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6th Grade
Weather & Climate and Natural Hazards
2015-10-15 www.njctl.org
Slide 3 / 161 Table of Contents: Weather and Climate
Click on the topic to go to that section
· Sunlight and the Atmosphere · Circulation · Geography · Weather Prediction · Natural Disasters
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Sunlight and the Atmosphere
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Slide 5 / 161 Review: Weather vs Climate
In earlier grades, we learned that weather and climate differ from each other. Can you recall what the difference is between weather and climate? Click below to see the answer. · Weather is the current conditions of a location. · Climate is the average weather for a location. What is the weather and climate of your location?
Slide 6 / 161 Weather and Climate
Many factors influence weather and climate. Create a list at your table of some things you know can affect weather.
SLIDE 2 Slide 7 / 161 Weather and Climate
How many of these factors did you come up with? Sunlight Oceans Atmosphere Wind Ice Landforms Living Things
Slide 8 / 161 Climate
In what climate do you live?
Click here to watch a video about climate and weather.
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1 The annual average temperature of the tundra is -28 degrees Celsius. This refers to the tundra's ___. A weather B climate
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2 Today's forecast includes afternoon thunderstorms, but by tomorrow, it will be mostly sunny. This is an example of ___. A weather B climate
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3 Which of the following factors affects weather and climate? (Choose all that apply.) A sunlight B landforms C oceans D living things
Slide 12 / 161 Energy Review
Remember that energy is neither created nor destroyed. It simply changes form. Weather and climate are fueled by changes in energy. What do you think is the primary source of energy for weather and climate? Click in the box to check your answer.
Sunshine
SLIDE 3 Slide 13 / 161 Sunlight
The sun transfers heat to Earth's surface via electromagnetic waves. Electromagnetic waves is transferred into thermal energy (heat) when it strikes land and water bodies.
Slide 14 / 161 Solar Radiation
Electromagnetic waves, or solar radiation, from the sun travel to Earth. Some of this energy is reflected back into space. The remaining energy is absorbed by the Earth.
Source: NASA.gov
How would Earth feel without solar radiation?
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The electromagnetic radiation that reaches Earth's surface is
- absorbed. As the Earth heats up, it emits some of this heat as
infrared radiation. Part of the infrared radiation travels into space while the other part is trapped by Earth's atmosphere.
Infrared Radiation
The gases in Earth's atmosphere trap infrared radiation emitted by
- Earth. This helps Earth to
remain warm.
Slide 16 / 161 Atmosphere
To understand this process, think about a winter day. Is it warmer
- n a cloudy day or on a clear day?
A cloudy day is warmer than a clear day because the clouds prevent heat from escaping. versus
Slide 17 / 161 The Greenhouse Effect
The same is true about our atmosphere. The molecules in the atmosphere prevent all of Earth's heat from escaping into space. This is called the greenhouse effect. Gases in Earth's atmosphere are called greenhouse gases.
Slide 18 / 161 The Greenhouse Effect
What would happen if there were no greenhouse gases in the atmosphere? How would Earth feel? How about if Earth accumulated too many greenhouse gases? If there were no greenhouse gases, none of the infrared radiation would be retained. Earth would cool down. If there are too many greenhouse gases, too much infrared radiation would be retained. Earth would heat up.
SLIDE 4 Slide 19 / 161 Global Warming
Earth is currently heating up, due to an increase in greenhouse gases in the atmosphere. This phenomenon is called global warming. Global warming is a popular topic. What do you know about it? Write your thoughts below.
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Human activities, such as the burning of fossil fuels, releases additional greenhouse gases into the atmosphere. This causes more infrared radiation to be retained, leading to an increase in Earth's temperature.
Global Warming Slide 21 / 161
Carbon dioxide is a greenhouse gas. Look at this graph. What does it tell us about carbon dioxide? How does this impact Earth's temperature?
Global Warming
Click here to watch a video about the greenhouse effect.
