Weather

Learning Goal:Comprehend the 3 ways energy moves through the earth’s atmosphere.

Energy of the Atmosphere

Sun – 98% of the energy in Earth’s atmosphere comes from the sun in the form of electromagnetic waves.

Radiation – is the direct transfer of energy by electromagnetic waves.

-visible light most

- infrared

-ultraviolet

Blue sky – is the product of the reflection and scattering of light in all directions causing the short wavelengths of blue and violet to appear.

Dusk and Dawn – the scattering of longer wavelengths (red and orange) due to light traveling through more atmosphere.

Dusk/dawn

Mid-day

Energy at the surface

1. Absorbed by earth

2. Reflected back to atmosphere

3. Absorbed by the clouds and gases in atmosphere.

Green house effect – is when energy is absorbed by water vapor, CO2, methane, and other gases in the air, causing a warm “blanket” to form in the atmosphere.

Temperature

Thermal energy – the total energy of motion in the molecules of a substance.

Temperature – is the average amount of energy of motion of each molecule of a substance, thus the measure of how hot or cold a substance is.

Thermometer – a thin glass tube with a bulb on one end that contains a liquid (colored alcohol)

---- temp-----

when a liquid is heated up it will expand! This expansion is restricted to going only two directions in a thermometer, UP or Down! When it rises it indicates more energy in the liquid molecules and causing the liquid to expand up. When heat (energy) is lost the molecules will come closer together taking up less space and indicating a lower temp.

Heat Transfer

3 types

1. radiation – the direct transfer of energy by electromagnetic waves.

2. Conduction – the direct transfer of heat from one substance to another substance that it is touching.

3. Convection – The transfer of heat by the movement of a fluid.

Pg. 51

radiation

eyr

Winds

Wind – is the horizontal movement of air from an area of high pressure to an area of lower pressure.

- pressure differences are caused by

an unequal heating of the atmosphere.

- cold dense air sinks and warm air

rises causing a movement of air (wind)

high pressure vs. low pressure.

Anemometer – measures wind speed.

Wind chill is the cooling of warm blooded mammals due to heat

loss from wind. Wind direction – Named (west wind) by the direction it is coming from. So, a west wind would be coming from the west and blowing toward the east.

Local wind – winds that blow over short distances. Ste. Gen to Cape or smaller, do to unequal heating of surface of Earth.

Sea breeze – wind blowing inland from the sea.

Earth heats up quicker less pressure than air over water

more pressure. Day time.

Land breeze – wind blowing out to sea from the land, due to opposite of sea breeze. Night time

Monsoons – sea and land breezes over a large region that change direction with the seasons.

Global winds – (created by unequal heating) winds that blow steadily from specific directions over long distances. The movement of air from the equator to the poles as a result of convection is a global wind. See pg 59.

Coriolis Effect – The way Earth’s rotation makes winds curve. http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/gifs/coriolis.mpg

Jet stream – A high level stream of fast moving air. At altitudes of 6 miles high and at

speeds of 180km to 350km.