heating lead to rising air over warmer regions and sinking air over cooler areas, driving wind patterns. This effect is pronounced for land next to large bodies of water. Over the course of a day the temperature of the water will stay fairly constant, due to water’s high heat capacity. In summer, the adjacent land will heat quickly during the day, warming the air above the surface. This air rises, drawing in a sea breeze which cools the land. At night the land cools rapidly as the water remains at the same temperature, and the effect is reversed.

Question 73

How is the climate of a landmass impacted by the presence of nearby water?

Answer 73

The climate for settlements along the edges of the oceans is mediated by the ocean’s ability to absorb and release large amounts of heat. A settlement along the coast will tend to have milder summers and winters, while a settlement hundreds of miles inland at the same latitude will likely have larger swings in temperature.

Question 74

How does human activity alter landscapes and climates?

Answer 74

When human activity alters the landscape, the amount of heat reflected and absorbed by the surface can change. Different plants reflect light in different way. For example, grassland has a higher albedo than forest. Replacing wilderness with farmland will alter the albedo of a region. When people build cities, this alters both the albedo of the land surface and the presence of water to absorb some of the heat. In the summer, cities can be several degrees hotter than the surrounding countryside and can also be drier. Farming and building cities directly alter the surface of the land. Albedo of the land surface can also change if humans alter other factors in the climate. When greenhouse gases are added to the atmosphere, more heat is retained. Ice has a very high albedo, reflecting most of the incident light. When snow spreads over the land in the early winter it raises the albedo, reflecting back more electromagnetic energy and absorbing less. When snow melts in the spring, the effect is reversed. As Earth’s climate warms, this effect is amplified—ice melts earlier and more widely, so more dark soil is exposed and exposed earlier in the year, so more energy is absorbed, and therefore the region is warmed further. In Earth’s distant past the reverse happened, with spreading ice reflecting more energy so that the planet cooled more, leading to more ice. Long ago, Earth’s surface may have completely frozen over during these extreme cycles.

Question 75

As settlements move further inland, away from water, what climatic and seasonal patterns should you expect?

Answer 75

As settlements move inland, away from water, expect higher summer highs, lower winter lows, and greater daily variation in the temperature

Question 76

How does water help regulate the temperature in adjacent lands and in the Earth?

Answer 76

A large body of water will soak up heat when it is warm and release it when it is cool. This modulating effect on local climate is seen over cycles of both the day and the year. On a longer and planet-wide scale, Earth’s oceans regulate the temperature of the planet as a whole. The oceans absorb much of the incident solar energy and later radiate that energy back into the atmosphere.

Question 77

Near infrared Definition

Answer 77

Wavelengths of electromagnetic energy just outside the visible light wavelengths

Question 78

How many times greater is water’s specific heat capacity compared to land’s? What does this mean? Where is most of Earth’s thermal energy stored?

Answer 78

Water’s specific heat capacity is about four times that of land, so a section of water can absorb far more energy than an equal area of land before its temperature significantly rises. Most thermal energy at Earth’s surface is stored in the oceans.

Question 79

Where does most solar energy flow into Earth’s surface?

Answer 79

Incident solar energy is strongest at the equator, where the sun’s rays are almost perpendicular to the surface. At mid-latitudes the sun’s rays are more glancing, and near the poles the light can travel parallel to the surface. Most solar energy therefore flows into Earth’s surface near the equator, and this region is mostly covered in water, which has a low albedo and is excellent at absorbing thermal energy. Some of this energy returns to the atmosphere through evaporation. It can also be transferred through conduction and convection when a warm ocean heats the cooler air above it.

Question 80

How is energy in the atmosphere transferred? How is energy transferred in the ocean?

Answer 80

In the tropics, more electromagnetic energy is absorbed than emitted. In the polar regions, more electromagnetic energy is emitted than absorbed. The pattern is energy in at the equator and out at the poles. In the atmosphere, this energy is transferred by wind as warm air rises and cool air sinks. In the ocean, the thermal energy is transferred in ocean currents. Warm water is carried in surface currents toward the poles, where it cools and sinks.

Question 81

Example: On a sheet of lined notebook paper, draw a circle several inches across. The circle represents Earth, and the spaces between adjacent lines represent equal amounts of incoming sunlight. Near the middle of your circle, which represents areas near the equator, the sunlight is concentrated on a small area. As you move away from the poles the amount of sunlight stays the same, but the area over which it spreads grows larger with latitude. The incoming sunlight per unit of surface area is much greater in the tropics than near the poles.

