APES

Unit 4: Earth Systems 🌎

14.1 Plate Tectonics tectonic plates

Objectives, Essential Knowledge, & Skills

This section details the objectives, essential knowledge, and skills related to plate tectonics. Specific details were not provided in the transcript.

Earth's Structure

• Core: Dense mass of solid nickel, iron, and radioactive elements that release massive amounts of heat.

• Mantle: Liquid layer of magma surrounding the core, kept liquid by intense heat from the core.

• Asthenosphere: Solid, flexible outer layer of the mantle, beneath the lithosphere.

• Lithosphere: Thin, brittle layer of rock floating on top of the mantle (broken up into tectonic plates).

• Crust: Very outer layer of the lithosphere; Earth's surface.

Plate Boundaries

Convection Cycles

magma→heatrise→Divergentplates apart→coolsinkmagmaheat​riseDivergent​platesapartcool​sink

Magma, heated by Earth's core, rises (Divergent). Rising magma cools and expands, forcing oceanic plates apart. This creates mid-ocean ridges, volcanoes, spreading zones, or seafloor spreading. Magma cools, and solidifies into new magma, forcing oceanic plates into continental lithosphere (subduction zone). Sinking oceanic plate melts back into magma. This also forces magma up, creating narrow, coastal mountains (Andes) & volcanoes on land.

Convergent Boundary = Subduction Zone

• Oceanic-Oceanic: One oceanic plate subducts beneath another plate and melts back into magma, forming island arcs and trenches.

• Oceanic-Continental: Dense oceanic plate subducts beneath continental plate, forcing magma up to the lithosphere surface (mountains and volcanoes). Example: Andes Mountains.

• Continental-Continental: One continental plate subducts underneath the other, forcing surface crust upward (mountains). Example: Himalayas.

Tectonic Map Predictions

• Ring of Fire: Pattern of volcanoes all around the Pacific plate.

• Offshore island arcs (Japan): Likely locations of volcanoes.

• Transform faults: Likely locations of earthquakes.

• Hotspots: Areas of especially hot magma rising up to the lithosphere. Examples: Mid-ocean islands (Iceland, Hawaii).

Practice FRQ

4.1 Explain how subduction leads to volcanic activity.

4.2 Design an investigation to measure the effect that climate has on soil formation. Identify the independent variable and the dependent variable in your experiment.

4.2 Soil Formation & Erosion 🌱

Objectives, Essential Knowledge, and Skills

This section outlines the objectives, essential knowledge and skills related to soil formation and erosion. Specific details were not provided in the transcript.

What is Soil?

• Sand, silt, clay: The geologic components.

• Humus: The main organic part of soil (broken-down plant biomass like roots, leaves, dead animals, waste, etc.).

Soil Functions

• Anchors: Roots of plants provide water, shelter, and nutrients (N, P, K, Mg) for growth.

• Filters: Traps pollutants in pore spaces. Clean water enters groundwater and aquifers.

• Nutrients: Provides nutrients like ammonium, phosphates, and nitrates.

• Habitat: Provides habitat for organisms like earthworms, fungi, bacteria, moles, and slugs.

• Recycling: Home to decomposers that break down dead organic matter and return nutrients to the soil.

Weathering & Erosion

• Weathering: Breakdown of rocks into smaller pieces.

  • Physical: Wind, rain, freezing/thawing of ice.

  • Biological: Roots of trees crack rocks.

  • Chemical: Acid rain, acids from moss/lichen.

• Erosion: Transport of weathered rock fragments by wind and rain. Carried to a new location and deposited (deposition).

Effects on Soil Formation

Soil Horizons

• O-Horizon: Layer of organic matter (plant roots, dead leaves, animal waste, etc.) on top of soil. Provides nutrients and limits water loss to evaporation.

• A-Horizon (Topsoil): Layer of humus (decomposed organic matter) and minerals from parent material. Most biological activity.

• B-Horizon (Subsoil): Lighter layer below topsoil, mostly made of minerals with little to no organic matter. Contains some nutrients.

