Earth’s Processes: Climate and Weather (Unit 2) Flashcards
1
Q
What is the extent of the atmosphere and what is its purpose?
A
Earth’s atmosphere extends from the surface of the planet into outer space. It shields life on Earth from the harsh conditions of space
2
Q
Atmosphere Definition
A
The envelope of gases and small particles that surround Earth
3
Q
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?
A
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
4
Q
What are the characteristics of the first layer of the atmosphere, the troposphere?
A
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
5
Q
Troposphere Definition
A
The layer of the atmosphere closest to Earth’s surface
6
Q
In which layer does almost all weather, including clouds, occur? How does the speed of wind differ with altitude?
A
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
7
Q
What are the characteristics of the second layer of the atmosphere, the stratosphere?
A
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.
8
Q
Stratosphere Definition
A
The layer of the Earth’s atmosphere above the troposphere
9
Q
What kind of clouds can be formed in the stratosphere?
A
Wispy clouds made of ice and super cooled water can form in the stratosphere, which is very dry
10
Q
Why does the temperature in the stratosphere increase as altitude increases?
A
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.
11
Q
What are some forms of ionizing radiation? How do they interact with the atmosphere (absorption) and atoms?
A
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.
12
Q
What happens when atoms are ionized? Why does ionizing radiation pose a threat to living things?
A
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.
13
Q
What two characteristics do ionizing radiation have?
A
High frequency and low wavelength
14
Q
What are the characteristic of the third, middle layer of the atmosphere, the mesosphere?
A
Above the stratosphere is the mesosphere. As in the troposphere, temperature decreases with altitude, so there is vertical mixing of gases in this layer.
15
Q
Mesosphere Definition
A
Middle layer of the atmosphere
16
Q
What kind of clouds can form in the mesosphere?
A
Ice crystal clouds can form in the mesosphere
17
Q
Under what circumstances can clouds in the mesosphere form?
A
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.
18
Q
What are the characteristics of the fourth layer of the atmosphere, the thermosphere?
A
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.
19
Q
Thermosphere Definition
A
The hottest and most ionized layer of Earth’s atmosphere
20
Q
What are the characteristics of the last layer of the atmosphere, the exosphere?
A
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.
21
Q
Exosphere Definition
A
The outermost layer of Earth’s atmosphere
22
Q
Why would the thermosphere feel cool to exposed skin?
A
Because the air is so thin
23
Q
In which layer of the atmosphere do we live in?
A
The troposphere
24
Q
Three-fourths of the mass in the atmosphere is found in which layer?
A
The troposphere
25
Ozone is abundant in which layer of the atmosphere?
The stratosphere
26
Airplanes and weather balloons fly in which layer of the atmosphere?
The stratosphere
27
Where is the coldest part of the atmosphere?
At the top of the mesosphere
28
In which layer of the atmosphere do meteors burn?
In the mesosphere
29
Why is the mesosphere difficult to study?
The mesosphere is difficult to study since planes and weather balloons cannot reach it and spacecrafts and satellites orbit above it
30
Is the density of the thermosphere high or low?
The thermosphere has a very low density
31
True or False: the exosphere is very thin and some argue it is not apart of the atmosphere
True
32
What is the distribution of solar energy, along the electromagnetic spectrum, that reaches Earth?
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
33
True or False: Infrared radiation includes the thermal energy that can be felt as heat
True
34
What is the difference between electromagnetic waves and mechanical waves?
Electromagnetic waves can travel through empty space, while mechanical waves, such as sound waves , water waves, and seismic waves, can only travel through matter
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?
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.
36
What are examples of conditions that make up weather?
Precipitation, temperature, humidity cloudiness, and wind are examples of conditions that make up the weather in an area
37
Weather Definition
Atmospheric conditions at a specific time and place
38
How do changes in energy in different parts of the atmosphere form wind and storm systems?
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.
39
How is the sun a source of energy for tornadoes and hurricanes?
