Slide 1

Introduction to the Atmosphere Lutgens & Tarbuk The Atmosphere chp1CollegeNow Meteorology 31 March 11 2008

http://www.globalsecurity.org/wmd/library/policy/army/fm/3-6/3-6apc.htmElements of climate and weatherMeasurementsAir temperatureHumidityType & amount of cloudinessType &a mount of precipitationPressure exerted by airWind speed and direction

Thermometers BarometersPschycrometersRadiosondesBalloonsStationsSatellitesRocketsPlanesBuoys

ElementsThe Structure of the AtmosphereLayers of gases that extent into space.

Variations in temperature, humidity, pressure, and composition.

Components include water vapour, ozone, aerosols, Nitrogen, Oxygen, Ar, CO2, and other gases.

TroposphereStratosphereMesosphereThermosphere

The Structure of the AtmosphereTemperature varies vertically throughout the atmosphere

The Structure of the AtmosphereTemperature variation is used to define the different layers of the atmosphere

TroposphereStratosphereMesosphereThermosphere

The upper end of a layer is a pause, thus there is a tropopause , a stratopause, etc. These are zones where temperature is invariant.The Structure of the AtmosphereTemperature variation is used to define the different layers of the atmosphere

TroposphereStratosphereMesosphereThermosphere

The upper end of a layer is a pause, thus there is a tropopause , a stratopause, etc. These are zones where temperature is invariant.

After Lutgens and Tarbuk, The Atmosphere Figure 1-25The Structure of the AtmosphereSome phenomena are correlated with specific layers of the atmosphere

Troposphere: Layer of mixing of gases, also the Sphere of WeatherStratosphere: Residence of Ozone layerThermosphere: Site of Aurorae

After Lutgens and Tarbuk, The Atmosphere Figure 1-25What causes vertical variation in Temperature?What causes vertical variation in Temperature?Temperature is decreasing with height, the further away from the warm, radiating surface of the earth, the lower the temperature of the air mass.

In the Troposphere, for every kilometer of increase in altitude, there is a 6.5C drop in temperature (called the normal lapse rate)But Temperature increasesTemperature increases in a few layers of the atmosphere.

What layers?

Image after: http://wpos12.physik.uni-wuppertal.de

But Temperature increasesTemperature increases in a few layers of the atmosphere.

What layers?

StratosphereThermosphere

Image after: http://wpos12.physik.uni-wuppertal.deBut Temperature increasesTemperature increases in a few layers of the atmosphere.

What layers?

StratosphereThermosphere

Temperature increases for different reasons in the two spheres.

Image after: http://wpos12.physik.uni-wuppertal.deStratosphere Temperature increaseThe air mass needs to receive heat in order to be wamed. Closer to the earths surface, it is the heat that is radiating from the earth that warms the air.

In the stratosphere, the energy to heat the air comes chemical reactions, ultimately through UV radiation, in the ozone-oxygen cycle

Image after: http://wpos12.physik.uni-wuppertal.deStratosphere Temperature increaseThe air mass needs to receive heat in order to be wamed. Closer to the earths surface, it is the heat that is radiating from the earth that warms the air.

In the stratosphere, the energy to heat the air comes chemical reactions, ultimately through UV radiation.

Ozone is present in high concentrations in the stratosphere. It is created and destroyed in the ozone-oxygen cycle.

Image after: http://science.howstuffworks.com/earth5.htm

Step 1Step 2Stratosphere Temperature increaseThe air mass needs to receive heat in order to be wamed. Closer to the earths surface, it is the heat that is radiating from the earth that warms the air.

In the stratosphere, the energy to heat the air comes chemical reactions, ultimately through UV radiation, in the ozone-oxygen cycle

Image after: http://science.howstuffworks.com/earth5.htm

Step 1: Oxygen Molecule absorbs UV light and splitsStep 2: Oxygen atom reacts with molecular oxygen creating ozoneStratosphere Temperature increaseThe air mass needs to receive heat in order to be wamed. Closer to the earths surface, it is the heat that is radiating from the earth that warms the air.