• C-Horizon: Least weathered soil closest to the parent material, sometimes called bedrock.

Soil Degradation

• Loss of topsoil: Tilling (turning soil for agriculture) and loss of vegetation disturb soil and make it more easily eroded by wind and rain. Dries out soil, removes nutrients, and soil organisms that recycle nutrients.

• Nutrient depletion: Repeatedly growing crops on the same soil removes key nutrients (N, P, K, Na, Mg). Dry soil erodes more easily over time and supports less plant growth.

• Compaction: Compression of soil by machines (tractors, bulldozers, etc.), grazing livestock, and humans reduces the ability to hold moisture. Reduces the ability to grow future crops.

4.2 Practice FRQ

Design an investigation to measure the effect that climate has on soil formation. Identify the independent variable and dependent variable in your experiment.

4.3 Soil Composition & Properties 🧪

Objectives, Essential Knowledge, and Skills

This section lists the objectives, essential knowledge and skills related to soil composition and properties. Specific details were not provided in the transcript.

Soil Particle Size, Texture, and Porosity

The geologic (rock) portion of soil is made up of three particles (biggest to smallest): sand > silt > clay.

• Soil texture: The percentage of sand, silt, and clay in a soil. Always adds up to 100%. Example: Loam = 40-40-20 (sand, silt, clay).

• Porosity: The amount of pore space a soil has. More sand = more porous/higher porosity (easier for water and air to enter). More clay = less porous/less porosity (harder for water and air to enter).

Soil Texture Chart

A visual soil texture chart was referenced but not included in the transcript. Instructions for using the chart were given.

Effect on Soil Fertility

• Sandy soil (too permeable) drains water too quickly for roots and dries out.

• Clay-heavy soil doesn't let water drain to roots, or waterlogs (suffocating them).

• Ideal soil for most plant growth is loam, which balances porosity/drainage with water-holding capacity.

Porosity, Permeability, and Water Holding Capacity

• Porosity: Pore space within a soil. More sand = more porous.

• Permeability: How easily water drains through a soil. More porous/higher porosity = more permeable/higher permeability. Positive relationship between porosity and permeability.

• Water Holding Capacity: How well water is retained or held by a soil. More porous/permeable = lower water holding capacity. Inverse relationship between porosity/permeability and water holding capacity.

Soil Fertility

Factors that increase soil nutrients:

• Organic matter (releases nutrients)

• Humus (holds and releases nutrients)

• Compost/humus/organic matter

• Decomposer activity (recycles nutrients)

• Clay content

• Clay (negative charge binds positive nutrients)

• Root structure, especially natives

• Bases (Calcium carbonate - limestone)

Factors that increase water holding capacity:

• Aerated soil (biological activity)

• Humus (holds and releases nutrients)

• Clay content

• Clay (negative charge binds positive nutrients)

• Root structure, especially natives

• Bases (Calcium carbonate - limestone)

Factors that decrease soil nutrients:

• Compacted soil (machines, cows)

• Acids leach positive charge nutrients

• Sand

• Excessive rain/irrigation leaches nutrients

• Root loss

• Excessive farming depletes nutrients

• Topsoil erosion

Factors that decrease water holding capacity:

• Compacted soil (machines, cows)

• Topsoil erosion

• Sand

• Excessive rain/irrigation leaches nutrients

• Root loss

Characteristics and Tests of Soil Quality

4.3 Practice FRQ

Identify and describe one test that can be conducted on a soil sample. Explain how the results of the test could allow you to give advice to a farmer trying to grow crops in the soil.

4.4 Atmosphere ☁

Objectives, Essential Knowledge, and Skills

This section details the objectives, essential knowledge, and skills related to the atmosphere. Specific details were not provided in the transcript.

Gases of Earth's Atmosphere

Characteristics of Layers

• Exosphere: Outermost layer where the atmosphere merges with space.