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4 Solar radiation from the sun is also known as ___ radiation. A electromagnetic B hydrothermal C infrared D thermal
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5 All of the electromagnetic radiation from the sun is absorbed by Earth. True False
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6 As Earth heats up, it emits ___ radiation. A thermal B electromagnetic C infrared D solar
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7 What enables Earth to retain infrared radiation in
A solar gases B the lack of gases in the atmosphere C gravity D gases in the atmosphere
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8 An accumulation of too many greenhouse gases has led to global warming. True False
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Do all areas of Earth receive the same amounts of the sun's energy? Click the blue box to check your answer. How can you explain this? Discuss with a partner or as a class and write your ideas below. No
Sunlight Distribution Slide 28 / 161 Direct & Indirect Sunlight
Different areas of the planet receive different amounts of sunlight. At the equator, the sun's energy hits the Earth directly (direct sunlight). As you move away from the equator, the sun's energy hits the Earth at an angle (indirect sunlight). How do you think this affects the climate of an area?
Direct sunlight Indirect sunlight Indirect sunlight
Slide 29 / 161 Earth's Tilt
The amount of sunlight an area receives also depends on the time
The Earth is tilted on its axis as it rotates around the sun. This means that some areas are tilted towards the sun for part of the year and tilted away from the sun for part of the year. We call this annual change in thermal energy the seasons.
Slide 30 / 161 Earth's Tilt
Watch how the location of the red dot changes in relation to the sun's energy as the Earth orbits the sun. Based on the angle of sunlight, which picture shows summer and which picture shows winter for this location? Click in the boxes to check your answers. Winter Summer
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Polar Polar
Temperate Temperate Tropical Tropical 90 90 66 66 23 23 These zones are identified by horizontal lines called latitude. Each latitude zone has a specific climate.
Latitude
Due to different angles of sunlight, the Earth has 3 major climate zones: polar, tropical and temperate.
Slide 32 / 161 Tropical Latitudes
Tropical latitudes receive direct sunlight year round and are very
- warm. They do not experience much temperature change
throughout the year.
Slide 33 / 161 Polar Latitudes
Polar latitudes receive indirect sunlight year round and are very
- cold. They do not experience much temperature change
throughout the year.
Slide 34 / 161 Temperate Latitudes
Temperate latitudes receive direct sunlight for part of the year and indirect sunlight for part of the year. They experience four distinct seasons.
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9 Indirect sunlight transfers more heat than direct sunlight. True False
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10 What latitude receives the most direct sunlight throughout the year? A Polar B Temperate C Tropical
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11 Earth's tilt results in areas receiving different amounts of solar radiation throughout the year. True False
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Circulation
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Slide 39 / 161 Temperature and Circulation Demo
Temperature plays a key role in the density of objects. This affects how air and water circulate. This demonstration will look at how hot and cold water behave differently and what effect that has on circulation.
Slide 40 / 161 Density
In cool air or water, molecules are packed closely together. In warm air or water, molecules are spread farther apart. Which is less dense? Click in the box to check your answer. Warm air or water is less dense. Cool air or water Warm air or water
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We now know that cool, more dense fluid sinks while... warm, less dense fluid rises. How does this relate to air masses?
Density
Warm Air Cool Air
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Cool air is more dense than warm air. This means that warm air will rise above cool air. When different air masses move, we feel this as wind.
Wind
SLIDE 8 Slide 43 / 161 Air Circulation
The combinations of air masses creates circulation around the Earth. Look at the image. Can you explain what is happening at the equator and at the poles? Click to the next slide to find
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Warm air at the equator is less dense, so it rises. Meanwhile, cold air at the poles is more dense, so it sinks. This process creates circulation as the air masses move to fill in the empty spaces.
Air Circulation
Circulation is driven by changes in the density of air masses. And remember... What is responsible for the different densities? Unequal heating of the Earth by the sun
Slide 45 / 161 Air Circulation
Air masses transfer heat. Warm air that travels away from the equator is able to warm cooler areas. Cooler air that travels away from the poles is able to cool warmer areas. This moderates climate across the Earth. Describe how conditions on Earth would be different if there were no air circulation. Write your thoughts below.
Slide 46 / 161 Prevailing Winds
Prevailing winds are winds that constantly travel from one direction. Prevailing winds are the result of the constant circulation of air
- masses. What type of prevailing wind exists where you live?
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Air currents not only carry heat, they also carry moisture around Earth. As air becomes warm, it can hold more water vapor because it is less dense. As air becomes cold, it can hold less water vapor because it is more dense.
Air Circulation
Would warm or cold prevailing winds carry more moisture? Explain why.
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In addition, moisture content in prevailing winds is affected by
- location. Winds traveling over land are dry while winds traveling over
water are moist. Would air reaching western Europe be dry or wet?