In the stratosphere, the energy to heat the air comes chemical reactions, ultimately through UV radiation, in the ozone-oxygen cycle

Image after: http://science.howstuffworks.com/earth5.htm

Step 1: Oxygen Molecule absorbs UV light and splitsStep 2: Oxygen atom reacts with molecular oxygen creating ozoneWhen Step 2 is run backwards, Ozone absorbs UV radiation, splits into molecular and atomic oxygen, and heat is added to the stratosphere

Ever hear of Ozone Depletion?The Ozone molecule, as we have seen, is absording solar radiation. The Ozone layer is created by the sun, and it protects the earth beneath it from the sun.

It is the result of a chemical process. Like any other chemical process, it can be interfered with.

Chlorofluorocarbons can react with ozone in the atmosphere, and prevent the formation of ozone.Image after: http://www.safety-devices.com/what_is_ozone.htm

Ever hear of Ozone Depletion?CFCs are normally stable compounds. They get into the air, are pushed up into the stratosphere by wind currents, and there are exposed to UV rays.

The UV rays break the bonds that hold the CFCs together, releasing free Chlorine.

That cholorine reacts with ozone, stripping off one of its oxygens. Other free oxygen in the atmosphere can react with the Chloro-oxide, creating molecular oxygen, leaving the Chlorine free to rip apart other ozone molecules.Image after: http://www.safety-devices.com/what_is_ozone.htmChlorine and Ozone reactChlorine is liberated to react again with Ozone

Ever hear of Ozone Depletion?Image after: http://www.safety-devices.com/what_is_ozone.htmChlorine and Ozone reactChlorine is liberated to react again with OzoneCFCs can destroy ozone molecules, this competes again the action of UV rays creating ozone.The Ozone HoleImage after: http://www.theozonehole.com

The Ozone HoleImage after: http://www.theozonehole.com

After Lutgens and Tarbuk, The Atmosphere Figure 1-25What about the Thermosphere temperature increase?So we can explain the temperature increase in the stratosphere as a result of energy input from the sun.

In the Thermosphere, there is a similar effect. Oxygen and Nitrogen in the layer are bombarded by high energy solar radiation (short wave, think like how microwaves can heat things). This causes an increase in temperature within the Thermosphere.

To what temps?

After Lutgens and Tarbuk, The Atmosphere Figure 1-25What about the Thermosphere temperature increase?To what temps?

Here we see up to 50C, but temperatures actually get up to 1,oooC

After Lutgens and Tarbuk, The Atmosphere Figure 1-25What about the Thermosphere temperature increase?Up to 1,oooC

However:

HEAT IS NOT THE SAME AS TEMPERATURE

Heat is not the Same as TemperatureTemperature: A statistical property of objects, a measure of the movement of its component molecules. Fast moving particles mean an object has a high temperature.

Heat: A measure of energy

So what does that mean about the Thermosphere????Heat is not the Same as TemperatureTemperature: A statistical property of objects, a measure of the movement of its component molecules. Fast moving particles mean an object has a high temperature.

Heat: A measure of energy

So what does that mean about the Thermosphere????

The air molecules are very ,very fast moving. A sample of it has low heat energy.

If an astronaut put their hand out into the thermosphere, it sure wouldnt feel hot.

After Lutgens and Tarbuk, The Atmosphere Figure 1-25Variation in vertical StructureWhat is the altitude of the Tropopause?

10 km?

After: http://www.csulb.edu/~rodrigue/geog140/lectures/thermalstructure.htmlVariation in vertical StructureTropopause position varies with latitude.

At the Poles, it can be as shallow as 8 km. This is because air at the poles is in fact sinking.

At the equator, it can reside at an altitude of 18 km. This is because the warm, moist air of the equator is rising through the atmosphere.

In the Middle Latitudes, the Tropopause is higher in the summer and lower in the winter.

After Lutgens and Tarbuk, The Atmosphere Figure 1-25So.The atmosphere is divided into layers on the basis of temperature, the Troposphere, the Stratosphere, the Mesosphere, and the Thermosphere.

The Troposphere is where most weather and clouds occur.

Normally, the further away from the surface of the earth, the cooler the air. But in the Stratosphere, the absorption of UV radiation by the ozone layer heats up the Stratosphere. And in the Thermosphere, absorption of shortwave radiation by Oxygen and Nitrogen molecules heat the Thermosphere.