• Thermosphere: Hottest temperature; absorbs harmful X-rays & UV radiation; charged gas molecules glow under intense solar radiation producing northern lights (aurora borealis).

• Mesosphere: Middle layer (60-80 km); even less dense.

• Stratosphere: Second layer (16-60 km); less dense; thickest O₃ layer absorbs UV-B & UV-C rays.

• Troposphere: Layer where weather occurs (0-16 km); most dense; most of the atmosphere's gas molecules are found here; ozone (O₃) in the troposphere is harmful to humans.

Temperature Gradient

Layers of Earth's atmosphere are based on where temperature gradients change with distance from Earth's surface.

• Thermosphere: Temperature increases due to absorption of highly energetic solar radiation. Hottest place on Earth (3,100°F).

• Mesosphere: Temperature decreases because density decreases, leaving fewer molecules to absorb sun. Coldest place on Earth (-150°F).

• Stratosphere: Temperature increases because the top layer of the stratosphere absorbs high-energy UV radiation.

Atmospheric Science Lecture Notes

🌎 Troposphere Temperature Profile

The troposphere exhibits an inverse relationship between temperature and altitude. This is because the Earth's surface is warmed by UV rays (like a pool surface). As air gets further from this warmth, the temperature decreases.

💨 Global Wind Patterns 🌍

Atmospheric circulation is driven by three key factors:

1. Energy from sunlight

2. Density properties of air

3. Rotation of the Earth (Coriolis effect)

Here's a breakdown of air properties and their role in circulation:

1. More sunlight at the equator warms the air.

2. Warm air holds more moisture than cold air.

3. Warm air rises, cools, and expands.

4. Cooling, expanding air spreads out.

5. Cool, dry air sinks back down to Earth.

At 30° N & S:

• Rising air expands and cools.

• Water vapor condenses into rain.

• Cool air can't hold as much water vapor.

• Deserts form due to lack of moisture.

At 0°:

• Low pressure due to rising air.

At 30°:

• High pressure due to sinking air.

Coriolis Effect: Deflection of objects traveling through the atmosphere due to the Earth's spin.

• Wind between 0-30° moves from East to West because the Earth spins West to East.

• Wind between 30-60° moves West to East because the Earth spins faster at 30° than at 60°.

💦 Watersheds 🏞

• Determined by slope; ridges of land divide watersheds (different runoff directions).

• Vegetation, soil composition, and slope impact drainage.

• More vegetation = more infiltration & groundwater recharge.

• Greater slope = faster velocity of runoff & more soil erosion.

• Soil permeability determines runoff vs. infiltration rates.

• Human activities impact water quality (e.g., agriculture, clearcutting, urbanization, dams, mining).

Chesapeake Bay Watershed: A six-state region draining into the Chesapeake Bay. The mix of fresh and saltwater, plus nutrients in sediment, makes estuary habitats highly productive.

Ecosystem Services Provided by Estuaries & Wetlands:

• Tourism revenue

• Water filtration

• Habitats for food sources (fish & crabs)

• Storm protection

Human Impacts on Chesapeake Bay:

• Nutrient pollution (N & P) leads to eutrophication:

  • Algae blooms decrease sunlight, killing plants below the surface.

  • Bacteria use up O₂ for decomposition, causing hypoxia (low O₂).

• Sources of N & P:

  • Sewage treatment plants

  • Animal waste from CAFOs

  • Synthetic fertilizers

• Other major pollutants: endocrine disruptors and sediment pollution. Sediment increases turbidity (reduced photosynthesis) and covers over streambed habitats.

☀ Solar Radiation & Earth's Seasons 🌞

Insolation: The amount of solar radiation (energy from the sun's rays) reaching an area. Measured in Watts/m²/s.

Solar Intensity Depends On:

• Angle: How directly rays strike the Earth's surface.

• The amount of atmosphere the sun's rays pass through.

The Earth's orbit around the sun and its tilt on its axis change the angle of the sun's rays, causing variations in:

• Insolation

• Length of day

• Seasons

June & December Solstices: The N or S hemisphere is maximally tilted towards the sun (summer/winter).

