MeteorologyMeteorology

(Not on Notes Page…)

Meteorology – the study of atmospheric phenomena (weather and climate).

•“Meteor” is derived from ancient Greek meaning “high in the air.”

•Clouds, raindrops, dust, fog, and rainbows are atmospheric “meteors.”

Weather – the current state of the atmosphere.

What is the weather in our area?

Climate – the long term average state Q: What is the climate in Hawaii? Alaska?

This is an image of the sunrise from space over the South China Sea. An astronaut would see something like this; clearly defined bands of color through the atmosphere as the sun rises. The brightness of the colors in the atmosphere in this photograph is due to the amount of dust in the atmosphere.

Earth’s Atmosphere

Development of the AtmosphereEarly Atmosphere

• During the 1st billion years of Earth’s formation, there was a lot of volcanic activity (Outgassing).

•Released water vapor (H2O), chlorine (Cl), carbon dioxide (CO2), hydrogen (H), and nitrogen (N).

•The Past Atmosphere: Billions of years ago the Earth’s atmosphere contained two deadly gases: Ammonia (NH3) and Methane (CH4).

•NO OXYGEN YET!

•After several million years, the planet cooled, water vapor condensed and absorbed most of the carbon dioxide.

•Storm clouds formed that produced heavy rains which formed the first oceans.

•It is believed that some of Earth’s water may have originated from numerous collisions with small collisions with small meteors and disintegrating comets* when the Earth was young. *carbon dioxide, methane and water with dust and various mineral aggregates

How did the atmosphere become safe for us?

1) Oxygen was formed from the dissociation of water molecules and by photosynthesis of primitive bacteria called cyanobacteria. This blue-green bacteria appeared 3.5 billion years ago and triggered the release oxygen as a waste product on earth.

Where did the oxygen come from cont…

2) By a slow increase in concentration as rays from the sun split water vapor (H

20) into hydrogen and oxygen.

•Hydrogen (H) drifted off to space, while Oxygen (O) remained in the atmosphere.

3) Plants also contributed to the formation of oxygen (photosynthesis: the process of using energy in sunlight to convert water and carbon dioxide into carbohydrates (sugars) and oxygen.

This image shows the average temperature profile through the Earth's atmosphere.

To Santa: MORE TOY ELEPHANTS!

Layers of the Atmosphere:Layers of the Atmosphere:The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%). Also, it contains dust and salt, which is important for the formation of clouds.

The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space.

1. The Troposphere•The lowest layer of the Earth's atmosphere.•Temperature decreases as height increases (3.6 degrees/1000 ft).•Most dense (due to compaction of molecules). •Around the equator, the height is about 16 km.•air is slightly unstable. •ALL WEATHER occurs in the Earth's troposphere!!!•0 – 11 miles up.

This is an image of the clouds in the Earth's troposphere.

2. The Stratosphere•Altitude of 50 km. (11 miles to 30 miles).

•On Earth, ozone causes the increasing temperature in the stratosphere. Ozone is concentrated around an altitude of 25 kilometers. The ozone molecules absorb dangerous kinds of sunlight, which heats the air around them.

Many jet aircrafts fly in the stratosphere because it is very stable.

If ozone is decreased, it can If ozone is decreased, it can cause:cause:

Skin cancerSkin cancer Eye cataractsEye cataracts Sun burningSun burning Suppression of the human immune Suppression of the human immune

system.system. Adverse impact on crops and animals Adverse impact on crops and animals

due to the increase of UV radiationdue to the increase of UV radiation A reduction of ocean phytoplankton.A reduction of ocean phytoplankton.

Polar stratospheric clouds, also known as nacreous clouds .

3. The Mesosphere

•Temperature decreases with altitude. (30 – 55 miles)

•The atmosphere reaches its coldest temperature of around -100°C in the mesosphere.

•Air pressure decreases.

•Does not have a lot of oxygen (at this level our brain would be oxygen-starved called hypoxia.

•This is also the layer in which a lot of meteors burn up while entering the Earth's atmosphere.

4. The Thermosphere

• 55 – 80 miles up.

The “warm layer.” This is due to the O molecules absorbing solar rays, heating the air.

• When the sun is active, the thermosphere can heat up to 2,000°C or higher!

• includes the region of the atmosphere called the ionosphere. The ionosphere is a region of the atmosphere that is filled with charged particles (ions).

• Important for radio communication.

The space shuttle orbits in the thermosphere of the earth.

5. The Exosphere

•Very high up, the Earth's atmosphere becomes very thin. The region where atoms and molecules escape into space is referred to as the exosphere.

•The exosphere is upper part of the thermosphere.

•Extends about 550 km above the surface. (80 miles and up!)

•Satellites orbit in the exosphere.

This is a picture which shows the Earth, its atmosphere (the clouds are likely in the troposphere and stratosphere), the limb of the Earth (the dark blue curve/edge which is the mesosphere and thermosphere), and the dark blue to black region of space (where our exosphere extends out to...).

Magnetosphere

•It is made up of positively charged protons and negatively charged electrons. The Earth is a large magnet.

•Van Allen radiation belts: the charged particles that are concentrated into belts, or layers of high radiation.

•When there is a solar flare, it is bombarded with electrically charges particles. Aurora borealis or northern lights.

                              

Comet Hale-Bopp in the 29 March 1997

Solar Fundamentals (Energy transfer) 3 ways:

Why Learn? Uneven heating of the Earth causes weather!

1) Radiation – transfer of energy through space by visible light, electromagnetic waves, and ultraviolet waves. Earth absorbs and reflects this energy. Sunlight is a form of radiation that is radiated through space to our planet without the aid of fluids or solids.

Radiation 20 secRadiation 20 sec

2) Convection – transfer of energy due to heat flow.

• Hot air rises, cold air sinks (density)!

• Affects weather.

*Hot substances are less dense than cold substances.

*Cool substances are more dense than hot substances.

EX. Mantle convection, wind, and wind drafts.

Convection in the oceans…

Convection 53 secConvection 53 sec

3) Conduction - is the process by which heat energy is transmitted through contact with neighboring molecules (substances – solids, liquids, and gas).

• Some solids, such as metals, are good conductors of heat while others, such as wood, are poor conductors. Air and water are relatively poor conductors.

• Since air is a poor conductor, most energy transfer by conduction occurs right at the earth's surface. At night, the ground cools and the cold ground conducts heat away from the adjacent air.

•Heat ALWAYS travels from warmer areas to cooler areas.

•Examples?

Conduction 54 secConduction 54 sec

How does this relate to our weather?

Let’s tie it all together:

radiation, convection, and conduction.

•During the day, solar radiation heats the ground, which heats the air

next to it by conduction, which can form convection currents.

1. Construct a concept map that describes the processes of the water cycle:

Water cycle

• Evaporation

• Condensation

• Precipitation

• Water changes from liquid to gas

• Water changes from gas to liquid

• Water falls as rain, snow, sleet, or hail

2. Construct a concept map using these terms :

Conduction, radiation, convection, energy transfer

Transfers energy by electromagnetic waves, occurs when molecules collide, occurs through the flow of a heated substance

11.2 State of the Atmosphere.

1) What is the difference between heat and temperature?

2) What is the difference between Fahrenheit, Kelvin, and Celsius? What temperature does water boil for each unit? What temperature does water freeze for each type of unit?

3) Define dew point and condensation.

4) What is lifted condensation level?

5) What happens to the density of air as you decrease in elevation? Why?

6) Describe the Temperature- Density - Pressure Relationship.

7) Describe why wind “blows.”

8) What is humidity? Relative humidity? How does this affect cloud formation?