NOTES HEAT TRANSFER Movement of thermal energy from
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NOTES: HEAT TRANSFER Movement of thermal energy from one place to another is called HEAT THREE METHODS of heat transfer occur in our atmosphere: RADIATION CONVECTION CONDUCTION
RADIATION is heat transfer by rays of energy on the ELECTROMAGNETIC SPECTRUM. . AT) (HE
CONVECTION is heat transfer by the motion of hot and cold fluids (either gas or liquid).
CONVECTION: Hot air is less dense and rises. Cold air is more dense and sinks. (Circular. . just like in the mantle!)
CONDUCTION is heat transfer by direct contact between two objects.
CONVECTION: Heat transfer through the motion of gas or liquid. CONDUCTION: Heat transfer through direct contact (touch it and you get burned). RADIATION: Heat transfer through space in the form of waves. You can feel it with NO direct contact (like when you feel sunlight).
HOW to COOK an EGG
The air in the troposphere is warmed mainly through RADIATION, and cycled by CONVECTION. (1)The sun shines on the ground, which absorbs the energy and heats up with a highfrequency wave. (2) The ground reflects heat back up with a lower frequency wave. (3) This wave does not have enough "power" to escape the atmosphere, so it gets trapped and warms the air. SUN: atmosphere LAND:
Energy from the sun is transferred as ____ Some is absorbed by the THERMOSPHERE and some by the OZONE LAYER. Some warms the ground. Air touching the ground is heated by _____ Warm air moves around because of _____
"GLOBAL WARMING / Part I" Holes in the Ozone Layer let in more harmful radiation, which would never reflect back out of the atmosphere. . .
"GLOBAL WARMING / Part II" Greenhouse Gases from pollution, etc. would keep the heat trapped in the atmosphere that came in those holes like a blanket. . . Greenhouse Gases are Water Vapor, Carbon Dioxide, spray-can propellants, gases from living things
"Greenhouse Gases" (carbon dioxide, methane, water vapor) would keep the heat trapped in the atmosphere like a blanket. . . TOGETHER create a condition that causes Global Warming. Greenhouse Gases are Water Vapor, Carbon Dioxide, spray-can propellants, gases from living things
Things that affect how the ground absorbs radiation include: Reflective or shiny surfaces Colors Textures "ALBEDO"
Other things that can affect absorbtion of radiation include: Angle of incidence (the angle that the sun is shining on something) Specific Heat Capacity, which is how much energy it takes to raise the temperature of a substance by one degree. (It takes a lot more energy for water to heat up and cool down, compared to rocks and land surfaces)
Two things we observe in the atmosphere when heat is transferred, are CLOUDS and WIND!
CFU Questions (Check for Understanding!)
SPECIFIC HEAT QUESTION #1: You're forging a sculpture in Mr. Wilson's engineering class. Which material is easier to melt: luminum or lead?
SPECIFIC HEAT QUESTION #2: On a hot sunny day at the beach, why does the sand get really hot, but the water doesn't?
Why do HOLES IN THE OZONE and the GREENHOUSE GASES work together to make a big problem for our atmosphere?
When you get an X-ray, the doctor covers you with a lead vest. When you listen to the radio, you don't wear lead. WHY?
Wind blows in different directions during the day than at night. WHY?