Prevailing Winds
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The desert in Africa (red dot) and the rainforest ecosystem in Central America (black dot) are located at similar latitudes. Although they are both hot, the desert is very dry while the rainforest is very wet. Can you explain this using prevailing winds?
Prevailing Winds Slide 50 / 161
12 Warm air is ___ dense than cool air. A more B less
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13 Cool air sinks and warm air rises. True False
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14 What do air masses transfer from one area to another? A heat B moisture C solar radiation D both A and B
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15 Prevailing winds travel in one direction for part of the year and another direction for part of the year. True False
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Heat capacity is a measurement of how much energy is required to increase the temperature of a substance. A substance with a high heat capacity can hold a lot of heat before its temperature increases.
Heat Capacity
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Another way to think about heat capacity is to say that a substance with a high heat capacity will heat up slower than a substance with low heat capacity.
Heat Capacity
Aluminum Heat capacity: 0.900 Copper Heat capacity: 0.385 Which will heat up faster: copper or aluminum?
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Do you think land or water has a higher heat capacity? In other words, which will take longer to heat up?
Heat Capacity Demo Slide 57 / 161
Water has a much higher heat capacity than land. It warms up much slower than land.
Heat Capacity of Water
Think about the beach on a hot, summer day. You often have to run across the sand so that you don't burn your feet. The ocean, however, feels much cooler. Which has a higher heat capacity: water or land? Click below to check your answer.
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16 Heat capacity is the amount of energy needed to ___ the temperature of a substance. A raise B lower
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17 A substance with a high heat capacity warms up faster than a substance with a low heat capacity. True False
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18 Which has a higher heat capacity? A water B land
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19 Iron has a heat capacity of 0.48. Lead has a heat capacity of 0.13. If a sample of each receives direct sunlight for 30 minutes, which will have a higher increase in temperature? A iron B lead
Slide 62 / 161 Heat Capacity of Water
Water's high heat capacity allows it to store a large amount of thermal energy (heat) from the sun. The oceans absorb and store this energy. The upper 10 feet of the ocean holds as much heat as the entire atmosphere!
Slide 63 / 161 Oceans
Over 70% of Earth's surface is water. The oceans absorb and maintain energy. This helps to regulate our weather. Think about coastal cities and inland cities. Where is it warmer in the winter?
Slide 64 / 161 Oceans
The ocean has a steady temperature despite the seasons. Oceans absorb heat in the summer from the sun and release it very slowly during the winter. This helps to moderate temperature. People who live in costal regions experience warmer winters and cooler summers than inland regions.
Slide 65 / 161 Oceans
Oceans also transport energy around the world via circulation. Think back to how air circulates. How do you think ocean circulation works? Write your thoughts below.
Slide 66 / 161 Ocean Circulation Simulation
Observe how uneven heating causes the movement of water currents in this lab.
SLIDE 12 Slide 67 / 161 Oceanic Circulation
In surface waters, ocean currents move as a result of wind. In deeper water, oceanic circulation works because of differences in density, just like air circulation. Also similar to air circulation, ocean currents carry heat and moisture to other areas of the world as they travel. Heat is released into the atmosphere as the ocean currents travel.
Slide 68 / 161 Oceanic Circulation
Look at the Gulf Stream. It originates at the tip of Florida. Even though it picks up heat off the coast of North America, what area
- f Earth does the Gulf Stream warm?
Slide 69 / 161 Oceanic Circulation
Here is another depiction of the Gulf Stream. Notice how it carries heat northward. The climate of northern and western Europe would be much colder were it not for the heat transported by the Gulf Stream.
Slide 70 / 161 Oceans Affect Climate
Oceanic circulation moderates the climates on Earth. Remember that the sun heats the Earth unequally. The difference between the equator and the poles would be much more drastic were it not for
Without this circulation, Earth would be uninhabitable.
Click here to watch a video of ocean currents taken from outer space.