March & September Equinoxes: N & S hemispheres equally facing the sun.

Albedo: The proportion of light reflected by a surface.

• Higher albedo surfaces reflect more light and absorb less (ice/snow).

• Lower albedo surfaces reflect less light and absorb more (water).

Surface Temperature is Affected by Albedo: When sunlight is absorbed, it gives off infrared radiation (heat). Areas with lower albedo absorb more sunlight (heat). Examples include urban heat islands and polar regions.

🗺 Earth's Geography & Climate 🌎

Climate is largely determined by insolation (latitude, angle of insolation, and atmosphere).

• Higher latitudes receive less insolation: cooler, less precipitation (especially at 30°).

• Equator receives most intense insolation: higher temperature, air rises, high precipitation.

Geography also plays a role:

• Mountains: Disrupt wind and produce a rain shadow effect.

• Oceans: Moderate temperature and add moisture to the air.

Rain Shadow Effect: Warm, moist air from the ocean hits the windward side of a mountain, rises, cools (condensing water vapor and causing rain). Lush, green vegetation. Dry air descends down the leeward side of the mountain, warming as it sinks, leading to arid (dry) desert conditions.

🌊 El Niño & La Niña 🌧

Global Ocean Surface Currents: Driven by global wind patterns. Gyres: Large ocean circulation patterns. Upwelling Zones: Areas where winds blow warm surface water away from a landmass, drawing up colder, deeper water.

Thermohaline Circulation: Warm water from the Gulf of Mexico moves toward the North Pole. Connects all of the world's oceans, mixing salt, nutrients, and temperature.

El Niño Southern Oscillation (ENSO): A pattern of shifting atmospheric pressure and ocean currents in the Pacific Ocean between South America and Australia/Southeast Asia. Oscillates between El Niño (warmer, rainier) and La Niña (cooler, drier) conditions along the coast of South America.

Normal Year:

• Trade winds push equatorial currents E to W.

• Westerlies push mid-latitude currents W to E.

• Upwelling off the coast of South America (cool temperatures + good fisheries).

El Niño:

• Trade winds weaken or reverse.

• Warm water moves east.

• Suppressed upwelling off the coast of South America (damaging to fisheries).

• Warmer and rainier than normal in South America.

• Cooler, drier conditions in Australia & SE Asia.

La Niña:

• Stronger than normal trade winds.

• Stronger upwelling off the coast of South America (better fisheries).

• Cooler, drier weather in South America.

• Rainier, warmer in Australia & SE Asia.
  
  Chapter 11: Geology and Nonrenewable Mineral Resources

  🌎 Tectonic Plates and Geological Hazards 🌍

  • Tectonic plates: Massive, solid plates forming the lithosphere, moving slowly across the Earth's surface. Their movement creates mountains, trenches, earthquakes, and volcanoes. Think of them like pieces of a gigantic jigsaw puzzle, constantly rearranging the continents and ocean basins over millions of years.

  • Plate boundaries: Locations where plates interact, often resulting in geological hazards.

  • Earthquakes: Release of energy accumulated along faults. Can cause tsunamis (underwater earthquakes).

  • Volcanoes: Often form along plate boundaries; eruptions can be highly destructive.

  • Weathering: Physical, chemical, and biological processes breaking down rocks and minerals.

  🪨 The Rock Cycle 🔄

  • Rocks: Large, natural, continuous parts of the Earth's crust. Three major types:

    • Igneous rocks: Formed from cooled magma or lava.

    • Sedimentary rocks: Formed from compressed sediments.

    • Metamorphic rocks: Formed when existing rocks are subjected to high temperatures or pressures.

  • Rock cycle: The continuous process of rocks changing from one type to another through physical and chemical processes.

  💎 Mineral Resources and Extraction ⛏

  • Mineral resources: Naturally occurring materials used for human purposes (metals, fossil fuels). Distribution is highly variable, leading to concentrated deposits in specific areas. This uneven distribution can cause conflict and has implications for national security and international relations.