Answer 81

On a sheet of lined notebook paper, draw a circle several inches across. The circle represents Earth, and the spaces between adjacent lines represent equal amounts of incoming sunlight. Near the middle of your circle, which represents areas near the equator, the sunlight is concentrated on a small area. As you move away from the poles the amount of sunlight stays the same, but the area over which it spreads grows larger with latitude. The incoming sunlight per unit of surface area is much greater in the tropics than near the poles.

Question 82

What are the three layers of the ocean, and how do they compare in volume?

Answer 82

The ocean is divided into three layers: surface waters, the thermocline, and deep ocean. Most of the water is contained in the deep ocean, followed by the thermocline, followed by the surface waters.

Question 83

What are the characteristics of the first layer of the ocean, the surface waters?

Answer 83

Outside of the polar regions, sunlight provides a lot of thermal energy to this layer of water. Sea surface temperatures are just below freezing at the poles and around 29°C (85°F) at the equator. The surface layer is stirred by wind-driven waves and by tides. When the atmosphere is warmer than the surface water, heat is transferred to the ocean by conduction from the atmosphere, and vice versa when the atmosphere is cooler than the surface water.

Question 84

What are the characteristics of the second layer of the ocean, the thermocline?

Answer 84

The surface waters are defined by being well mixed and, in a given region, fairly uniform in temperature. Below about 400 m (1,312 ft.) in depth, temperature starts to decrease sharply with depth until around 1,000 m (3,281 ft.). At this point the temperature becomes almost uniform again, marking the top of the deep ocean. This middle layer is called the thermocline. Because the warmest layer is on the top of the ocean and colder water beneath, and warm water floats on colder water, the different layers do not undergo much vertical mixing.

Question 85

What are the characteristics of the last layer of the ocean, the deep ocean?

Answer 85

In the deep ocean the temperature is again almost uniform, 0°–4°C (32°–39°F). The deep ocean contains about 90 percent of all ocean water, and does not mix much with the other layers. What exchange there is occurs over very long time periods of hundreds or even thousands of years. Warming of surface waters now will affect the deep ocean for centuries.

Question 86

Therm (heat) + haline (salt) equals what?

Answer 86

Thermohaline

Question 87

What does thermohaline circulation describe? What factors affect the density of water?

Answer 87

Thermocline circulation describes the way oceanic water moves around the globe. Heat and salinity determine water density, and water density affects how Earth’s main ocean currents travel

Question 88

What temperature of water is denser? What salinity of water is denser?

Answer 88

Cold water is denser than warm water, and salt water is denser than fresh water. The denser the water, the more it sinks

Question 89

Why is water near the poles more dense?

Answer 89

Water at the poles is cold and salty, and therefore, dense. Sunlight does not hit the poles directly, which makes the water cold. As ice forms, it leaves the salt behind, making the surrounding water very salty

Question 90

What movement of water forms the global conveyor belt of water?

Answer 90

As the water around the poles gets colder and saltier, it sinks, causing less dense water to replace it. This movement forms the global conveyor belt of water

Question 91

How does the absorption habits of the oceans influence the climate and weather on Earth?

Answer 91

The ocean covers 70 percent of Earth’s surface. It exchanges heat, carbon dioxide, and moisture with the atmosphere. This exchange drives weather patterns and shapes the climate zones we see on land. Most of the rain that falls over land started as water in the ocean. When ocean water evaporates it increases the temperature and humidity of the surrounding air. At altitude, the water vapor condenses into clouds and is carried by the trade winds, in the atmospheric circulation driven by heat imbalances in the atmosphere.

Question 92

How does the ocean stabilize the climate and weather on Earth?

Answer 92

Just the top three meters of the ocean store more heat than the entire atmosphere. This huge reserve of thermal energy stabilizes Earth’s temperature over time. The ocean slowly warms in the summer, removing heat from the air above it, and cools in the winter, adding heat to the air above it.

Question 93

How do sea surface temperatures influence weather? What is El Niño?

Answer 93

Sea surface temperatures have a strong effect on weather. Hurricanes and typhoons draw energy from warm ocean waters. El Niño, a weather pattern that affects rainfall patterns across the globe, depends on a change in temperature of 2°–3°C (3.6°–5.4°F) over part of the equatorial Pacific. Strong winds that push surface water away from land allow cold water from the deep sea to well up, affecting the local climate.