Slide 71 / 161 Oceans Affect Weather
Oceans also affect weather. Can you think of how? Discuss as a class and then click in the box to see the answer. (Hint: Think about the water cycle...) Evaporation from the
the water cycle. As the water molecules cool, they form clouds and weather
- systems. Almost all of the
moisture in the atmosphere
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20 Coastal cities are cooler in the summer than inland cities. True False
SLIDE 13
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21 Warm water will ___ cool water. A sink below B rise above
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22 What drives deep ocean currents? A wind speed B thunderstorms C density D wind direction
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23 Without oceanic circulation, the polar regions would be ___ than they are now. A colder B warmer
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24 Oceanic circulation affects climate but not weather. True False
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Geography
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Weather and climate are driven by the input of solar radiation and the circulation of that energy via air and water. Local and regional geography also plays a part in climate and weather. Think about where you live. What natural features are located nearby (mountains, oceans, lakes, etc.)? How might these affect your local climate and weather? Write your thoughts below:
Geography Affects Weather & Climate
SLIDE 14 Slide 79 / 161 Altitude
In many places, when we look at mountains in the distance, the peaks are covered in snow. From where we are standing, there is often no snow or it may be quite hot. What does this tell us about height above the Earth and temperature?
Slide 80 / 161 Altitude
You can consider the altitude of an object to be like your height. Your height is measured from the bottom of your feet to the top of your head. Altitude is the distance from a point
its point in the atmosphere.
Altitude
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As altitude increases, temperature decreases.
Altitude
Mount Everest peaks at 8,848 meters above sea level. At the base camp, where climbers prepare to make the ascent, the altitude is 5,400 meters above sea level. Click in the boxes to see the average temperatures of both locations in July.
Slide 82 / 161 Landforms
Landforms are natural physical features found on Earth's landscape. They affect weather and climate patterns in different ways. This is a picture of Bryce Canyon in Utah. What differences do you notice in the landscape? How might weather/climate vary in different parts of the canyon?
Slide 83 / 161 Case Study: Sierra Nevada
The Sierra Nevada is a mountain range that runs for 400 miles north-south and about 70 miles east-west in California. The climate on the east side of the mountains is vastly different from that on the west side of the mountains. Why do you think this happens?
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Redwood forests thrive to the west
Death Valley, the hottest and driest place in the U.S. exists to the east of the mountains. What hypothesis can you form about the effect of mountains on weather and climate? Write it in the box below.
Case Study: Sierra Nevada
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Let's test your hypothesis by looking at some data. Below is a chart that shows the average annual rainfall for four cities located around the Sierra Nevada.
Reno Paradise Death Valley Fresno
Revisit your hypothesis from the previous slide. Do you need to make any changes to it? City Annual Precipitation Paradise Reno Death Valley Fresno 58.11 in 7.39 in 12.83 in 2.4 in
Case Study: Sierra Nevada Slide 86 / 161
Based on the data, what can you conclude about climate on different sides of mountains? Write your thoughts in the green box and then click in the blue box to check your answer. One side of a mountain is often very wet while the other side is very dry.
Case Study: Sierra Nevada Slide 87 / 161 Landforms : Mountains
As warm, moist air encounters the mountain, it is forced to rise, where it cools. As it cools, it condenses and releases moisture. As air passes
mountain, it has lost all of its
becomes dry and
called a rain shadow.
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25 As altitude increases, temperature ___. A increases B decreases
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26 Suppose that a mountain range is located so that prevailing winds blow east to west across the
- mountains. Which side of the mountain range would
you expect to find a hot, dry climate? A east B west
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27 As air rises up a mountain, it condenses and creates precipitation. True False
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Suppose that there is a blizzard during the night. When you go
- utside in the morning, the skies are clear and the sun is shining
- bright. Everything is covered in snow and ice.
How do your eyes feel when looking at the surroundings? Do you wish you were wearing sunglasses? Keep this in mind as we move on to our next topic: glaciers.
Landforms: Glaciers Slide 92 / 161 Landforms: Glaciers
A glacier is a huge chunk of ice. When large amounts of snow build up, it turns into ice and forms layers. Glaciers are formed when more snow falls in the winter than evaporates in the summer.
Slide 93 / 161 Landforms: Glaciers
Glaciers cover about 10% of the land on Earth. They store about 75% of the freshwater available on Earth. What effect do you think glaciers have on climate and weather?
Slide 94 / 161 Landforms: Glaciers
When the sun's energy hits a glacier, it is reflected back into the atmosphere or space. How would this affect the local climate? Click in the box to check your answer. Glaciers keep an area cooler because they do not absorb solar radiation.
