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Understanding Climate: The Sun. The source of all energy in ecosystems is the Sun. The Sun Provides:. Heat and warmth Photosynthesis Wind Fossil fuels. The Sun has the largest affect on the Earth’s climate. http://www.youtube.com/watch?v=Cl4Pz1mwBao. Warming the Earth.
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The Sun Provides: • Heat and warmth • Photosynthesis • Wind • Fossil fuels
The Sun has the largestaffect on the Earth’s climate. http://www.youtube.com/watch?v=Cl4Pz1mwBao
Warming the Earth • The Sun does not warm all parts of the Earth the same. • This is because the Earth is round.
Sunlight comes down to Earth straight and gets concentrated. Sunlight comes down to Earth at an angle and gets spread out. See pg. 309
Yearly Cycles • The climate in an area is also affected by seasons. • Seasons are caused by the tiltof the Earth.
Summer Winter
Reflected by atmosphere Reflected by clouds Reflected by Earth’s surface Absorbed by atmosphere Absorbed by land and water
Conservation of Energy Energy cannot be created or destroyed, only transferred from one form to another. • Radiated light energy from the sun: • reflected • OR converted as it is absorbed. Activity Pause Demonstrate heating up of soil/rock sample using a heat lamp (GIZMO)
GIZMO: Activity • Heat AbsorptionShine a powerful flashlight on a variety of materials, and measure how quickly each material heats up. See how the light angle, light color, type of material, and material color affect heating. A glass cover can be added to simulate a greenhouse. http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=655&ClassID=1734230
Review GIZMO • Black vs. white brick • Wood vs. Metal • Water vs. Black brick
Solar Radiation • Albedo Effect – the percentage of light that an object reflects
Heating the PLANET • Every object has THERMAL energy. • Energy due to the motion of PARTICLES • Transfer or THERMAL ENERGY from hotter object to colder is known as HEAT • Radiation • Conduction • Convection
Energy Transfer • Convection • transfer of heat by the movement of particles from one part of a fluid to another • Conduction • transfer of heat by the collisions of particles • Radiation • transfer of energy by means of waves
Convection! a hot parking lot can heat the air above it and this heating causes the air to rise.
Heat escapes to space (heat sink) Transferred through the atm by air currents (convection) Sun’s Radiation Heat from water is transferred to the atm by conduction (atm takes heat from water by convection) Daytime, heat from ground is transferred to atm and water by conduction (atm and water take heat from the ground by convection) soil …. Collision of molecules (conduction) Heat is transferred through water by convection
Uneven heating of atmosphere – creates winds Atmosphere MOTION
Wind disperse ENERGY Through the Atmosphere wind Air cools And sinks Warm air Rises and expands wind Air movement transfers thermal energy around the world from warmer to cooler areas Wind moves ocean currents brings warm waters to Northern countries (Gulf Stream)
ATMOSPHERE MOTION: Prevailing Winds ….All Around the World • Prevailing winds are caused by a combination of convection currents formed by pressure differences and Earth’s eastward rotation.
Intense radiation at theequator warms the air Air cools as itrises, moisturecondenses andfalls as rain Warm air rises, collecting moisture Lots of rain in the tropics!
some of the risingair flows south some of the risingair flows north Rising air is now dry… Dry air descendsat around 30º N …and at around 30º S Deserts Deserts The descending air flows N and S
L L Generally, Highs and Lows form around the four areas listed. Equator = L 30o lat = H 60o lat = L N. Pole = H H H
Notice: Winds are named by the direction they originate from, not where they are going.
Energy Transferred in the Oceans • Winds create currents of water • Cold water is dense sinks pushes warm water up …convection…… • salt water is denser than fresh water Thermohalline circulation – a three-dimensional pattern of ocean circulation driven by wind, heat, and salinity that is an important component of the ocean-atmosphere climate system
Questions • How is conduction different from convection? (k/u) • Compare the processes by which heat is transferred in the atmosphere and in the oceans. (k/u) • How is the energy that Earth absorbs different from the energy that Earth emits? (k/u) • The table below shows what percentage of thermal energy is absorbed by different parts of Earth’s climate system. Explain what effect the relative sizes of the oceans and atmosphere have on their role in storing and transferring energy. (APP) • If Earth has had a balanced energy budget for billion of years, why do climatologists think that the energy budget might be changing now? (T/I)