Composition of the Atmosphere Atmosphere -layer of gases that surrounds a planet or moon. Composed of: 78% Nitrogen Dead plants & Animals Volcanoes 21% Oxygen Trees & Plants 1% Other Gases (Argon, CO 2, water vapor & other gases)
Air pressure-Gravity pulls gas molecules in the atmosphere toward the Earth’s surface. Air pressure is how much the air above you weighs. It measures how hard air molecules are pushed on a surface. Composition of the Atmosphere
As altitude increases, air pressure and barometric reading decreases. The higher you go, the lower the air pressure gets. Air Pressure High Pressure Low Pressure
Barometer – instrument that measures air pressure Air Pressure Air Pressure Facts Centers of storms low air pressure Around storms higher air pressure High air pressure = good weather Low air pressure = bad weather Keeping track of changing air pressure important for: forecasting the weather.
As altitude increases, air temperature decreases. Lower parts of the atmosphere are warmer because they contain a high percentage of gases that absorb solar energy. Air Temperature
Layers of the Atmosphere There are 4 main layers of the Atmosphere: 4) Thermosphere Ionosphere 3) Mesosphere 2) Stratosphere Ozone Layer 1)Troposphere
Thermosphere Air Temp. & Pressure Changes Important Features Temperature increases Pressure decreases Uppermost layer of atmosphere Temperature is high because nitrogen & oxygen absorb energy from the sun Lowermost part contains Ionosphere
Ionosphere Between the Thermosphere & Mesosphere Auroras occur here which are curtains & ribbons of shimmering colored lights They form when charged particles from the sun collide with ions
Mesosphere Air Temp. & Pressure Changes Important Features Temperature decreases Pressure decreases The coldest layer Protects earth from meteorites Auroras occur in the Ionosphere.
Stratosphere Air Temp. & Pressure Changes Important Features Temperature increases Pressure decreases Gases are layered & do not mix Temp. increases because of the presence of ozone gas. Ozone layer- is important for life on Earth because it absorbs energy from the sun including harmful ultraviolet energy. Jet stream – moves weather
Troposphere Air Temp. & Pressure Changes Important Features Temperature decreases Pressure decreases Layer of the atmosphere we live in Contains 90% of the gases Weather conditions take place here Ex. rain & wind The densest layer that contains- Water vapor, Carbon dioxide, Pollution, Living things
Recap!!! What is the atmosphere composed of? Gases (78% Nitrogen, 21% Oxygen, 1% Other) Describe what air pressure is? Air pressure is how much the air above you weighs. It is the gas molecules gravity pulls from the atmosphere towards Earth. What is the difference between air pressure in the atmosphere and near Earth? The closer to Earth, the higher the air pressure. In the atmosphere, air pressure is lower.
Recap!!! What are the four main layers of the atmosphere? Troposphere, Stratosphere, Mesosphere, Thermosphere Where is the Ozone layer found? Stratosphere Which two layers contain the Ionosphere? Mesosphere and Thermosphere Which layer do we live in? Troposphere
Radiation DefinitionExamples The transfer of energy as electromagnetic waves. Open flames from a fire radiating heat to toast a marshmallow.
Types of Energy Transfer DefinitionExamples Energy is transferred by contact. When a warm object touches a cold object, heat moves from the warm object to the cold one. Burning your hand by touching a steaming hot pot. Conduction
Types of Energy Transfer DefinitionExamples Energy is transferred by the circulation or movement of gas or liquid. Water (liquid) boiling in a pot Convection
Experiment What do you think is going to happen when hot water and cold water are mixed together?
Atmospheric Heating Convection Current – the circular movement of warm and cold air Why does warm air rises & cold air sink? Warm air is less dense, so it rises. Cold air is more dense, so it sinks.
1)Gases in the atmosphere absorb heat energy coming from Earth 2)They then radiate it back to Earth’s surface The most common greenhouse gases are: Water vapor Carbon Dioxide Methane Nitrous oxide Ozone Greenhouse Effect :
What do you know about global warming? Four Corners I know everything, I’m an expert! I know a lot, but want to know more! I know a little, just what I’ve heard! I know nothing, please feed me knowledge!
Global Warming – an increase in temperatures all over the world. Many scientists believe this is caused by greenhouse gases. Greenhouse gases trap heat in the atmosphere Global warming affects weather and climate. Global Warming
Recap!!! A person is camping outside. The person toasts a marshmallow by holding it above the flames of the fire. How is heat transferred? Radiation When you touch the sidewalk on a hot, sunny day. How is heat energy transferred from the sidewalk to you? Conduction You decide to surprise your parents and iron your own clothes one day. How is heat energy transferred from the iron to your clothes? Conduction
Recap!!! You boil a pot of water to make pasta. As the water heats up, its density decreases and it rises. The cooler water then sinks until it begins to heat up…and so on. How is heat transferred? Convection You made delicious pancakes for your friends last weekend. How was heat transferred? Conduction A bonfire is built on the beach of the Jersey Shore to warm people up at night. How is heat transferred? Radiation
Recap!!! You have left over Chinese food from the night before and want to heat it up in the microwave? How is heat transferred? What is the circular movement of warm and cold air? Convection Current Radiation Why does warm air rise and cold air sink? Warm air is less dense and cold air is more dense
Recap!!! What is an increase in temperatures all over the world? What causes global warming? Greenhouse gases trapped in the atmosphere Global Warming What two things get affected by global warming? Weather and Temperature
Recap!!! How is global warming and the greenhouse effect related? Greenhouse gases absorb heat energy and trap heat in the atmosphere. This is causing the Earth to become even warmer. This leads to global warming, which is the increase in temperatures all over the world.
DO NOW- Tell a friend what these photos have in common.
Wind Wind – moving air caused by differences in air pressure. Air moves from areas of high pressure to areas of low pressure. The greater the pressure difference, the faster & stronger the wind blows.
Jet Streams - narrow belts of high-speed winds that blow in the upper troposphere and lower stratosphere Wind They blow from west to east all the way around the Earth
Why do global winds curve? The Coriolis Effect: The deflection, or curving, of moving objects from a straight path because of Earth’s rotation Global Winds– winds that circle the globe and move in curved directions.
Local Winds Local winds – winds that generally move over short distances and can blow from any direction. They are affected by: 1)Temperatures 2)Geographic features
Sea and land breezes- local winds affected by temperature Examples of Local Winds
Mountain and valley breezes- are examples of local winds caused by an area’s geography. Examples of Local Winds
Recap!!! Differences in cause wind to move? High, Low The greater the pressure differences in an area, winds blow faster & stronger or slower & weaker? Faster & Stronger Air moves from areas of pressure to areas of pressure? Air Pressure
Recap!!! What two layers of the atmosphere does the Jet Stream blow? West to East Which way does the Jet Stream blow? Upper Troposphere & Lower Stratosphere What are winds that circle the globe and move in curved directions? Global Winds
Recap!!! The deflection, or curving of moving objects from a straight path because of Earth’s rotation. This causes global winds to move in a curved direction. What are local winds? Local winds travel short distances and can blow from any direction. Describe the Coriolis Effect and the affect that is has on the entire Earth.
Recap!!! What are the two things that affect local winds? Mountain and Valley Breezes What is an example of local wind that is affected by temperature? Sea and land breezes What is an example of local wind that affects an area by geography? Temperature & Geographic Features