ENB 150 Chapters 8, 11, and 9

Atmosphere

A dynamic envelope of gases extending up from Earth’s surface that clings to our planet because of gravitational pull

Composition of the Atmosphere

Nitrogen - 78%

Oxygen - 20%

Inert and other gases (mainly argon) - 0.96%

Water vapor - 1%

Different layers of the atmosphere have different pressures, temperatures, and compositions

Pressure

The force exerted on or acting against something

Troposphere

The lowest area of the atmosphere from 5 to 10 miles above the surface where Earth’s weather occurs

Dynamic - change is happening, weather is happening

Warm at the surface and decreases when you go up

This is where you are when you are flying in a plane

Tropopause

This is between the troposphere and stratosphere

Water does not go past the troposphere so we keep water (good)

Stratosphere

The layer of the atmosphere above the troposphere. It holds a layer of ozone that protects and warms Earth.

Calm, not a lot of dynamic changes, where the ozone layer is

Ozone is a gas that absorbs ultraviolet solar radiation (prevents skin cancer)

Temperature is warming up because the ozone gases are holding in the heat

Mesosphere

The layer of atmosphere above the stratosphere. It has Earth’s coldest temperatures and is where most meteors burn up

It is getting colder (coldest part of the atmosphere)

Where meteors burn up from the friction of hitting the gas particles in the atmosphere

Thermosphere

The top layer of the atmosphere. It is very thin and where most man-made satellites orbit because of the gravitational pull

Where temperatures stabilize

For objects to be able to leave the pull of the atmosphere, they would need to leave this layer

Weather

Short-term variations in conditions such as temperature, moisture, and wind in a specific place

Climate

The long-term average of weather conditions for a given region

Temperature

In common terms, a measure of the hotness or coldness of something; formally, a measure of how vigorously the atoms in a material are moving and colliding with each other

Causes weather

• Earth is warmed by the sun due to solar radiation reaching Earth’s surface

• Earth rotates - sun is not equally on every surface

• Uneven exposure - equator bulges out so it is constantly exposed to direct sunlight compared to other parts

• Land vs. Water - Land heats up (and therefore changes) faster than water because water takes more energy to heat up (water does hold the heat for longer)

Water Vapor

Causes weather

Humidity and Relative Humidity

Humidity

The amount of water in a given volume of air

How much water is in the air

Causes Weather

Relative humidity

The amount of water in the air as a percentage of the maximum amount of water that the air can hold at a given temperature

How much water in the air has to do with temperature

Causes weather

Barometric Pressure

A measure of the pressure exerted by Earth’s atmosphere at any given point

We have pressure because there is air above us (has mass), pressure decreases because there is less air pressure the higher you go up (harder to breathe)

Air Mass

A large volume of air typically several kilometers thick and a thousand or more kilometers wide that has relatively uniform temperature and humidity

High-Pressure System

A system of air formed by cooling air that becomes denser and heavier and then sinks to form an area of high pressure. It is usually associated with clear, dry conditions.

Cold air sinks, air spirals out clockwise

Usually associated with good weather

Usually depicted in blue (think blue sky = nice weather)

Low-Pressure System

A system of air in which warm, rising air cools as it expands into higher and colder altitudes. The cooling can cause the water vapor in the air mass to condense into clouds that may eventually produce precipitation

Warm air rises and other air rushes in and that movement causes a counterclockwise movement of air

Usually associated with bad weather

It is usually depicted in red (bad weather)

Wind

Air in motion as it flows from high-pressure to low-pressure areas

Prevailing winds from cells do not move in a straight line but are bent by Earth’s rotation

Fronts

Usually form at the boundaries between high- and low- pressure areas

Cold Front

A cold air mass replacing a warm air mass

Warm Front

A warm air mass replacing a cold air mass

Hadley Cell

A looping weather pattern forming circulation systems between the equator and latitude 30° S.

Ferrel Cell

An air circulation pattern between latitudes of 30°N and 60°N and between latitudes 30°S and 60°S

Jet Stream

A prevailing wind pattern near the top of the troposphere

Air pollution

What occurs when the addition of materials into the atmosphere adversely affects the health of humans and/or other organisms.

Primary Pollutant

A substance that is harmful in its directly emitted form

The thing that is released is the pollutant

Harmful in its directly emitted form

E.g., Particulate Matter (PM), toxic metals (e.g., mercury & lead), and Volatile Organic Compounds (VOCs)

Particulate Matter (PM)

Tiny particles and droplets less than 10 micrometers in size - about one-seventh the diameter of a strand of human hair - that are suspended in the air we breathe

Small matter that you inhale that causes a lot of harm because of its size (you can inhale it really deep because it is so small).

It is not what it is made of that is the main problem (it can be), but it is the size.

