Lesson E8: How Water and Oceans Affect Climate

Key Ideas     Unit Checklist

  Video Lesson

How does water affect the climate of places around the world? Watch this video to learn more about how water and oceans affect climate.

 
 

  Lesson E8: How Water and Oceans Affect Climate


Figure E.2.8.1 – Warm Chinook winds blow across southern Alberta.

Figure E.2.8.2 – An arch of high, still clouds accompanies Chinook winds.


Figure E.2.8.3 – Chinook winds form when air travels down mountains.
Reading and Materials for This Lesson

Science in Action 8
Reading: Pages 366–370

Materials:
Glass jar (1 L capacity or larger), kettle, water, oven mitts, matches, zipper-seal sandwich bag, ice cubes.

Chinook Winds

Wind carries moist air from the Pacific Ocean east over the Rocky Mountains. As this moist air moves up the mountains, it cools. The moisture in the air condenses into clouds, which drop rain and snow over the mountains. The air becomes dry and continues to move eastward. As dry air travels down over the other side of the Rocky Mountains into Alberta, it warms up.

In Alberta, these warm winds from the mountains are called Chinooks. Southern Alberta gets very strong Chinook winds, especially in the Lethbridge area. For this reason, many of Alberta’s wind turbines are located close to Lethbridge. Warm Chinooks are especially dramatic in the winter, when they can increase the temperature by 20 to 30 degrees Celsius in just a few hours.



 Watch More

Chinooks

Not every warm day in the winter is because of a chinook. Watch this video to see all of the things that happen when a chinook starts to blow.

 
 
Figure E.2.8.4 – Cumulus clouds are fluffy, like cotton balls.
Figure E.2.8.5 – High cirrus clouds are thin and feathery.

Clouds

After liquid water evaporates from Earth’s surface, it travels high into the atmosphere as water vapour. At high altitudes, the atmosphere’s temperature becomes colder. This causes water vapour to condense back into liquid water.

Water particles do not automatically join to form liquid drops. They need to gather around a different liquid or solid surface. Dust particles in the atmosphere provide a tiny surface for water particles to collect around and form tiny liquid water droplets. A large collection of water droplets in the atmosphere makes up a cloud.

Clouds have different shapes. Low-hanging stratus clouds are big still sheets of clouds. Stratus clouds produce rain and snow. Cirrus clouds are thin, wispy clouds located very high in the atmosphere. Cirrus clouds indicate that the weather is going to change soon. Cumulus clouds are fluffy and can grow into tall thunderstorm clouds, which are called cumulonimbus clouds.

Figure E.2.8.6 – Rain and snow come from low-hanging stratus clouds.
Figure E.2.8.7 – Cumulonimbus clouds produce thunderstorms.

 Watch More

Many Different Clouds

Watch this video to learn more about how clouds form.

 
 
 
 
This video explains why water droplets in clouds form around particles of dust.

 
 
 
 
Watch this video to learn more about different types of clouds.

 
 

  Try It! 

Cloud in a Jar

Try this simple experiment to create a cloud.

Materials: 
  • Glass jar (1 L capacity or larger)
  • Kettle
  • Water
  • Oven mitts
  • Matches
  • Zipper-seal sandwich bag
  • Ice cubes

This activity involves hot water and matches. It must be completed with the supervision of an adult. DO NOT attempt this activity by yourself.

Hot water and matches can burn you or others if you are not careful.
Wear oven mitts when handling the electric kettle.
Take care when pouring hot water.
Make sure that matches are fully extinguished before throwing them into the garbage.
Instructions:

  1. Boil water in the kettle.

  2. Fill the sandwich bag with ice cubes. Seal the bag and set aside.

  3. Fill the glass jar with boiling water. Let the water sit in the jar for 2 minutes.

  4. Put on oven mitts to handle the hot jar. Pour out most of the water in the jar, leaving about 1 cm of hot water in the bottom. Place the jar back down on a flat surface.

  5. Light a match and hold it over the top of the glass jar for several seconds.

  6. Drop the match into the jar.

  7. Immediately cover the top of the jar with the bag of ice cubes. What do you observe?

  8. Watch this video to see this a similar experiment and its results:

 
 

Question: 

Think about the following question very carefully. Then, type or write your answer. When you have your answer, click the question for feedback.

Water vapour needs a surface to condense around. Smoke particles from the lit match provided a surface that the water vapour could collect around, to form tiny droplets.
Figure E.2.8.8 – Some clouds form severe thunderstorms and hailstorms.
Figure E.2.8.9 – Thunderstorms can produce huge hailstones.


Figure E.2.8.10 – Hailstones damage roofs, cars, and plants.
Hailstorms

Severe thunderstorms happen often during Alberta summers. Some thunderstorms produce hail. Some hailstones are small, like tiny pebbles. Some hailstones are as big as a golf ball.

Strong convection current winds in a thundercloud produce hail. Rising warm air in the cloud pushes water droplets upward. High in the atmosphere, the temperature is cold enough for these water droplets to freeze into hail. Additional layers of ice freeze around hailstones until they become too heavy for the thundercloud winds to lift.

