15.2 Atmospheric Heating You are lying in a park with your eyes closed, and you feel the warmth of the sun on your face. Did you ever realize that it takes a little more than 8 minutes for the energy to travel to your face from a star 149,000,000 km away?
Weather Factors Sun’s energy travels to earth as Electromagnetic waves.
Weather Factors Scattering: Reflections of light in all directions. Why is the sky blue?
Radiation Sun on your face standing by campfire direct transfer of energy by electromagnetic waves through space.
Conduction Bare feet burned by hot sand direct transfer of heat from one substance to another through direct contact.
Convection Basement colder than upstairs transfer of heat by the movement of fluid or air. Hot air rises, cold air sinks. Transfer of energy by circulation.
Examples Cooking on the stove-pot on burner Hot air balloon rising Fireplace warming a room Curling iron on hair Blow dryer on hair Air from furnace heating the house
How is Earth heated? Light/heat from the sun RADIATES through the atmosphere, hits the Earth where it is absorbed. This heats the air above it by CONDUCTION. This heat rises up to the greenhouse gases where it is trapped, cools, sinks and heats at the surface again.-CONVECTION.
Weather Factors
Radiation Ever feel the heat of the sun on your face or the heat from standing by a campfire? That is radiation. It is the direct transfer of energy by electromagnetic waves.
Conduction Have you walked barefoot on the sand at the beach and the sand burned your feet? That is conduction. It is the direct transfer of heat from one substance to another.
Convection Have you ever come inside with wet shoes on and your mother told you to put them over the heating vent to dry? How does this dry them even though the actual furnace is in the attic? That is convection. The transfer of heat by the movement of fluid or air. Hot air rises, cold air sinks.
Bonfire Example Radiation keeps you away. Smoke and flame are carried away by convection. Ground beneath the fire gets hot by conduction.
How earth is heated. Light/heat from the sun radiates through the atmosphere, hits the Earth where it is absorbed. This heats the land and air above it by conduction. This heat rises up to the greenhouse gases where it is trapped, it cools, sinks and heats at the surface again.-Convection. Think about it: Why does 70 degrees in Spring feel colder than 70 degrees in Fall?
Energy from the sun is the driving force behind the water cycle, which contributes to create Earth’s weather. Radiation is transfer by electromagnetic waves. Thermal conduction is energy transfer by direct contact. Convection is energy transfer by circulation. The greenhouse effect is Earth’s natural heating process. Increasing levels of greenhouse gases could cause global warming.
Greenhouse Effect These gases absorb the heat and act as a “blanket” to keep Earth warm. Some greenhouse gases: water, methane, carbon dioxide.
Runaway Greenhouse Effect
Runaway Greenhouse Effect http://www.epa.gov/climatechange/kids/global_warming_version2.html
The Greenhouse Effect Global Warming gases (CO2 and water vapor) absorb thermal energy and radiate it back to Earth a process that reminds us of an actual greenhouse an increase in average global temperatures greenhouse gases in the atmosphere VS.
Global Warming Causes Natural: Volcanoes Solar flares Flatulence Cycle Orbit Snow Poop Cows Forest fires Methane release in the arctic tundra
Manmade Causes: Industry Deforestation Cars Fossil fuels Hairspray Wars Blow dryers Heat/AC Hot water Arms race Nuclear waste Coal burning Electricity Land fills Acid rain
Define and Design Draw, color, label and explain your own picture of the Greenhouse Effect.
Egg in bottle Fire warmed up air inside, molecules escaped before egg was put on top and when egg wobbled. When fire went out, temperature cooled, molecules condensed, changing air pressure. Since the pressure outside bottle was higher, the higher pressure tried to get in the bottle. Since the egg is squeezable, it got pushed into the bottle by the air.