Toxic Metals

• Mercury

  • Starts out as an air pollutant and organisms collect it as Mercury falls (dangerous when a lot is collected)

  • Plant Scherer → coal (mercury is a part of coal)

    • 2008-2009 became stricter

• Lead

  • pipes, gasoline

• *Both have an impact on children with developing brains

Volatile Organic Compound (VOC)

A gas released through the evaporation or incomplete combustion of fossil fuels and other organic chemicals

Organic means that this came from fossil fuels

E.g., formaldehyde, toluene, & acetone

Really strong smells → have chemicals that can be released as smells really easy

Starts as an oil (suite of chemicals) that can become gaseous once released (smell)

Secondary Pollutant

A pollutant that is the product of reactions occurring in the atmosphere

Pollutant mixes with something in the air and that mixture becomes the thing that we are concerned about

E.g., Smog, Chlorofluorocarbons (CFCs), and Acid Rain

Smog

A secondary pollutant that forms when chemicals from the combustion of fossil fuels interact in the presence of sunlight at warm temperatures

Forms when VOCs and Nitrogen Oxides (NO_x) from fossil fuel combustion interact with sunlight at warm temperatures

Forms ground-level ozone (also secondary) → breathing it is bad for our lungs, in the atmosphere it is fine because we are not breathing it

Chloroflurocarbons (CFCs)

• Ozone layer decline

• Stratospheric ozone absorbs 99% of ultraviolet (UV) radiation

• CFCs destroys stratospheric ozone

  • Increases cancer rates

  • Montreal Protocol (1987) phased out CFCs

    • Ozone recovery expected in 2066

Acid Deposition

• A phenomenon where air pollutants react with water making an acid that precipitates from the sky, also known as “acid rain”

• Rainwater is slightly acidic (pH of 5.6)

• Sulfur Dioxide (SO₂) and Nitrogen Oxide (NO_x) react with water vapor, form sulfuric acid and nitric acid

  • Makes rain more acidic

• Burning fossil fuels → mix with water vapor → acid rain → damage to vegetation → acid leaching in runoff/groundwater → acidification of water and damage to aquatic ecosystems

Clean Air Act of 1970

A law that established two important policy strategies: air quality standards and regulations on the source of pollutants

Established air quality standards and regulations on source of pollutants

Energy Policy and Conservation Act

A 1975 act that set minimum miles per gallon (mpg) fuel-economy standards for cars and light trucks

Set minimum miles per gallo (mpg)

Tradable Emission Allowance

A strategy where the EPA sets the total level of allowable emissions for a pollutants from utilities, then divides the this total into tradable units called allowances that are bought and sold

Global Climate

the average weather conditions over a significant period of time for the planet as a whole.

Instrumental Period

the current era in which we have access to temperature readings taken directly with instruments such as thermometers.

Ability to put a clear distinct number on temperature instead of being like, “it feels warmer.”

Looks at how temperature deviates from the average

Weather Satellites (1979) - Comprehensive data worldwide that is not just about weather, but about the movement of clouds

Geothermal Gradient

how temperature increases with depth in Earth's crust due to decaying radioactive elements.

Proxy

an observable and measurable phenomenon that serves as an indirect indicator of changes in climate.

Way to measure temperature without a thermometer, understanding how something works that can give us a measure of temperature

indirect indicator of climate change

E.g., tree rings, coral skeletons, ice cores (go way back)

Paleoclimate

ancient climate conditions understood through use of proxies.

Greenhouse Effect

any system where a barrier causes the inflow of energy to outpace the outflow in a way that warms the interior. Specifically, the warming effect on Earth due to atmospheric greenhouse gases that prevent radiant heat emitted from the surface from escaping into space.

Albedo

a measure of the reflectivity of a surface.

Natural Factors in Climate Change

• Greenhouse Gases (GHGs)

• Carbon Dioxide (CO₂)

• Methane (CH₄)

• Nitrous Oxide (N₂O)

  • These are naturally occurring

• Halocarbons (CFCs, HFCs) - manmade

• Water vapor - Presence of clouds

• Temperature corresponds to the amount of carbon dioxide

Greenhouse Gas

a gas in the atmosphere that redirects heat rising from Earth's surface back toward the surface, causing a warming effect.

think about a car in the summer

Milankovitch Cycles

regular patterns of variation in the shape of Earth's orbit and the tilt and direction of Earth's rotational axis. These alter the amount of the Sun's radiation and energy that reach Earth and its atmosphere.

