Weather, Climate, and the Atmosphere

Composition of the Atmosphere

What is weather?

• Weather is the condition of the Earth’s atmosphere at a particular time and place.– Example: What is the weather outside right

now?– Not an Example – What is North Carolina

weather in the fall?

Climate

• An AVERAGE of weather conditions over a long period of time

What is the Atmosphere?

• Remember! • Atmos – Vapor

Sphere – Ball

• The Atmosphere is a layer of gases that surround Earth or any planet.

Why is the atmosphere important:

1. We need the gases for survival.

2. It prevents the earth from being hit by meteoroids

3. Heats the water on earth to keep most of it in liquid form

4. Protects us from the

What keeps the atmosphere in place?

• Gravity hold our atmosphere to the earth!

• The atmosphere is attracted to the center of the earth like all other objects

What is in our atmosphere?

Gases (dry air)

1. Nitrogen 78% - N2

2. Oxygen 21% - O2

What else is in the atmosphere?

3. Carbon Dioxide - less than 1% - CO2

4. Trace Gases – less than 1% of argon, helium, methane, krypton, ozone & hydrogen

Wet Gases

• Water Vapor – Water in the form of a gas

• The amount of water vapor varies from 0 – 5%.

• Example – Desert – O%

• Example – Rainforest – 5 %

What does CO2 do to the atmosphere?

• It heats our atmosphere!

• It takes very little!• This is why we are

concerned about the greenhouse effect and global warming.

• But more on that later…

What was the early earth like?

• Little or no oxygen!

• CO2 was the most abundant gas in our atmosphere

• Very high temperatures

• No living creatures

What changed the earth’s atmosphere?

• After creation, the big bang, or someone sprinkled some magic dust…

• The first life forms appeared…

• Bacteria that takes in CO2 and gives off oxygen as waste

• This made the earth a cooler place where evolution could occur

Layers of the atmosphere

Jigsaw, picture graph, temperature inversions

Properties of Air

Does AIR have MASS?

• YES!!

• Now that we know it has “stuff” in it (matter) then we also know that it has density and pressure!

Density of Air

• The amount of mass in a given volume of air.

• If there are more molecules in a given volume then the density is greater. If there are less the density is less!

Altitude affects density

• As altitude increases, density decreases

• As altitude decreases, density increases.

Air also has PRESSURE…

• The force pushing on an area or surface is known as PRESSURE

Air pressure is…

• The result of a column of air pushing down on an area.

• Example: Books on the belly

Altitude affects air pressure

• Air pressure increases as altitude decreases

• Air pressure decreases as altitude increases.

Let’s summarize

• As altitude increases, air pressure ______

• As altitude increases, temperature _____

• As altitude increases, density ______

Falling Air pressure means that a storm is approaching

Rising air pressure means the weather is clearing

How do you measure Air pressure?

• Mercury barometer• Measured in inches

• Aneroid barometer• Measured in millibars

PollutionPollution

What is a Pollutant?

• Harmful substances in the air, water or soil.

Pollutants

• Particles

• Examples:– Dust– Smoke– Salt– Other Chemicals

Is it OK to be dirty?

• YES!! (to a certain degree)

• When water vapor condenses to form clouds it must have something to stick to in the atmosphere.

• Natural pollutants are just the thing that clouds need.

Is some pollution OK?

• YES!!• Salt Spray• Mold• Pollen• Erosion• Forest Fires• Dust Storm• Animal Dander• Volcanic Eruption

• These are all Natural Pollutants.

BUT SOME IS NOT!!

• Un- natural Pollution = Human Activities

• ½ - motor vehicles

• ¼ - factories and power plant

• ¼ - farming, construction, burning fossil fuels (wood and coal)

The increase of un-natural pollution is causing the following

three problems:1. Smog

2. Acid Rain3. Greenhouse Effect/Global

Warming

Smog = Smoke + Fog

• London Smog – coal particles + Water Vapor in the humid air in England

• Photochemical Smog - sunlight + chemicals in the air released by motor vehicles and factories

Acid Rain

• Chemicals called oxides mix with water in the air to make the rain acidic (Draw this)

• Precipitation carries acid from the air to trees, water sources, and buildings

ACID RAIN

• Nitrogen Oxide in atmosphere + water

Turns into NITRIC ACIDOr

• Sulfur oxide in atmosphere + water

Turns into SULFURIC ACID

Precipitation carries acid from air to trees, lakes and buildings!!

Examples of damage:

The greenhouse effect

• the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun.

• The greenhouse effect alone is a natural event…however…

Increased Green House gases are causing global warming…

• http://epa.gov/climatechange/kids/global_warming_version2.html

NOW WHAT?

• Pollution Restrictions by US Government

• Factories install filters on smokestacks

• Higher standards for clean cars

• More affordable and reliable Hybrid/electric vehicles