Earth's Atmosphere

Earth's Atmosphere

By Mario Miro

Atmospheric Composition - What is our air made of?

• Many years ago air was thought to be one of the fundamental elements

  from which all other substances were made.​

• In fact air is a combination of gases such as Nitrogen (78%),

  Oxygen (21%), Carbon Dioxide (.04%),water droplets, ice crystals

  and particles of dust.​

• Our atmosphere extends from Earth's surface to outer space.​

Permanent Atmospheric Gases - Gas composition of our atmosphere that basically never changes.

• 99% of our Atmosphere (Air) is composed of Nitrogen, and Oxygen​.

• 1% of of our atmosphere consists of other gases, Argon, Carbon Dioxide,

  and water vapor​

Earth's Atmosphere

• The amount of these gases is pretty constant over recent times.​ as our atmosphere recycles these gases on a continuing basis

• Understand that our atmosphere over millions of years has gone over many different changes. In Earth's early life our atmosphere was basically composed of helium, hydrogen, methane and ammonia. ​

Variable Atmospheric Gases​ - Gases that change in amount of concentration, it changes in different places and times. These are mostly:

• Carbon Dioxide, Water Vapor and Ozone (O3)

• These gases play a major role in regulating the amount of energy that is absorbed by our atmosphere

• Ozone (O3) - is very important to the maintaining of our atmosphere​, Changes can cause global warming and be harmful to our earth's surface.

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Earth's Atmosphere

Atmospheric Layers - Our atmosphere is classified into 5 different layers, they differ in altitude, temperature, and composition:

• Troposphere - is the closest to our earth's surface. (surface to about 10 Km above the surface)

  • Contains the most mass of our atmosphere

  • Weather occurs in this layer, also planes fly here

  • Air temperature decrease with altitude, The altitude at which air temperature stops decreasing is called the Tropopause (top of Troposphere). This point can varies from 16Km (Equator) to 9km (Poles)

• ​Stratosphere - Above the troposphere (10km to 50km)

  • Air Temperature increases with altitude​

  • The Ozone layer is contain within the Stratosphere (20km to 50km)

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Earth's Atmosphere

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  • In the lower part (10km to 20km) of the stratosphere the temp. basically is consistant, but in the ozone the temp increase as we increase our altitude. This is caused by the ozone absorbing more UV energy from the sun.

• Mesosphere - This is the area above the stratosphere (50km to 85km) above the surface of the earth.

  • Air temp decreases with altitude due to very little Sun energy being absorbed in the layer

  • Coldest of the atmospheric layers

  • At the top of the mesosphere where air temp stops decreasing is called the mesopause.

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Earth's Atmosphere

• Thermosphere - is the layer that is found above the mesosphere at about 85km to 600km.

  • Air mass is low density, causing air temps to rise with altitude

  • This is the layer where we find that our spaceship travel in:

    • ISS (International Space Station)

    • other spaceships that have recently flown into space

  • Air temp can rise up to 2000*C

• Exosphere - outermost layer of earth's atmosphere (600km to over 10,000km) no clear boundary.

  • Thought of as the transitional region into outer space

  • Atmosphere is very low density, atoms and molecules are far apart

Earth's Atmosphere

Multiple Choice

the outermost region of a planet's atmosphere; gas molecules finally become so scarce that at some point there are no more

• Exosphere

• Ionosphere

• Troposphere

• Endosphere

Multiple Choice

Which layer of the atmosphere do pilots prefer to fly in?

• stratosphere

• thermosphere

• troposphere

• endosphere

Multiple Choice

the layer closest to Earth, where almost all weather occurs; the thinnest layer; decreases with altitude

• Troposphere

• Thermosphere

• Stratosphere

• Ionosphere

Multiple Choice

What are the two most common gases in the atmosphere?

• hydrogen and oxygen

• nitrogen and water vapor

• hydrogen and nitrogen

• oxygen and nitrogen

Multiple Choice

Ozone is a type of oxygen.

• True

• False

Multiple Choice

Water vapor is one of the two main gases found in

Earth's atmosphere today

• True

• False

Multiple Choice

What is the coldest layer of the atmosphere?

