Standard 5.b -- Students know the relationship between the rotation of Earth and the circular motions of ocean currents and air in pressure centers. Why We Should Care: It helps to explain how the weather moves across the sky It explains why we have the climate that we do here in California

What is a fluid? A fluid is a substance that conforms to the container that it is in. Is water a fluid? Is a brick a fluid? Is air a fluid?

Fluids (liquids and gases) are easily influenced by other things. Air moves out of the way when you walk through it Air and water both behave in similar ways because they are fluids. Water flows down the slightest hill because of gravity

What fluids are present on or above the surface of the Earth? The ocean (water) The atmosphere (air) They are easily influenced by other forces

Heat from the sun warms air enough that it rises…but it is not the same amount at every place on the globe. As you move north or south, the same amount of sun gets spread out over a greater area, so it is not as warm. 1 st Factor that Affects Air Currents -- Energy from the Sun

Warm air at the equator rises until it hits the stratosphere (upper layer of atmosphere) It then spreads out and cools. Eventually, it cools enough to sink and return to Earth This process creates a convection current

This convection current is called a Hadley cell and it looks like this in its simplest form. But here’s the problem…the Earth is spinning. 2 nd Factor that Affects Air Currents – Spin of the Earth Each current of air close to the Earth’s surface deflects (turns) because the Earth is spinning. This is called the Coriolis effect.

This process makes three separate cells in each of the hemispheres. In Northern Hemisphere, rotation is clockwise (right) In Southern Hemisphere, rotation is counterclockwise (left)

Wind TypeLatitudeDirection of Air Current Trade Winds0 – 30 degreesblows west Wind TypeLatitudeDirection of Air Current Trade Winds0 – 30 degreesblows west Prevailing Westerlies30 – 60 degreesblows east Wind TypeLatitudeDirection of Air Current Trade Winds0 – 30 degreesblows west Prevailing Westerlies30 – 60 degreesblows east Polar Easterlies60 – 90 degreesblows west

Surface Currents Surface currents are movements of water that flow in a horizontal direction on the ocean’s surface. The surface currents develop from friction between the ocean and the wind that blows across the surface. air flow

Below are the surface currents throughout the worlds’ oceans. The direction of the surface currents correspond to the winds that blow above the water westerlies trades

Gyres Numerous surface currents work together to form large circular patterns called gyres. The gyres rotate in opposite directions because of the different air current zones that drive the surface currents

These surface currents are ultimately responsible for distributing heat around the globe. They move warm water from the equator toward the poles.

Why We Should Care: These currents regulate the world temperatures…if they shut down, we could be thrown into another ice age Standard 5.d -- Students know properties of ocean water, such as temperature and salinity, can be used to explain the layered structure of the oceans, the generation of horizontal and vertical ocean currents, and the geographic distribution of marine organisms.

Density currents are different from surface currents because they move vertically rather than horizontally. They are driven by differences in density of ocean water.

Density: how much mass a substance has in a certain volume of space Mass: how heavy the molecules are Volume: how much space the molecules take up Examples: Water has a density of 1.0 g/cm 3 while lead has a density of 11.3 g/cm 3. More dense more molecules in a specific space, tends to sink Less dense less molecules in a specific space, tends to rise

Factors that Affect the Density of Ocean Water 1.Temperature When water heats up, the molecules move faster and take up more space. + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + + H H - O + Cold Water: tightly packed more dense sinks Warm Water: spacious less dense rises

Because the Earth is tilted, the sun’s rays hit the Earth differently, called differential heating. This causes the density of sea water to vary with location. Water at the poles: least direct sun coolest more dense Water at the Equator: most direct sun warmest less dense

2. Salinity When salt gets dissolved in water, more molecules are crammed into the same amount of space + H H - O + + H H - O + + H H - O + + H H - O + Cl - Na + Cl - Na + + H H - O + + H H - O + + H H - O + + H H - O + Salt Water: tightly packed more dense sinks Fresh Water: spacious less dense rises

Sea salt is actually a mixture of many different substances These substances come from two sources: 1.Weathered rocks – runoff breaks down rock and carries the sediments to the ocean 2.Volcanic gases – eruptions spew gases in the air which eventually land in the ocean

Why is the salinity so low at the Equator? Lots of rain which dilutes the ocean Why is the salinity so high at 30° N and S? Lots of sun (deserts) evaporates ocean water making it salty

Density currents create the Ocean Conveyor Belt. It is a large current system that runs throughout the world. It consists of: Warm surface flow (at the ocean surface) Cold subsurface flow (at the ocean floor)

The circulation current sinks in the North Atlantic because of the cold temperature of the high latitudes (high density water) The current rises in the Indian Ocean because of the excessive rain and in the Pacific Ocean because the water is slightly warmer (low density water)