Question 94

How do the ocean and atmosphere compare in their transfer of energy to the poles?

Answer 94

The ocean and atmosphere transfer roughly equal amounts of heat from the equator to the poles. Ocean currents are much slower than wind, so changes in the distribution of heat in the ocean occur much more slowly than in the atmosphere.

Question 95

What are the characteristics of surface currents?

Answer 95

Surface currents flow through all ocean basins in the top few hundred meters of water. Surface currents are caused by wind blowing horizontally across the water. Surface currents form gyres in each major ocean basin. In the Northern Hemisphere, the gyres flow clockwise, with warm water moving heat from the equator toward the North Pole. As the water moves north to higher latitudes, it cools. Cold water is returned to equatorial regions then it flows south from the North Pole to lower latitudes. The opposite occurs in ocean basins in the Southern Hemisphere

Question 96

Surface Current Definition

Answer 96

Ocean current caused by wind that moves horizontally near the surface

Question 97

Gyre Definition

Answer 97

System of currents in an ocean basin

Question 98

How do currents affect the temperature in certain regions? How does the Gulf Stream affect temperature in the United Kingdom?

Answer 98

When a current, such as the Gulf Stream in the Atlantic Ocean, brings warm water north, it affects the climate of certain regions. Temperatures in the winter in the United Kingdom are more moderate compared to temperatures at the same latitude in Canada

Question 99

How does the movement of cold water and warm water show a connection between the atmosphere and the ocean?

Answer 99

The ocean and the atmosphere are connected, as both wind and ocean currents move warm water toward the poles and cold water to the equator, which then affects the weather in those areas

Question 100

How does the warm water from the Gulf Stream impact the climate in Northern Europe?

Answer 100

The warm water from the Gulf Stream keeps the winters in Northern Europe mild (climatic impact)

Question 101

What are El Niño and La Niña?

Answer 101

El Niño and La Niña are the warm and cool phases of a recurring climate pattern across the tropical Pacific, which leads to variations in the ocean’s temperature, creating complex weather patterns all over the world—disruptions of temperature, precipitation, and winds. There are even more thunderstorms, or convection, resulting in another climatic impact

Question 102

How do warm water currents and cold water currents near the coast affects land?

Answer 102

Warm water currents that run along the coast usually lead to warmer temperatures on land. Cold water currents that run along the coast usually result in cooler air over land

Question 103

What are the characteristics of deep ocean currents? Why are they often referred to as the global ocean conveyor belt?

Answer 103

Deep currents flow in the deep ocean. They are caused by differences in density between water masses. Cold, salty, dense water sinks vertically near the poles and moves horizontally through the ocean, resurfacing in different areas. Like surface currents, deep currents move heat and water throughout the ocean. The circulation pattern of deep currents is often referred to as the global ocean conveyor belt

Question 104

Deep Current Definition

Answer 104

Ocean current caused by differences in density that moves vertically and horizontally

Question 105

What do scientists predict would happen in Northern Europe if the global conveyor belt were to stop?

Answer 105

If the global ocean conveyor belt were to stop, scientists predict that temperatures in Northern Europe could decrease by 5 to 10 degrees Celsius

Question 106

True or False: The global ocean conveyor belt moves cold subsurface currents from the North Atlantic Ocean to the North Pacific Ocean

Answer 106

True

Question 107

How and when does upwelling occur?

Answer 107

Sometimes cold water moves vertically from deeper areas of the ocean to the surface. Upwelling occurs when wind combined with another force pushes surface water away from the coast. Deeper water is pulled up to the surface to replace the water that has been pushed away

Question 108

What happens during normal years, outside of El Niño?

Answer 108

During normal years, winds move surface water on the eastern side of the Pacific Ocean to the west. This results in upwelling along the west coast of South America

Question 109

Upwelling Definition

Answer 109

Ocean current in which cold water moves up toward the surface from deeper areas

Question 110

What are the effects of a normal year and an El Niño year?

Answer 110

The cold water on the eastern side of the equatorial Pacific results in drier air and less rainfall compared to areas near Asia on the western side of the Pacific Ocean. During an El Niño year, the wind does not blow as strong and warm water remains at the surface along the east coast of South America. Upwelling does not occur, and weather patterns around the world can change. Increased rainfall on the coast of South America can cause flooding, and droughts are more common in Indonesia and Australia.

