Earth Science Journal!

#21 Cloudy Condensation!
You will need a pen/pencil, crayons, and reference tables._

Notes
Two ways to increase air temperature
* Increase kinetic energy (makes atoms move faster)
* Increase pressure (makes atoms closer together)

Both of these methods increase the friction in a system!
That is why you rub your hands together to get them warm!

We must think about both methods to truly understand the water cycle.

Please write down and answer these questions.
Don't worry about getting them wrong. Just take your best guess.
1. What happens to the temperature of the air as it rises? 
2. What happens to the temperature of the air when clouds form?

Draw a puddle, grass, and a tree near the bottom of the next new page.
You may color your drawing if you like.
Leave about 2–3 inches at the very bottom of the page.

Under the puddle, write the term infiltration (water soaking into the ground).
3. What do you think infiltration means?

Draw the sun (a little higher than the tree) and write Insolation.
4. What do you think insolation means?

More Notes
Infiltration = water soaking into the ground
Insolation = Incoming Solar Radiation (Sun's energy reaching the earth)
"Insolation" is not the same as "insulation" (that pink stuff in the walls).

Notes
5. The Sun rises, and insolation heats the Earth's surface, causing evapotranspiration.
What do you think that means?

Write evaporation above the puddle and transpiration above the grass and tree.
How would you define evaporation and transpiration?

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Evaporation: Water turning into water vapor.
Transpiration: Water evaporates through plants.

Evapotranspiration: Total amount of water vapor entering the atmosphere.

Where is evapotranspiration (evaporation + transpiration) happening in our picture?

6. Does humid air rise or sink?
Hint: Remember the water balloon that we put into the microwave?
What happened to its weight?

The balloon weighed less because water vapor is a light gas!

Air feels muggy when humid, but the air is lighter (less dense) and rises!
"More humid air rises."

Draw a small parcel of air above the puddle and grass with dotted lines.
Draw the sun higher in the sky. 

 To truly think about temperature, we must think on an atomic scale!

Notes
7. What happens to the temperature of the air as it rises?
♦ As the air rises, air pressure lowers, allowing air to expand.
♦ Expanding air cools because there is less friction between molecules.

This is called adiabatic cooling.
(Click Explore)

Click to Run

https://phet.colorado.edu/sims/html/gas-properties/latest/gas-properties_en.html

Find this image in your reference tables.

As air rises in the Troposphere!
Air pressure decreases
Air temperature decreases
All weather occurs in the troposphere!

8. Do you remember the three ingredients needed to make a cloud?
Air, Water Vapor, and Dust!

9. What happens when the air temperature cools to the dew point temperature?
♦ When the air rises and cools to the dew point temperature,
condensation forms on tiny dust particles, creating cloud droplets. 
♦ These cloud droplets are what make puffy clouds.

Condensation nuclei (dust): The surface that cloud droplets stick to.

This is how clouds form.

This is why clouds have a flat base.

That is the height that the air temperature = dewpoint temperature.

10. What happens to air temperature when clouds form?

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Cloud formation (condensation) gives off A LOT OF heat energy!
This makes that air rise even more!
Why is that important?

Check out the first page of your reference tables!

Cloud Formation (write this in your journal)

• • Hot, humid air expands and cools as it rises to produce condensation (clouds).
    
  • Condensation heats the air, making it rise, expand, cool, condense, and heat more, making it rise more...etc...
  • The cloud can quickly billow as it grows upward!
    
  • Depending on the amount of water vapor in the air and how quickly the air rises, we can get wild thunderstorms, lightning, and even tornadoes!

Our sun adds a lot of energy to the atmosphere by evaporating water!
When that water vapor condenses, that energy is transferred to the atmosphere! That is why hurricanes are powered by warm ocean water!

In fact. Water vapor is the strongest greenhouse gas!

Cloud droplets are VERY tiny!

About 1 million cloud droplets make up one average raindrop!
https://water.usgs.gov/edu/watercycleprecipitation.html

When the cloud droplets become big enough and heavy enough to fall through the rising air, precipitation returns that water to our puddle.

This is how our puddle becomes a puffy cloud, then back to a puddle again.

Powered by the sun and moved by convection, cloud formation is much more interesting once you know how it works.

11. Are clouds water vapor?
Why or why not?

Clouds are made up of tiny condensed water droplets!
And they are all in the troposphere!

Re-read your answers to the first questions.
Honestly, what mistakes did you make regarding cloud formation?
Fix them.