• Mesophere
• Thermosphere
• Stratosphere
• Troposphere

• Layers of the Atmosphere (Animation) - YouTube

​Properties of the Atmosphere

• Temperature - is the measure of the average kinetic energy of the particles in the material​

  • Temperature is measured 2 common scales:

    • Fahrenheit (F) - Water boils (212 F), water freezes (32 F), Absolute Zero (-459 F)

    • Celsius (C) - Water boils (100 C), water freezes (0 C), Absolute Zero (-273 C)

    • Kelvin (K) - Scientific Scale - Water boils (373 K), water freezes (273 K), Absolute Zero (0 K)

Earth's Atmosphere

• Air Pressure - is the pressure exerted on a surface by the weight of the atmosphere above the surface, measured in newtons/square meter (N/m2) or millibars (mb), (1mb =100N/m2), At sea-level air pressure = 1000mb, Increasing in altitude, decreases air pressure

• Density of Air - is the mass of material in a volume, such as (1 m3)

  • Density of Air decreases as we increase altitude

  • Air Density @ sea level is 1.2 kg/m3

• ​Wind - movement of air

  • Wind is mainly due to a difference in air pressure.

    • hot air less dense and lower pressure

    • cold air greater density and high pressure

• ​Example - Colder air-conditioned building as you open door. You feel the rush of colder air coming at you.

Earth's Atmosphere

• Wind speed is most often determined by altitude

  • high altitudes cause increased wind speed as the wind is not subjected to the friction of the earth's surface.

• Humidity - is the amount of water vapor in the atmosphere at a given location on the earth's surface.

  • Relative Humidity - amount of water vapor in a volume of air relative to the amount of water vapor needed to for that volume of air to become saturated

  • Dew Point - is the temperature to which air must be cooled at constant pressure to reach saturation

Earth's Atmosphere

Multiple Choice

As you rise upwards in the atmosphere, air pressure __?__.

• increases

• decreases

• doesn't change

Multiple Choice

Winds are caused by differences in __?__.

• precipitation

• air pressure

• humidity

Multiple Choice

The force of a column of air pressing down is called what?

• Air Mass
• Air Pressure
• Air
• Heavy

Multiple Choice

The amount of water vapor in the air is known as ___.

• dew point

• humidty

• relative humidity

• rain

Multiple Choice

When the air is full of water and has a relative humidity of 100% it is said to be ___.

• full

• humid

• saturated

• warm

Multiple Choice

Items in the air that are required for clouds to form

• dust

• condensation nuclei

• minuscule particles

• hail

Clouds and Precipitation

• Clouds can form when a rising air mass cools​

• Remember hotter air rises as it is less dense then colder air. Also, air on the surface of the earth warns and cools at different rate so, we will have different air masses rising or sinking as this happens.

• As, air rises it cools and condenses causing the formation of a cloud.

  • As, the air condenses into water droplets they attach themselves to small particles (condensation nucleus), causing the formation of CLOUDS

• Clouds formation is also dependent on the stability of the air, meaning are the air masses rising or falling due to temperature changes

Earth's Atmosphere

• Types of clouds, formed at different altitudes and having different shapes

  • 3 classes of clouds based on the altitude they were formed, low, middle, and high clouds

    • Low clouds - usually form below 2000m (Cumulonimbus - low cloud with vertical development)

      • Cumulus - puffy, lumpy-looking cloud

      • Stratus - sheet-like(Blanket) covers much of the sky

      • Stratocumulus - cumulus cloud flattened out horizontally by the wind

      • Nimbostratus - low clouds that produce precipitation, can cause thunderstorms

    • Middle clouds - between 2000m and 6000m

      • Altocumulus and Altostratus - made of ice crystals and water droplets due to colder temperatures

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Earth's Atmosphere

Earth's Atmosphere

• ​High Clouds - made of ice crystals and formed at heights above 6000m.

  • Cirrus - often wispy, indistinct appearance

  • Cirrostratus - forms as a continuous layer, that can be transparent or thick covering the light from the sun or the moon

  • Cirrocumulus - has a rippled effect in the shy

Precipitation

• Precipitation - Any type of water falling from clouds to the ground. 4 main types

  • Coalescence - when water droplets collide with each other to form larger water droplets​, which then fall to earth

  • Rain - is precipitation that reaches earth's surface as a liquid

  • Snow, Sleet and Hail - Type of precipitation that reaches earth with cold temperature aloft and/or at the surface

Multiple Choice

Which type of cloud is described as being high and wispy?

• cumulus

• cirrus

• stratus

• cumulonimbus

Multiple Choice

Clouds with the prefix alto- are found where in the troposphere? Also, many cumulus clouds are found here too.

• High

• Middle

• Low

• Very Low

Multiple Choice

True or False: Solid particles that water vapor condenses on to form a cloud is condensation nuclei

• false
• true

Multiple Choice

Clouds are formed by the process of ______________________.

• precipitation

• evaporation

• condensation

• collection

Multiple Choice

What kind of precipitation is formed when water falls from the clouds and lands on the ground as liquid water?

• Hail
• Sleet
• Rain
• Snow