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.
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.
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.
41
What are the different types of fronts?
Stationary front, occluded front, cold front, and warm front
42
What are the characteristics of a tornado?
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).
43
What are the characteristics of a hurricane?
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.
44
Air mass Definition
A large body of air with similar temperature and humidity
45
Front Definition
The boundary between air masses
46
What does climate consist of?
Climate consists of averages, such as average yearly temperature and average monthly precipitation in an area.
47
How does the Earth’s tilt and rotation influence climate?
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.
48
Climate Definition
A pattern of atmospheric conditions over a long period of time
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.
True
50
What is albedo? What is Earth’s average albedo?
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.
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.
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.
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.
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.
53
How do land and water differ in their ways of absorbing and reflecting light?
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.
54
Opaque Definition
Absorbing or reflecting all of the incident electromagnetic energy
55
How does absorbed electromagnetic energy produce heat in surfaces? How does heat transfer between the Earth’s surface and atmosphere?
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.
56
Why does air just above a hot surface sometimes seem to shimmer?
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.
57
What are the three ways in which electromagnetic radiation flows out from the land and into the atmosphere?
— 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.
58
How does water’s heat capacity compare to that of land’s and what does it mean?
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.
59
How does the humidity, color, and surface of a landmass determine how it absorbs energy?
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
60
Why is grass, or an other plant, cooler to walk on during a hot day rather than asphalt?
Photosynthesis
61
What is albedo?
Albedo is the proportion of electromagnetic energy that is reflected by a surface
62
How is albedo measured?
Albedo is measured from zero to one, with 0 absorbing all the light and 1 reflecting it all back
63
What is Earth’s average albedo?
0.3
64
What is the albedo of the ice cover on Earth?
0.9
65
What is the general albedo of areas covered in plants, such as forests or grasslands?
Areas of land covered in plants, such as forests or grasslands, tend to have fairly low albedo
66
What is the general albedo of urban areas? Why are tehy hotter than surrounding rural areas?
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
67
True or False: Albedo has a notable affect on weather and climate
True
68
How does the changing color of land over seasons influence Albedo?
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.
69
Albedo Definition
The amount of light reflected by a surface
70
How does Albedo differ based on latitude? When is Albedo at its highest?
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.
71
What must occur for Earth’s overall temperature and climate to remain stable over time?
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.
72
How do different heating patterns of different land surface influence weather and climate? How does the presence of water influence weather and climate?
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.
73
How is the climate of a landmass impacted by the presence of nearby water?
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.
74
How does human activity alter landscapes and climates?
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.
75
As settlements move further inland, away from water, what climatic and seasonal patterns should you expect?
As settlements move inland, away from water, expect higher summer highs, lower winter lows, and greater daily variation in the temperature
76
How does water help regulate the temperature in adjacent lands and in the Earth?
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.
77
Near infrared Definition
Wavelengths of electromagnetic energy just outside the visible light wavelengths
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?
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.
79
Where does most solar energy flow into Earth’s surface?
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.
80
How is energy in the atmosphere transferred? How is energy transferred in the ocean?
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.
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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.
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.
82
What are the three layers of the ocean, and how do they compare in volume?
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.
83
What are the characteristics of the first layer of the ocean, the surface waters?
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.
84
What are the characteristics of the second layer of the ocean, the thermocline?
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.
85
What are the characteristics of the last layer of the ocean, the deep ocean?
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.
86
Therm (heat) + haline (salt) equals what?
Thermohaline
87
What does thermohaline circulation describe? What factors affect the density of water?
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
88
What temperature of water is denser? What salinity of water is denser?
Cold water is denser than warm water, and salt water is denser than fresh water. The denser the water, the more it sinks
89
Why is water near the poles more dense?
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
90
What movement of water forms the global conveyor belt of water?
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
91
How does the absorption habits of the oceans influence the climate and weather on Earth?
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.
