Warm-up In Your Journal- What is the purpose of the atmosphere? Essential Question- Why does the Earth need an atmosphere? Does it cause any problems?

Warm-up

• In Your Journal- What is the purpose of the atmosphere?

• Essential Question- Why does the Earth need an atmosphere? Does it cause any problems?

Why do we need an atmosphere?

The atmosphere is defined as:• a thin layer of gases that

surrounds our Earth.• Without the atmosphere,

organisms that survive on Oxygen would not be able to survive. • This atmosphere also helps to

distribute the heat gained from the sun’s rays.

Composition of Air

• There are many different types of gasses in the atmosphere

• They include nitrogen, oxygen, argon, carbon dioxide and other noble gasses

• The gas that is most abundant is nitrogen

The Troposphere• Lowest (inner) layer• weather occurs here• we live in it.• “tropo” means turning or

changing conditions• depth varies from 9km

above the poles to 16km at the equator

• shallowest (least thick) layer, but contains most of the mass (90%).

The Stratosphere

• “strato” means layer or spreading out

• Contains the ozone layer which absorbs energy and causes the temperature to rise

• The ozone layer protects the surface from dangerous UV rays

The Mesosphere

• Drop in temperature marks beginning of mesosphere

• “Meso” means middle

• Most meteors burn up here

The Thermosphere• Very top layer• Air is very, very thin, about

1/1000th as dense as the air at sea level

• “Thermo” means heat• Extends from 80km to space• No definite outer edge• Very hot (over 1000°C), but

since air is so thin it would not feel warm at all.

• Divided into two parts, the ionosphere and the exosphere

The Ionosphere• Energy from sun strips the

electrons from the gas molecules creating charged particles called ions.

• Radio waves can bounce off of ions, allowing radio waves to travel great distances.

• The aurora borealis (Northern Lights) occur here

The Exosphere

• “Exo” means outer

• Extends for 1000’s of miles

• Satellites orbit here

• No definite edge• Molecules

gradually escape out into space

Occasional moleculesGradually escaping into space

Fewer moleculesLarge temperature fluctuations

ColdA few moleculesShooting stars burn up here

Ozone Layer24% of atmosphere

Life formsWeather75% of atmosphere

Fill in the correct layer of the atmosphere

Earth’s Natural Greenhouse Effect

• Greenhouse gases like water vapor, carbon dioxide, methane and nitrous oxide trap the infrared radiation released by the Earth's surface. – The atmosphere acts like the glass in a greenhouse, and

keeps the Earth 33°C warmer than it would be without an atmosphere, at an average 15°C.

Warming the Earth Naturally…

• The Sun– 25% of it’s heat is absorbed by the atmosphere – 25% is reflected by the clouds back into space. – The remaining radiation travels unimpeded to the Earth

and heats its surface. – Due to the Greenhouse effect some of this gets trapped

and can escape, thus warming the Earth Naturally

Greenhouse Effect Lab• We will work in pairs• You need One Beaker, One thermometer, parafilm to

secure the top of your beaker, and a piece of black paper

• Take your beaker outside- first record the outside air temp, place thermometer in beaker, Seal Well!! Begin observations

• We are going to gauge the temperature in each for 5 minutes, recording your observations ever 15 seconds.

• Repeat with Black paper over top of beaker

Create a hypothesis- In your Journal

• While coming up with your hypothesis, consider the following:

• Assuming you create a good seal so that little or no air flows into the jar once it is over the thermometer, how will the temperature change in the jar?

• ⇒ Will the temperature change slowly at first, then quickly? Or do you expect it to change quickly at first, then slowly?

• ⇒ What changes about the environment of the jar with the black insert placed on? How will this change the jar's rate of temperature change and its final temperature (once it stabilizes)?

• ⇒ What effect does the shade cloth have? How will it change the rate of change and final temperature in the jar?

Lab write-up

• Introduction- Using your notes write a 3 sentence introduction to the Greenhouse Effect

• Procedure- explain what you used and what you did

• Data- Include all data from both trials• Conclusion= Lab Questions

Lab Questions

• Did you prove or disprove your hypothesis?• Which experiment resulted in the highest temperature change?• Describe the general trend your temperatures took over time

(did they continuously warm up, did they have a peak and then stop warming).

• What was happening inside the bottle (describe with words AND a diagram), and how did this affect the temperature?

• What is the effect did the black paper on the top of the beaker have on temperature?

• The phenomenon you just experimented on is called The Greenhouse Effect. Explain why this term is so appropriate for this phenomenon.