Question 111

How fast can hurricane winds get?

Answer 111

150 mph

Question 112

What do hurricane hunters do and measure?

Answer 112

While hurricanes are crossing the ocean, hurricane hunters take off in airplanes loaded with weather instruments. They fly several paths through the hurricane and directly through its center, or eye. The scientists use radar to scan the interior of the storm. They also drop instruments from the plane that measure air pressure, temperature, humidity, and winds as they fall through the storm clouds to the sea surface. The data allow meteorologists to determine the strength of winds, the amount of precipitation, and the track of the storm. When forecasters warn cities in the path of a hurricane or report on the strength of its winds, much of the thanks belongs to these daring scientists.

Question 113

What is air pressure and what forms it?

Answer 113

Air is invisible, but it is composed of tiny particles with mass and weight. Air particles are affected by Earth’s gravity, pulling them downward toward Earth’s surface. At each location on the planet’s surface or in the atmosphere, the column of air pressing down from above has a certain air pressure at that spot.

Question 114

Air pressure Definition

Answer 114

The weight of a column of air above a certain spot

Question 115

What do variations in air pressure signal? How is the air pressure like in a hurricane?

Answer 115

Variations in air pressure signal changes in the weather. The air pressure in the center of a storm such as a hurricane is extremely low. As the storm passes and the weather clears, the pressure increases.

Question 116

How does the temperature and density of air masses impact air pressure? What weather does low air pressure bring? What weather does high air pressure bring?

Answer 116

Temperature and humidity affect air density and therefore pressure. Colder air is denser than warmer air. Dry air is denser than air containing a lot of water vapor. Air pressure changes depending on whether air is rising or sinking. For example, rising air presses on Earth’s surface with less force, creating lower air pressure. Rising air is also associated with cloud formation and precipitation. Sinking air has higher air pressure and usually predicts more stability in the atmosphere and drier weather conditions.

Question 117

How does the Earth’s tilt affect air pressure? What creates wind?

Answer 117

Air pressure is not the same on every part of Earth’s surface. Because of Earth’s tilt and its curvature, the sun heats Earth’s surface unequally. For example, the trees of a tropical rainforest will absorb most of the solar energy that hits them, while most of the solar energy that strikes an ice-covered lake will be reflected. Differences in ground heating result in differences in air pressure. Air moves from areas of higher pressure to areas of lower pressure, like water flowing downhill. This air movement is wind. The greater the pressure difference, the stronger the wind.

Question 118

Wind Definition

Answer 118

The movement of air from higher to lower pressure

Question 119

How does air pressure form a sea breeze?

Answer 119

The unequal heating of land and sea can cause wind to blow from the sea toward the land on a hot summer afternoon. The sun heats up land more quickly than it heats up water, creating rising air and low pressure over land. Air moves from the higher-pressure area over the water toward the lower pressure area over land, forming a sea breeze.

Question 120

Why do hurricanes have strong winds, due to air pressure?

Answer 120

The winds of a hurricane are strong because there is an area of extremely low pressure at the center the storm. The low-pressure center pulls in air from higher-pressure areas around it, creating a swirling vortex of strong winds.

Question 121

What are source regions and what do they they determine in air masses?

Answer 121

Air masses are often more than 1000 miles wide and several miles thick. They form over source regions, which determine their characteristics. An air mass that forms over a cool, humid source region like the northern Atlantic Ocean, will be cool and humid. A source region such as the deserts of the southwestern United States, would produce air masses that are warm and dry.

Question 122

Source Region Definition

Answer 122

An area where an air mass forms

Question 123

Why are air masses important to weather?

Answer 123

Air masses are important because they dominate weather and weather changes. A warm, dry air mass brings fair weather and sunny skies. If a cool, humid air mass rolls in, the weather will change and could turn cool and gray.

Question 124

True or False: High pressure and low pressure can also indicate specific types of weather. Forecasters can make predictions about weather depending on whether a system with high pressure or low pressure is approaching an area.

Answer 124

True

Question 125

What are the different types of source regions?

Answer 125

Warm source regions are tropical (T), cool source regions are polar (P) or artic (A), source regions over water are maritime (m), while those over land are continental (c)

Question 126

True or False: Cold fronts and warm fronts are both associated with low air pressure because of unstable, rising air

Answer 126

True

Question 127

What is a cyclone?