  • Ore: Rock containing a high concentration of a particular mineral. Can be high-grade (high concentration) or low-grade (low concentration).

    High-grade ore has a higher concentration of the desired mineral, making extraction more profitable. Low-grade ore has a lower concentration, requiring more processing and potentially resulting in more environmental impact.

  • Reserves: Identified resources that can be profitably extracted at current prices.

  • Mineral extraction: Methods include surface mining (open-pit, strip, contour strip, mountaintop removal) and subsurface mining. All methods create some environmental disturbance; some have severe impacts.

  The General Mining Law of 1872 in the US, designed to encourage hard rock mining on public lands, has led to significant environmental degradation and cleanup costs.

  ⏳ Depletion Time and Sustainability ♻

  • Depletion time: The time it takes to exhaust a nonrenewable mineral resource. Recycling extends depletion time.

  • Mineral conservation: Reducing use and waste of mineral resources.

  • Materials revolution: Development of new materials as substitutes for metals (e.g., silicon, ceramics).

  • Recycling: Significantly reduces environmental impact and saves money. Higher prices for scarce minerals can increase supplies and encourage more efficient use. However, economics plays a large role in determining what proportion of a known supply is actually extracted and utilized. National policies can significantly influence this.

  🌊 Ocean Mineral Resources 🌊

  • Many minerals exist in seawater and on the deep ocean floor, but extraction costs are currently high.

  • Hydrothermal vents contain rich deposits of valuable metals.

  • Manganese nodules on the ocean floor represent another potential resource. However, ownership and extraction rights are subject to international disputes.

  In 1900, the average copper ore mined in the US contained 5% copper by weight; today it's only 0.5%. This illustrates the increasing challenge of extracting minerals from lower-grade ores.

  🔬 Nanotechnology and Sustainable Practices 🔬

  • Nanotechnology: Manipulation of atoms and molecules to create new materials. Offers promise but requires careful investigation of potential risks.

  • Waste prevention: A key aspect of cleaner production; exemplified by companies like 3M.

  Key Terms

  Term	Definition
  Area strip mining	A type of surface mining where a strip of land is mined and then restored, creating a series of parallel trenches.
  Asthenosphere	The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
  Contour strip mining	Surface mining method following the contours of the land, creating a series of terraces along hillsides.
  Core	The central part of the Earth, consisting mainly of iron and nickel.
  Crust	The outermost solid shell of the Earth.
  Depletion time	The time it takes to use up a certain proportion (often 80%) of a mineral resource at a given rate of use.
  Earthquake	A sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.
  Geology	The science that deals with the earth's physical structure and substance, its history, and the processes that act on it.
  High-grade ore	Ore with a high concentration of the desired mineral, making extraction more profitable.
  Igneous rock	Rock formed from the cooling and solidification of magma or lava.
  Lithosphere	The rigid outer part of the earth, consisting of the crust and upper mantle.
  Low-grade ore	Ore with a low concentration of the desired mineral, requiring more processing and potentially resulting in more environmental impact.
  Mantle	The region of the earth's interior between the crust and the core.
  Metamorphic rock	Rock that has undergone transformation by heat, pressure, or chemical reactions.
  Mineral resource	A naturally occurring material that can be extracted and processed to obtain useful substances.
  Mountaintop removal	A surface mining technique that removes the tops of mountains to access coal seams.
  Open-pit mining	A surface mining method involving excavating a large, open pit to extract minerals.
  Ore	A naturally occurring solid material from which a metal or valuable mineral can be profitably extracted.
  Rock cycle	The series of processes that create and change rocks on Earth.
  Sedimentary rock	Rock formed from the accumulation and cementation of sediments.
  Smelting	A process used to extract metals from their ores by heating them to a high temperature.
  Spoils	Waste material removed during mining operations.
  Strip mining	A surface mining technique where the overburden is removed to expose mineral deposits.
  Subsurface mining	Mining that takes place underground.
  Surface mining	Mining that takes place on the surface of the earth.
  Tectonic plates	Large, moving pieces of the Earth's lithosphere.
  Tsunami	A series of waves caused by underwater earthquakes or volcanic eruptions.
  Volcano	A rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
  Weathering	The breaking down of rocks, soil, and minerals as well as wood and artificial materials through contact with the Earth's atmosphere, water, and biological organisms.