Variations other than TemperatureWe can also divide the atmosphere into layers based air composition.Variations other than TemperatureHomosphere: Zone within which the ratio of components (Oxygen, Nitrogen, CO2, etc) does not vary much. Up to 80 km

Heterosphere: Zone within which the ratio of components varies greatly. The lowermost layer is dominated by N2, then a layer of atomic Oxygen, then a layer dominated by Helium (He), and then the highest layer, dominated by atomic Hydrogen (H). Notice, the heaviest elements are lowest, and the lightest elements float in a layer above that. Earth actually looses H and He to space at the outer edge of this sphere, gravity is insufficient to hold those gases to Earth. Also, the density of gases becomes extremely low in this layer. Said to occur from 80-10,000 km

Variations other than TemperatureIonosphere: Region where N2 and Oxygen atoms are ionized; high energy rays strip off some of their electrons (iow, they become Ions). b/t 80-400 kmD & E Layer: Ephemeral. At night, when there is no influx of solar radiation, the ions disappear, reappearing during daylightF Layer: Constant, but very weak. Low density of atoms and molecules prevents ions from disappearing, so they last throughout the night.

Aurora: borealis and australis

Interaction between electromagnetic solar wind and the earths magnetic field. The solar particles are directed to the poles, where they interact with molecules in the atmosphere, energizing them, creating lights.Variations other than TemperatureAerosols: Particulate matter suspended in the atmosphere, smoke, dust, etc.

After: http://namma.nsstc.nasa.gov/reporting/large/Atmospheric Structure

After: http://www.csulb.edu/~rodrigue/geog140/lectures/thermalstructure.htmlAtmospheric StructureAfter: http://www.csulb.edu/~rodrigue/geog140/lectures/thermalstructure.html

Titans AtmosphereEarths atmosphere is not, clearly, the same as other planets, neither in composition nor strucuture.

Jupiters AtmosphereEarths atmosphere is not, clearly, the same as other planets, neither in composition nor strucuture.

After: http://cseligman.com/text/planets/jupiteratmostruct.jpgJupiters AtmosphereJupiter has Aurora also, however they result from interactions between Jupiters magnetic field and its moons. This is a UV image.After: http://cseligman.com/text/planets/jupiteratmostruct.jpg

Jupiters AtmosphereJupiter, and other planets, have weather. But it is wildly different than on earth. The Great Red Spot is a storm that has been observed ever since Jupiter has been telescopically observed (iow, +300 years), and is as big as the entire surface area of the earth. The smaller red spot below it has a diameter as large as that of earth. The red storms are thought to have stirred up material from deeper within jupiter, while the white storms arent strong enough to reach below its atmosphere.

Notice the banding of the atmosphere in this image, this is zonal banding, it occurs on earth too. After: http://cseligman.com/text/planets/jupiteratmostruct.jpg

More on structure:Atmospheric Circulation Cells: Convecting cells of rising and sinking air that carry moisture and heat with them across earth

Afterhttp://www.climateprediction.net/science/cl-intro.php

More on structure:Atmospheric Circulation Cells: Convecting cells of rising and sinking air that carry moisture and heat with them across earth

Afterhttp://www.climateprediction.net/science/cl-intro.php

More on structure:Atmospheric Circulation Cells: Convecting cells of rising and sinking air that carry moisture and heat with them across earth

Afterhttp://www.climateprediction.net/science/cl-intro.php

SoThe atmosphere can be divided into four layers based on temperature, the Troposphere, Stratosphere, Mesosphere, and Thermosphere.

There is vertical variation of temperature within those layers, and you can explain that variation

The atmosphere can also be divided into layers based on their composition, such as the Homosphere and Heterosphere or the Ionosphere

Some components, like Ozone, can have their atmospheric concentrations changed by biological activities (human or otherwise)The altitudes at which the boundaries for the layers (the pauses) occur is not the same throughout the world. There is variation in all directions.

The rate of temperature change is not the same within the layers throughout the world, it varies too, largely with changes in latitude.

In fact, all characteristics can vary between different locations on the earth, with respect to latitude and longitude. We will find that latitudinal variation is often related to Insolation.Keep in Mind