92
How does the ocean stabilize the climate and weather on Earth?
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.
93
How do sea surface temperatures influence weather? What is El Niño?
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.
94
How do the ocean and atmosphere compare in their transfer of energy to the poles?
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.
95
What are the characteristics of surface currents?
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
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Surface Current Definition
Ocean current caused by wind that moves horizontally near the surface
97
Gyre Definition
System of currents in an ocean basin
98
How do currents affect the temperature in certain regions? How does the Gulf Stream affect temperature in the United Kingdom?
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
99
How does the movement of cold water and warm water show a connection between the atmosphere and the ocean?
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
100
How does the warm water from the Gulf Stream impact the climate in Northern Europe?
The warm water from the Gulf Stream keeps the winters in Northern Europe mild (climatic impact)
101
What are El Niño and La Niña?
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
102
How do warm water currents and cold water currents near the coast affects land?
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
103
What are the characteristics of deep ocean currents? Why are they often referred to as the global ocean conveyor belt?
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
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Deep Current Definition
Ocean current caused by differences in density that moves vertically and horizontally
105
What do scientists predict would happen in Northern Europe if the global conveyor belt were to stop?
If the global ocean conveyor belt were to stop, scientists predict that temperatures in Northern Europe could decrease by 5 to 10 degrees Celsius
106
True or False: The global ocean conveyor belt moves cold subsurface currents from the North Atlantic Ocean to the North Pacific Ocean
True
107
How and when does upwelling occur?
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
108
What happens during normal years, outside of El Niño?
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
109
Upwelling Definition
Ocean current in which cold water moves up toward the surface from deeper areas
110
What are the effects of a normal year and an El Niño year?
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.
111
How fast can hurricane winds get?
150 mph
112
What do hurricane hunters do and measure?
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.
113
What is air pressure and what forms it?
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.
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Air pressure Definition
The weight of a column of air above a certain spot
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What do variations in air pressure signal? How is the air pressure like in a hurricane?
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.
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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?
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.
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How does the Earth’s tilt affect air pressure? What creates wind?
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.
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Wind Definition
The movement of air from higher to lower pressure
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How does air pressure form a sea breeze?
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.
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Why do hurricanes have strong winds, due to air pressure?
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.
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What are source regions and what do they they determine in air masses?
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.
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Source Region Definition
An area where an air mass forms
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Why are air masses important to weather?
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.
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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.
True
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What are the different types of source regions?
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)
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True or False: Cold fronts and warm fronts are both associated with low air pressure because of unstable, rising air
True
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What is a cyclone?
A cyclone is a system of winds that rotate clockwise (in the Northern Hemisphere) around a low-pressure center
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What happens to air pressure as altitude increases?
Air pressure decreases
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What scientific tool is used to measure changes in air pressure?
A barometer
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What weather do low-pressure areas usually experience?
Low-pressure areas usually have clouds, wind, and precipitation
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What weather do high-pressure areas experience?
High-pressure areas have drier, warmer, and calmer weather
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How do Earth’s systems interact?
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.
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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.
True
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How can the interaction between two of Earth’s systems result in climatic changes, such as a large volcanic eruption?
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.
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How do ocean currents influence climate by the interaction of the hydrosphere and the atmosphere? What is El Niño?
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.
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How have fossil fuels, an interaction between the biosphere and the atmosphere, affected Earth?
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.
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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.
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.
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How does the solar cycle influence atmospheric conditions and climate?
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
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How much does the North American Plate move in a year?
2.3 cm (0.9 in)
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How much does the Pacific Plate move in a year?
7-11 cm (2.8-4.3 in)
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How do changes in the position and shape of land impact climate and weather?
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.
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How do the Himalayan Mountains impact the climate in the Indian Subcontinent?
By blocking cold air from the North
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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)
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)
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True or False: The solar cycle does not have a strong contribution to climate change
True
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True or False: as oxygen increased in the atmosphere, the more sunlight was reflected
True