AI make like a hundred flashcards and include stuff that’d be on a test. also i give you more materials if theres any overlap do one

Unit 4: Earth Systems 🌎

14.1 Plate Tectonics tectonic plates

Objectives, Essential Knowledge, & Skills

This section outlines the core concepts and skills related to plate tectonics.

Earth's Structure

• Core: A dense mass of solid nickel, iron, and radioactive elements that release massive amounts of heat.

• Mantle: A liquid layer of magma surrounding the core, kept liquid by intense heat from the core.

• Asthenosphere: A solid, flexible outer layer of the mantle, beneath the lithosphere.

• Lithosphere: A thin, brittle layer of rock floating on top of the mantle (broken up into tectonic plates).

• Crust: The very outer layer of the lithosphere; Earth's surface.

Plate Boundaries

Convection Cycles 🔄

Tectonic Map Predictions 🗺

• Ring of Fire: A pattern of volcanoes all around the Pacific plate. Predicts locations of volcanoes and earthquakes.

• Offshore island arcs: (e.g., Japan) Indicate convergent plate boundaries.

• Transform faults: Likely locations of earthquakes.

• Hotspots: Areas of especially hot magma rising up to the lithosphere. (e.g., Iceland, Hawaii)

4.1 Practice FRQ

Explain how subduction leads to volcanic activity.

14.2 Soil Formation & Erosion 🌱

Objectives, Essential Knowledge, and Skills

This section will cover the processes of soil formation and erosion, along with their impacts.

What is Soil?

Soil Formation Factors

• Parent material: Influences soil pH and nutrient content.

• Topography: Steep slopes lead to erosion; level ground promotes deposition.

• Climate: Warmer temperatures and more precipitation accelerate weathering and soil formation.

• Organisms: Soil organisms like bacteria, fungi, and worms break down organic matter and recycle nutrients.

Soil Horizons

Soil Loss and Degradation

• Loss of topsoil: Tilling and loss of vegetation disturb soil and make it more easily eroded.

• Nutrient depletion: Repeatedly growing crops on the same soil removes key nutrients.

• Compaction: Compression of soil by machines reduces its ability to hold moisture and support plant growth.

4.2 Practice FRQ

Design an investigation to measure the effect that climate has on soil formation. Identify the independent and dependent variables in your experiment.

14.3 Soil Composition & Properties 🧪

Objectives, Essential Knowledge, and Skills

This section will cover soil particle size, texture, and porosity, along with their effects on soil fertility.

Soil Particle Size, Texture, and Porosity

• Soil particles (largest to smallest): Sand > silt > clay.

• Soil texture: The percentage of sand, silt, and clay in a soil sample. Always adds up to 100%.

• Porosity: The amount of pore space in a soil. More sand = more porous; more clay = less porous.

Soil Texture Chart

(A soil texture chart would be included here if space and format allowed)

Soil Fertility

Factors Affecting Soil Fertility and Water Holding Capacity

4.3 Practice FRQ

Identify and describe one test that can be conducted on a soil sample. Explain how the results of the test could allow you to give advice to a farmer trying to grow crops in the soil.

14.4 Atmosphere ☁

Objectives, Essential Knowledge, and Skills

This section covers the composition and characteristics of Earth's atmosphere.

Gases of Earth's Atmosphere

Characteristics of Atmospheric Layers

Temperature Gradient

Atmospheric Science Lecture Notes

🌎 Troposphere Temperature Profile

The troposphere exhibits an inverse relationship between temperature and altitude. This is because the troposphere is warmed by UV rays from the sun, primarily at the Earth's surface (like a pool surface warming up). As you move higher in altitude, you get further from this heat source, resulting in a temperature decrease.