Falling hail damages crops, buildings, and animals. The force of falling hail can hurt people too. You should always find shelter when you see or hear a thunderstorm approaching.

 Watch More

Hailstorms

These videos explain how hail forms in clouds.

 
 
 
 
 
 
Figure E.2.8.11 – Canada’s coastlines have a humid climate.
Figure E.2.8.12 – The Great Lakes create a humid climate in southern Ontario.


Figure E.2.8.13 – Alberta has low humidity, especially in the winter. Skin can become dry and itchy as a result.
Water in the Air

Places located close to large bodies of water are more humid. Humidity describes the amount of water vapour in the air. Alberta has a dry climate with low humidity. Coastline communities in Canada have high humidity, due to water evaporation from the ocean. Southern Ontario is also very humid, because of water evaporation from the Great Lakes.

Humidity makes the air temperature feel more extreme to humans. During summer, humidity makes the air feel hotter than it really is. In winter, humidity makes the air feel colder.

Weather forecasters describe humidity with the humidex, which stands for humidity index. The humidex is a number that describes how the temperature feels to people, taking humidity into account. For example, in a humid location, the actual air temperature might be 25°C, but the air feels warmer than it actually is. In this case, the humidex temperature might have a reading of 32°C.

 Watch More

Humidity

Watch this video to learn more about humidity and how it is measured.

 
 

  Connections 

Figure E.2.8.14 – The amount of frozen water in the Arctic is declining as global temperatures increase.
Figure E.2.8.15 – Large areas of land are experiencing several years of extreme droughts.


Figure E.2.8.16 – Climate change can lead to larger, more frequent storms.
Connections – Environment
>> Climate Change
Earth’s temperature has increased and decreased over time, due to natural causes such as Earth’s wobbly tilt and random tectonic plate movement. In the last 200 years, Earth’s average temperature has risen quickly and dramatically. Most scientists agree that global warming is caused by humans burning fossil fuels, which puts heat-trapping carbon dioxide into the atmosphere.

Rapid global warming can change the long-term weather patterns, or climates, of different places on Earth. This is why global warming is also referred to as climate change. Increased global temperatures affect the water systems on Earth, which largely influence climate. For example, melting ice caps add freshwater to oceans. This can change ocean currents, which affect the climate on land. Warmer temperatures also cause increased water evaporation over the oceans. More water evaporation creates stronger tropical cyclones, which flood and damage coastal communities.

Climate change has serious consequences for all living things. A changing climate affects the habitats of all living things. For example, if areas becomes hotter and drier, droughts can occur. When plants cannot grow due to lack of water, people and animals starve.

 Watch More

Weather and Climate Change

What is the difference between weather and climate? Watch this video to learn more.

 
 
 
 
Watch this video to learn more about climate change.

 
 
 
 
This video explains why climate change creates stronger storms and extreme weather.

 
 
 
 
Hurricane Sandy was an extremely destructive tropical cyclone that hit the Caribbean Sea and North American east coast in 2012. Why does climate change cause severe hurricanes like Sandy to happen more often? Watch this video to learn more.

 
 


Ocean Currents

Ocean currents are like rivers in the ocean. Some people describe ocean currents as a conveyor belt. Water circulates around the world because of ocean currents. Some ocean currents are warm, and some are cold.

Click here to Explore with Elsie about ocean currents.



  Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.

Unit E Lesson 8 Self-Check

Instructions


Complete the following 6 steps. Don't skip steps – if you do them in order, you will confirm your understanding of this lesson and create a study bank for the future.

  1. DOWNLOAD the self-check quiz by clicking here.

  2. ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.

  3. COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.

  4. REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.

  5. SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.

  6. CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!

Be a Self-Check

Superhero!



Self-Check Quiz Answers

Click each of the suggested answers below, and carefully compare your answers to the suggested answers.

If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.

The Gulf Stream carries warm water from the Gulf of Mexico across the Atlantic Ocean to northern Europe, including Scotland. The warm water in the Gulf Stream heats the air above it. This makes winter temperatures on the Atlantic coast of Europe warmer than other places with the same latitude.
Cold water from melting ice sheets could disrupt the warm Gulf Stream current. This could create a colder climate in northern Europe.
Tropical cyclone storms form when large amounts of water evaporation from the ocean. Ocean water is warmer and evaporates faster during the summer and fall months. More water vapour in the atmosphere creates larger storms. Ocean water is colder in the winter, so not as much water evaporates to form cyclones.
Severe storms cause more damage to coastal communities. Strong winds in a storm can knock down trees, power lines, and damage buildings. Heavy rain can cause flooding in coastal communities. The damage caused by severe storms can put people’s lives in danger. It also requires a lot of money to clean up and fix the damage caused by storms.
Calgary is closer to the Rocky Mountains than Edmonton, so it receives warm Chinook winds during the winter. Warm Chinook winds form when moist air from the Pacific Ocean drops rain and snow over the Rocky Mountains. The dry air keeps moving over the mountains and warms up as it travels down toward the prairies.