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28 If there were no glaciers, Earth would be much ___ than it currently is. A warmer B cooler
Slide 96 / 161 Landforms: Hills and Valleys
Hills and valleys create wind patterns due to differential heating. During the day, hilltops heat up faster than valleys. At night, hilltops cool down faster than valleys. Think about what you know about the density of air masses. How would this affect wind patterns around hilltops and valleys?
SLIDE 17 Slide 97 / 161 Landforms: Hills and Valleys
During the day, the land heats up and transfers this energy to the surrounding air. The air becomes less dense and rises upwards. So...during the day, wind flows upwards from a valley to a hilltop.
Slide 98 / 161 Landforms: Hills and Valleys
At night, the air at the top of the hill cools faster than in the valley. This denser air will sink down towards the valley. So...at night, wind flows down from a hilltop into a valley.
Slide 99 / 161 Land & Sea
This same logic applies for coastal areas. Think about land that is next to bodies of water. Which heats up faster during the day? What type of breeze would occur during the day? Draw in your ideas in the picture below.
Slide 100 / 161 Seabreeze
Seabreeze
The land will heat up faster than the ocean. This less dense air will
- rise. The empty space left behind will be replaced by air over the
- cean, creating a seabreeze.
Slide 101 / 161 Land & Sea
Now, let's think about the night. Which area will cool down faster? What type of breeze would occur during the night? Draw in your ideas in the picture below.
Slide 102 / 161 Land Breeze
The land will cool off faster than the ocean. The less dense air over the ocean will rise. The empty space left behind will be replaced by air over the land, creating a land breeze.
Land breeze
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29 During the day, wind flows from a hilltop down into a valley. True False
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30 During the day, a seabreeze flows from the ocean
- nto the land because ___.
A the ocean heats up faster than the land. B the ocean cools off faster than the land. C humidity is higher over the ocean. D the land heats up faster than the ocean.
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31 At night, the air over the land is ___ dense than the air over the ocean. A more B less
Slide 106 / 161 Living Things
Living things are also capable of affecting weather and climate. Think back to our discussion about greenhouse gases. Can you think of a way that humans are affecting global climate?
Slide 107 / 161 Global Warming
As humans increase their output of greenhouse gases, the atmosphere traps additional heat on Earth. This makes the global temperature increase and we experience global warming. What types of activities increase greenhouse gases? Write your ideas below:
Slide 108 / 161 Global Warming
This chart shows the sources of greenhouse gases by human use while the table describes the activities associated with each. How many of these did you think of? Greenhouse Gas Activity Carbon Dioxide Fossil fuels, deforestation, decay of biomass Methane Agricultural activities, waste management Nitrous Oxide Agricultural activities (fertilizer) Flourinated Gases (F-gases) Industrial processes
SLIDE 19 Slide 109 / 161 Global Warming
The effects of global warming are far reaching.
Slide 110 / 161 Global Warming
Two effects of global warming are increased temperature over
- ceans and a decrease in glaciers. Think about what you know
about weather patterns. What would be a result of these two events happening? Discuss as a class and then click in the box to check your answer. The warm ocean air and the cold polar air drives circulation and distributes solar radiation. If the glaciers melt, polar areas will increase in temperature along with the oceans. There will not be a large difference in the density of air masses. Circulation around the Earth could stop!
Slide 111 / 161 Deforestation
Another way humans affect the environment is through
- deforestation. How would removing all plants from Earth affect
climate and weather? Discuss as a class and click in the forest to check your answer. Plants take in carbon dioxide and release oxygen. If plants are removed, the carbon dioxide in the atmosphere will increase. This will lead to further global warming.
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32 Living things do not affect weather and climate. True False
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33 Which activities increase greenhouse gases in the atmosphere? (Choose all that apply.) A burning fossil fuels B reforestation C industrial processes D agricultural activities
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34 Which of the following is not an effect of global warming? A Glaciers increase. B Sea temperatures increase. C Sea ice decreases. D Sea levels increase.
SLIDE 20 Slide 115 / 161 Test Your Knowledge
Use all the knowledge you have learned to compare the climate in each pair of locations. Click in the box at the bottom to check your answer.
Daytona Beach, FL Cape Cod, MA
Daytona Beach is located closer to the equator than Cape Cod. It will receive more direct sunlight and will have a warmer climate.