💨 Global Wind Patterns 🌬

Global wind patterns are driven by three main factors:

1. Energy from sunlight: More intense sunlight at the equator heats the air, making it less dense and causing it to rise.

2. Density properties of air: Warm air is less dense than cold air and rises, while cool air sinks.

3. Rotation of Earth (Coriolis effect): The Earth's rotation deflects moving air, influencing wind direction.

Here's a breakdown of the air circulation:

1. At the equator, warm air rises, creating a zone of low pressure.

2. As the air rises, it cools and expands, eventually sinking down around 30° N and S latitude, creating zones of high pressure.

3. This sinking air then flows back toward the equator (0-30° latitude winds blow from East to West) and towards 60° latitude (30-60° winds blow from West to East), completing the cycle.

Wind Patterns Summary:

💦 Watersheds & The Chesapeake Bay 🏞

A watershed is all the land that drains into a specific body of water (river, lake, bay, etc.). The boundaries of a watershed are determined by the slope of the land; ridges divide watersheds, directing runoff in different directions. Factors influencing drainage include:

• Vegetation

• Soil composition

• Slope

The Chesapeake Bay watershed is a large region encompassing six states, draining into the Chesapeake Bay. It's an estuary, a mix of fresh and saltwater. The bay's salt marshes are highly productive ecosystems, providing several ecosystem services:

• Tourism revenue

• Water filtration

• Habitats for food sources (fish & crabs)

• Storm protection

Human Impacts on the Chesapeake Bay:

Major pollutants include:

• Nutrient pollution (N & P) leading to eutrophication (algae blooms, oxygen depletion) from sources such as:

  • Sewage treatment plants

  • Animal waste from CAFOs

  • Synthetic fertilizers

• Endocrine disruptors from sewage

• Sediment pollution from deforestation, urbanization, and agriculture, increasing turbidity and harming habitats.

☀ Solar Radiation & Earth's Seasons 🌍

Insolation is the amount of solar radiation reaching an area, measured in Watts/m²/s. Solar intensity depends on:

• Angle: How directly the sun's rays strike the Earth's surface. The equator receives the most direct rays.

• Amount of atmosphere the rays pass through: Rays passing through less atmosphere deliver more energy.

Albedo is the proportion of light reflected by a surface. Higher albedo surfaces (like ice and snow) reflect more light and absorb less heat, while lower albedo surfaces (like water) absorb more heat.

🗺 Earth's Geography & Climate 🏔

Climate is largely determined by insolation (latitude and angle of solar radiation). Higher latitudes receive less insolation, resulting in cooler temperatures and less precipitation. The equator receives the most intense insolation, leading to higher temperatures and abundant rainfall.

Geography also plays a significant role:

• Mountains: Disrupt wind patterns and produce a rain shadow effect.

• Oceans: Moderate temperatures and add moisture to the air.

🌊 El Niño & La Niña 🌧

El Niño-Southern Oscillation (ENSO) is a pattern of shifting atmospheric pressure and ocean currents in the Pacific Ocean. It oscillates between El Niño (warmer, rainier conditions) and La Niña (cooler, drier conditions) phases.

Normal Year:

• Trade winds blow from east to west, pushing warm water toward the western Pacific.

• Upwelling occurs off the coast of South America, bringing nutrient-rich cold water to the surface.

El Niño:

• Trade winds weaken or reverse.

• Warm water moves eastward, suppressing upwelling off the coast of South America.

• Results in warmer temperatures and increased rainfall along the South American coast, while causing droughts in Australia and Southeast Asia.

La Niña:

• Trade winds strengthen.

• Increased upwelling off the coast of South America.

• Results in cooler temperatures and decreased rainfall along the South American coast, while producing more rain in Australia and Southeast Asia.