1. What happens to the temperature of the air as it rises?  Why?
Air temperature decreases because air pressure decreases.

2. What happens to the temperature of the air when clouds form? Why?
Condensation (cloud formation) heats the air because it releases energy.

11. What is air pressure?

Air Pressure = the weight of the air above you.
High Air Pressure = Cold and Dry Air
Low Air Pressure = Hot and Humid Air

Make your clouds like the artist Berndnaut Smilde
https://www.bbc.com/news/av/entertainment-arts-21034217/how-to-make-clouds-indoors-the-art-of-berndnaut-smilde

Question
Why does this cloud have a flat top?

Use your reference tables and knowledge of cloud formation to try to figure out this cloudy conundrum!

Cloudy Condensation!

*Note: This journal entry will help you with your next lab entitled "Cartoon Clouds".

Please write down these questions.
You will need your reference tables.

12. What is the dewpoint temperature of the air in this room?
13. What would form in the air if we cooled this room to the dewpoint temperature?

*We will need a psychrometer to measure our room's dry and wet bulb temperatures
and reference tables to help find the answers.

Please write down this data.
Room 202 Data
Dry bulb temperature = 19°C
Wet-bulb temperature = 9°C

Why is the wet-bulb temperature colder?

*Note: The wet bulb thermometer is not colder because of the water temperature.

Evaporation cools the wet-bulb thermometer!

Reference tables on page 12.

Find the dry bulb temperature on the side column (19 degrees Celsius).

Find the DIFFERENCE between the wet and dry bulb thermometers.
19 - 9 = 10
Circle the word difference in your reference tables, so you don't make a silly mistake.

Your answer is exactly between -5 and -2.
Be careful!
It is very easy to make a simple mistake!

A number line may make it easier.

Please write down and answer the following two questions.

12. What is the dewpoint temperature of the air in this room? -3.5°C
13. What would form in the air if we cooled this room to the dewpoint temperature?
A cloud of SNOW, because the dewpoint is below zero degrees celsius.

14. How high must the air in our room rise to form a cloud?

To answer this question, we need to use a cloud base chart (not in the reference tables, but it is in your next laboratory). You have a Kami document of this chart, which you should open.

You need the dry-bulb temperature and the DEWPOINT temperature.

Where the two temperatures meet, cloud condensation begins!

 Draw your cloud at the correct height.

14. How high must the air in our room rise to form a cloud?
2.75 km

15. What is the relative humidity of the air in this room?

Remember to use the difference!

And the number line just to make sure.

15. What is the relative humidity of the air in this room? 21%

16. What is the relative humidity in our cloud? 100%

Remember, the dewpoint temperature and dry bulb temperature are the same in a cloud.
There is also no difference between the wet and dry bulbs because there is no evaporation. 

If you look at the Relative Humidity chart, zero difference = 100% relative humidity!

17. Why do clouds have flat bottoms?

Clouds have flat bottoms because that is the height at which the air temperature cools to the dew point temperature and water condenses onto dust particles in the air.

Dew Point + Relative Humidity + Cloud Base Height Practice

Practice Quiz

Use your Reference Tables and the Adiabatic Lapse Rate Chart to answer the following questions.

Using a psychrometer, a student obtained a dry-bulb reading of 24°C and a wet-bulb reading of 20°C.

1. What is the dewpoint temperature? 18 degrees Celsius
2. What is the relative humidity? 69%
3. What is the cloud base height for the air? 0.6-0.8 km
4. What is the temperature of the water in the reservoir?
24 degrees Celsius (same as the room temperature)
5. Why does the wet-bulb thermometer cool? Evaporation
6. What happens to the temperature in the troposphere as it rises?  Why? Temperature decreases because the air pressure decreases.

Watch the above video.

Bonus: Make a barometer and take readings for at least three days. You should make your recordings in both photos and must compare them with the actual barometric pressure readings for the dates of your data.

Earth Science Core Curriculum

Key Idea 2: Many of the phenomena that we observe on Earth involve interactions among components of air, water, and land.

2.1b The transfer of heat energy within the atmosphere, the hydrosphere, and Earth’s interior results in forming regions of different densities. These density differences result in motion.

2.1c Weather patterns become evident when weather variables are observed, measured, and recorded. These variables include air temperature, air pressure, moisture (relative humidity and dewpoint), precipitation (rain, snow, hail, sleet, etc.), wind speed and direction, and cloud cover.

2.1e Weather variables are interrelated. For example, • temperature and humidity affect air pressure, and the probability of precipitation, • air pressure gradient controls wind velocity.