Slide 116 / 161 Test Your Knowledge
Outer Banks, NC The Midwest
The Outer Banks will have cooler summers and warmer winters than the midwest. The ocean absorbs heat in the summer and releases heat into the atmosphere in the winter. The temperatures in the midwest will be more extreme since land heats up and cools
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Antofagasta, Chile Oran, Argentina P r e v a i l i n g w i n d s
Test Your Knowledge
Prevailing winds blow from east to west across the Andes Mountains
- n the west coast of South America.
Antofagasta will have a drier climate than Oran. As the winds travel up the east side
- f the Andes, the air will cool
and condense as
descend the west side of the Andes, the air will be very dry.
Slide 118 / 161 Test Your Knowledge
Peak Base
- Mt. McKinley is the highest peak in North American, with an elevation
- f 6,168 meters.
As altitude increases, temperature decreases. It will be much colder at the peak than at the base.
Slide 119 / 161 Climate Trends Lab
We already know that greenhouse gases in the atmosphere trap heat
- n Earth. Can you design an experiment that verifies this information?
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Weather Prediction
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SLIDE 21 Slide 121 / 161 Weather Prediction
As you now know, there are several different factors that affect
- weather. Weather is dynamic (always changing). This makes
weather prediction difficult.
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Meteorologists study the data and make the best forecasts possible.
Weather Prediction
Because they never know exactly what will happen, they use probability forecasting. "There is a 60% chance of an afternoon thunderstorm."
Slide 123 / 161 Pressure Systems
Meteorologists study pressure systems and fronts to predict weather. A high pressure system is composed of cool air. Do you think a high pressure system is wet or dry? Since cool air is dense, it cannot hold much moisture. High pressure systems are dry. High pressure systems are characterized by cooler temperatures, clear skies and fair weather.
Slide 124 / 161 Pressure Systems
A low pressure system is composed of warm air. Do you think a low pressure system is wet or dry? Since warm air is less dense, it can hold a lot of moisture. Low pressure systems are wet. Low pressure systems are characterized by warmer temperatures, storms and sometimes strong winds.
Slide 125 / 161 Weather Prediction
Check your knowledge. Click each box to see the correct information. Pressure System Characteristics Conditions Symbol on map High Cool, dry air Fair weather and light winds Low Warm, moist air Storms and strong winds
Slide 126 / 161 Pressure Systems
Can you locate one low pressure system and one high pressure system on this map?
SLIDE 22 Slide 127 / 161 Warm Fronts
A front is a boundary between cold and warm air. It is where warm air and cold air collide. A warm front occurs when warm air overtakes cold air. When this happens, the warm, less dense air rises above the cold, more dense air. As the warm air cools, it condenses and causes precipitation.
Slide 128 / 161 Cold Fronts
A cold front occurs when cold air overtakes warm air. When this happens, the cold, more dense air forces the warm, less dense air to quickly rise. This usually causes strong thunderstorms at the front boundary. After the boundary passes, a cold front usually brings clear skies and fair weather.
Slide 129 / 161 Weather Fronts
Front What is it? Conditions Symbol on map Cold Cold air replaces warm air. Storms replaced by lower temperatures and high pressure. Warm Warm air replaces cold air. Precipitation replaced by increased temperatures and low pressure. Check your knowledge. Click each box to see the correct information.
Slide 130 / 161 Weather Fronts
What types
you see on this map?
Click here to watch a video about weather fronts.
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35 Meteorologists use _____ forecasting to predict the weather. A pictorial B symbolic C probability
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36 Low pressure usually brings fair weather. True False
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37 High pressure contains _____ air. A cool, dry B cool, moist C warm, dry D warm, moist
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38 A front is a boundary between two air masses. True False
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39 A cold front brings rain and ___ pressure. A low B high
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Do you think you can predict the weather based on what you have learned in class?
Weather Prediction Activity Slide 137 / 161
Natural Disasters
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Slide 138 / 161 What is a natural disaster?
What images or terms come to mind when you hear the phrase "natural disaster"? Write your ideas below:
SLIDE 24 Slide 139 / 161 What is a natural disaster?
What is a natural disaster? Discuss as a group and decide upon a definition together. Write it below in the box.
Click here to watch some video clips from 2013 natural disasters.
Slide 140 / 161 Natural Disasters
A natural disaster is a catastrophic event that occurs as a result of natural processes.
Slide 141 / 161 Natural Disasters
There are numerous types of natural disasters. Scientists use data and information from previous occurrences to try to predict future events. Based on what you know about weather forecasting, do you think natural disasters are ever completely predictable?