Answer 127

A cyclone is a system of winds that rotate clockwise (in the Northern Hemisphere) around a low-pressure center

Question 128

What happens to air pressure as altitude increases?

Answer 128

Air pressure decreases

Question 129

What scientific tool is used to measure changes in air pressure?

Answer 129

A barometer

Question 130

What weather do low-pressure areas usually experience?

Answer 130

Low-pressure areas usually have clouds, wind, and precipitation

Question 131

What weather do high-pressure areas experience?

Answer 131

High-pressure areas have drier, warmer, and calmer weather

Question 132

How do Earth’s systems interact?

Answer 132

Earth’s systems—the atmosphere, the biosphere, the geosphere, and the hydrosphere— interact by exchanging energy and matter. The output of one system becomes the input of another. This exchange occurs continuously in numerous ways. Energy from the land and ocean warms the atmosphere. Evaporation of water carries energy into the atmosphere. Humans interact with the systems on Earth by using resources and making changes to Earth’s surface and atmosphere. These changes can alter the natural flow of energy in all of the Earth’s systems.

Question 133

True or False: Earth’s atmosphere takes in about the same amount of energy by evaporation and transpiration from Earth’s surface as it absorbs directly from incoming solar radiation.

Answer 133

True

Question 134

How can the interaction between two of Earth’s systems result in climatic changes, such as a large volcanic eruption?

Answer 134

The flow of energy and matter between systems produces changes in Earth’s climate. Some of these changes occur within a relatively short period of time. A large volcanic eruption, for example, results in the interaction of the geosphere and the atmosphere. The eruption releases large amounts of gases and dust into the atmosphere. Winds carry the particles around the globe where the gases reflect sunlight back into space and the dust cools Earth by blocking sunlight.

Question 135

How do ocean currents influence climate by the interaction of the hydrosphere and the atmosphere? What is El Niño?

Answer 135

Ocean currents affect climate by an interaction of the hydrosphere and the atmosphere. Both surface currents and deep ocean currents transfer heat to different areas. The warmer water produces warmer temperatures in a region and increases evaporation of surface water. An example of this effect is the El Niño cycle of changing the location of warm surface waters in the tropical regions of the Pacific Ocean. This warming alters the temperature and precipitation patterns in land areas on both sides of the Pacific.

Question 136

How have fossil fuels, an interaction between the biosphere and the atmosphere, affected Earth?

Answer 136

Some energy flowing into and out of Earth’s systems can cause climate changes over hundreds or thousands of years. For example, the increase in fossil fuel use by humans alters the composition of the atmosphere. These changes alter climate by increasing the retention of thermal energy in the atmosphere.

Question 137

Remember: Both natural events and human actions produce long-term changes in ocean currents. These changes have dramatic effects on climate by altering regional temperature and precipitation patterns.

Answer 137

Both natural events and human actions produce long-term changes in ocean currents. These changes have dramatic effects on climate by altering regional temperature and precipitation patterns.

Question 138

How does the solar cycle influence atmospheric conditions and climate?

Answer 138

The solar cycle causes atmospheric changes that alter Earth’s global winds and ocean currents. Climate effects include variations in storms, winds, and temperatures on Earth’s surface

Question 139

How much does the North American Plate move in a year?

Answer 139

2.3 cm (0.9 in)

Question 140

How much does the Pacific Plate move in a year?

Answer 140

7-11 cm (2.8-4.3 in)

Question 141

How do changes in the position and shape of land impact climate and weather?

Answer 141

The slow changes in positions and sizes of land masses on Earth surface dramatically alter ocean currents and weather patterns. Antarctica, for example, once had a mild climate and was covered by forests.

Question 142

How do the Himalayan Mountains impact the climate in the Indian Subcontinent?

Answer 142

By blocking cold air from the North

Question 143

Remember: When volcanoes erupt they erupt they produce sulfur dioxide, which turns into sulfate aerosols in the stratosphere. Sunlight reflects off these aerosols, leading to cooler temperatures (1-10 year change)

Answer 143

When volcanoes erupt they erupt they produce sulfur dioxide, which turns into sulfate aerosols in the stratosphere. Sunlight reflects off these aerosols, leading to cooler temperatures (1-10 year change)

Question 144

True or False: The solar cycle does not have a strong contribution to climate change

Answer 144

True

Question 145

True or False: as oxygen increased in the atmosphere, the more sunlight was reflected

Answer 145

True