The warm surface flow gives much of Europe and North America a warm climate because of warm water brought northward. As the Earth warms, polar ice will melt making the water less dense, slowing down the sinking process and shutting down the entire belt. Much of the Northern Hemisphere would be thrown into an ice age. Ice Age if Current shuts down

NamePercentTempSalinityDensity Surface2%WarmLow Transition18%Medium Deep80%ColdHigh Ocean Layers NamePercentTempSalinityDensity Surface2%WarmLow Transition18%Medium Deep NamePercentTempSalinityDensity Surface Transition Deep NamePercentTempSalinityDensity Surface2%WarmLow Transition Deep

NameNutrientsOrganisms Surface Transition Deep NameNutrientsOrganisms SurfacePoorPhytoplankton (need light) Zooplankton (eat phytoplankton) TransitionMediumLarger marine life DeepRichDecomposing organisms NameNutrientsOrganisms SurfacePoorPhytoplankton (need light) Zooplankton (eat phytoplankton) Transition Deep NameNutrientsOrganisms SurfacePoorPhytoplankton (need light) Zooplankton (eat phytoplankton) TransitionMediumLarger marine life Deep

Upwelling is a process that brings nutrients from the bottom of the ocean to the surface. Wind blows water at the surface driving it away. This allows lower layers to move upward bringing nutrients to the surface. Upwelling

Standard 7.b -- Students know the global carbon cycle: the different physical and chemical forms of carbon in the atmosphere, oceans, biomass, fossil fuels, and the movement of carbon among these reservoirs. Why We Should Care: We are active participants in the cycle There is debate about how humans affect the cycle and ultimately the global climate

Carbon’s flexibility allows it to form many different types of compounds, which allows carbon to travel through the different parts of the environment Atmosphere: The air above the Earth’s crust Rocks: The Earth’s crust Fossil Fuels: Substances made of once-living materials Oceans: The water on the Earth’s crust Biomass: All living organisms on the planet

Carbon in Rocks Primary Form: –Calcium carbonate (CaCO 3 ) % of world-wide Carbon storage: –99.9% Formed by: –Sedimentation from the ocean Recycled through: –Volcanic eruptions to make CO 2 in the atmosphere

Carbon in the Atmosphere Primary Form: –Carbon dioxide (CO 2 ) % of world-wide Carbon storage : –0.001% Made by: –Volcanic eruptions from rock –Diffusion from the ocean –Respiration from biomass (living things) –Combustion of fossil fuels Recycled through: –Precipitation to make H 2 CO 3 & CO 3 in the ocean –Photosynthesis to make C 6 H 12 O 6 in biomass

Carbon in the Ocean Primary Forms: –Carbonic acid (H 2 CO 3 ) % of world-wide Carbon storage: –0.08% Made by: –Precipitation from the CO 2 in the atmosphere Recycled through: –Diffusion to make CO 2 in the atmosphere –Sedimentation to make CaCO 3 in rocks

Carbon as Fossil Fuels Primary Forms: –Carbon/coal (C) and methane (CH 4 ) % of world-wide Carbon storage: –0.009% Formed by: –Decomposition of biomass (living things) Recycled through: –Combustion to make CO 2 in the atmosphere

Carbon in the Biomass Primary Form: –Glucose (C 6 H 12 O 6 ) % of world-wide Carbon storage: –0.004% Formed by: –Photosynthesis of CO 2 Recycled through: –Respiration to make CO 2 in atmosphere –Decomposition to make CH 4 and C in fossil fuels

Carbon Cycle Processes Respiration: using O 2 gas to break down C 6 H 12 O 6 and releasing CO 2. This is done by animals The opposite is called photosynthesis C 6 H 12 O 6 + O 2 air CO 2 atmosphere Converts sugar to carbon dioxide Respiration

Carbon Cycle Processes Photosynthesis: Plants breathe in CO 2 gas and with sunlight make C 6 H 12 O 6 and releasing O 2 The opposite is called respiration C 6 H 12 O 6 + O 2 air CO 2 atmosphere Converts carbon dioxide to sugar Photosynthesis

Atmosphere Form = CO 2 Ocean Form = H 2 CO 3, CO 3 Rock Form = CaCO 3 Fossil Fuels Form = CH 4, C Biomass Form = C 6 H 12 O 6, C 6 H 10 O 5 Combustion Volcanic Eruption Sedimentation Decomposition Photosynthesis Precipitation Diffusion Respiration

There are two sources of energy that drive the carbon cycle…. The sun is an external source of energy. It enters the carbon cycle when plants experience photosynthesis. Magma from the Earth’s interior is an internal source of energy. It enters the carbon cycle when underground rock melts.

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