Slide 142 / 161 Severe Weather
Some natural disasters come in the form of severe weather. How many severe weather events can you name? List them below.
Slide 143 / 161 Severe Weather
Which type of severe weather has caused the most death and destruction? Take a vote as a class and click below for the answer. Floods
Slide 144 / 161 Severe Weather
Severe weather encompasses a variety of events. We will look at
Meteorologists use the same weather data as used for normal forecasts to predict when these events will occur.
SLIDE 25 Slide 145 / 161 Hurricanes
Hurricanes are large storms that form in warm water and have winds over 74 mph. Click here to watch a video about hurricanes. As you watch, answer the following questions. 1. What are two other names for hurricanes? 2. What ocean temperature can lead to a hurricane? 3. What is the difference between a tropical depression, a tropical storm and a hurricane? 4. What creates the eye of a hurricane? 5. What technologies are being used to predict hurricanes?
Slide 146 / 161 Hurricane Classification
Hurricanes are dynamic storms that are constantly changing. Hurricanes are classified based on wind speed. Hurricane Katrina was a category 1 when it crossed
- Florida. While in the Gulf of
Mexico, it strengthened to a category 5 before weakening to a category 3 when it hit Louisiana.
Category Wind Speeds 5 Greater than 157 mph 4 130-156 mph 3 111-129 mph 2 96-110 mph 1 74-95 mph Tropical Storm 39-73 mph Tropical Depression Less than 38 mph
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Asia
N America S America Australia
Hurricanes Around the World
Hurricanes form in tropical locations where the water is relatively warm. You can see on the map that these storms do not only affect the Caribbean and the Eastern United States. These storms are called hurricanes in the Atlantic. In the Pacific, however, they are called cyclones or typhoons.
Slide 148 / 161 Hurricanes
Meteorologists are working hard on developing technologies that will help to better predict hurricane formation and path.
Click here to join a hurricane hunter flight that gathered data about Hurrican Emily.
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40 Hurricanes only form over cool ocean water. True False
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41 The eye of a hurricane is very calm. True False
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42 If a summer storm in the Atlantic has winds of 41 mph, what type of storm is it? A Tropical depression B Tropical storm C Hurricane
Slide 152 / 161 Tornadoes
A tornado is a violent, rotating funnel of air that travels from a thunder cloud down to Earth's surface. Most tornadoes reach wind speeds above 110 mph and are as wide as a football field. Some tornadoes reach speeds of 300 mph and are up to 2 miles wide!
Slide 153 / 161 Tornadoes
A tornado is the result of a severe thunderstorm. What factors create thunderstorms? Click below to see the answer. Thunderstorms form when warm, moist air and cool, dry air collide.
Slide 154 / 161 Tornado Alley
Although tornadoes can touch down anywhere in the United States, the vast majority of them form in an area known as "Tornado Alley" in the Great Plains. This area experiences a clash of air temperatures that result in large storms because of the cold dry air coming west from the Rocky Mountains and the warm moist air coming from the south off of the Gulf of Mexico.
Slide 155 / 161 Tornadoes
How many strong tornadoes have been recorded in your city?
Slide 156 / 161 Tornado Classification - Fujita Scale
All tornadoes are given a strength rating, determined by the wind
- speed. Tornadoes are graded F0-F5, with F5 being the most intense.
The scale was introduced in 1971 by Tetsuya Fujita. Rating Wind Speed (mph) 5 4 2 3 1 65-85 86-110 111-135 136-165 166-200
SLIDE 27 Slide 157 / 161 Signs of a Tornado
· Strong rotating clouds · Whirling dust and debris beneath a cloud formation · Hail or heavy rain as well as a quick wind shift · Loud continuous rumble that does not fade like thunder
Slide 158 / 161 Tornadoes
Tornadoes do massive damage to the areas where they touch down. Right now, tornadoes are not well understood. Scientists are currently able to only give about 13 minutes notice before a tornado occurs, making them quite
- unpredictable. This is often
not enough warning for people to get to safety.
Slide 159 / 161
43 A tornado can from when what two types of air masses collide? A Warm and warm B Cold and cold C Warm and cold
Slide 160 / 161
44 Tornadoes are easy to predict. True False
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45 Hurricanes and tornadoes are both classified based
A Air temperature B Humidity C Wind direction D Wind speed