Patterns of warming and cooling due to shifts in the Earth’s orbit → Change over long periods

• Orbit: 100,000

• Tilt: 40,000

• Axis Wobble: 26,000

Each impact how much sun the Earth gets

Continental Drift

Important for climate because depending on location, land can be closer to the equator (getting warmer), or the poles (getting cooler) which impact the overall climate

Uplift and Erosion

Formation of mountains (continents smush together while moving), changes how land interacts with the sun

Erosion → carbon that erodes into water impacts organisms

Volcanic Eruptions

Cools climate because the ash/sulfuric acid blocks the sunlight (large volcanoes)

Asteroid Strikes

Impacts how organisms survive and introduces/shoots new things into the atmosphere and Earth

Indicators of a Warming World

• Glacier Mass, Snow Cover, Arctic Sea Ice

• Air Temperature and Humidity

• Sea Level and Sea Surface Temp

• GHG

Glacier Mass, Snow Cover, Arctic Sea Ice

• All decreasing

• Most mountain glaciers are retreating

• Area covered by snow in the Northern Hemisphere is starting to shrink

• Area covered by sea ice in the Arctic each Summer is decreasing

  • Younger and Thinner

Air Temperature and Humidity

• Air temperature is rising

• Increased evaporation of warming waters leads to more water vapor in the air

• Air temperature in lower atmosphere is getting warmer

Sea Level and Surface Temperature

• Sea level is rising

• The air just above the ocean surface is warming, allowing more water to evaporate

• Heat content and surface water temperature are increasing/warming

• E.g., Isle de Jean Charles, Lousiana & Miami, Florida

GHG

• They are increasing climate because the amount of GHG are increasing

• Seasons cause variability because trees change in the Summer → trees take in carbon dioxide to photosynthesize and in the winter (no leaves) → the carbon dioxide is not taken out of the atmosphere

GHGs are Increasing

• Carbon Dioxide → sources: coal, oil, gas, cement production

• Methane → coal mining, landfills, manure, enteric fermentation (cows), natural gas and petroleum systems

  • Methane venting: Pipes sticking out of hills (area used to be a landfill) allows methane to go into the atmosphere

  • burning

• Nitrous Oxide → agricultural soil movement (fertilizer)

• Halocarbons → no natural sources (substitution of ozone depleting substances), high warming effect

Effects of Climate Change

• Increase in the global average temperatures

• Precipitation and the water cycle

• Hurricanes and severe weather

• Sea level rise

Increase in the global average temperature

• Surface temperatures continue to rise

• More frequent and intense heatwaves

Precipitation and the Water Cycle

• More frequent and intense rainfall

• More frequent and intense droughts

Hurricanes and Severe Weather

• Warm oceans and evaporating water feed tropical storms

Sea Level Rise

• melting ice

• thermal expansion: when water warms, it takes up more space

Surface Current

an ocean current affecting the top 400 meters of water that starts because of air blowing across the water surface.

Gyre

a large circular ocean current.

Coriolis Effect

a force driven by Earth's rotation that deflects objects, winds, and currents on the surface of Earth and in the ocean or the atmosphere.

Deep Current

the flow of ocean water below the surface caused by variations in density, temperature, and salinity.

Salinity

the concentration of salt in water, generally measured in parts per thousand.

Thermohaline Conveyor

a large-scale ocean circulation driven by surface and deepwater ocean currents and changes in water temperature and salinity (density).

El Niño - Southern Oscillation (ENSO)

a change from normal ocean currents that significantly weakens or even shifts the direction of trade winds and ocean currents in the southern Pacific.

Upwelling

a place where ocean currents draw up colder water from the deep.

Hindcasting

a scientific technique where simulations are run on a particular model to see how its predictions match up to actual or historical real-world observations.

Drought

a prolonged period of low precipitation and high evaporation rates that can lead to water shortages.

Thermal Expansion

the expansion of something as it warms, in particular, the water in the oceans, which increases sea level.

Ocean Acidification

the ongoing decrease in the pH of Earth's oceans caused by absorption of carbon dioxide (CO₂) from the atmosphere.

In the ocean CO₂ becomes carbonic acid and can cause the seashells and coral reefs to dissolve

Ecosystem effect of climate change

Phenology

the study of the seasonal timing of biological activities/natural events, such as the breeding, flowering, and migration of various species.

E.g., turtles and butterflies

Impacts of Climate Change on Humans

Deaths (heat), increase in allergies, wildfires, property damage, respiratory problems, electric bills, droughts, flooding, insurance, illness, food shortages, agriculture, loss of pollinators, and water shortages

Feedback

a loop in a system that responds to and produces changes in levels of stocks that either amplify or counter a change.

Can be positive or negative

a cyclical process where the output of a system circles back to influence its own input

Positive Feedback Loop

a mechanism that amplifies change and moves a system further away from its starting point or equilibrium

The loop causes the initial change to keep increasing

Negative Feedback Loop

a mechanism that resists change to maintain stability, balance, or homeostasis

The loop causes the increases to go back to normal

Embodied Energy

the energy used to make and transport goods.

Earth’s Internal Structure

• Earth is 4000 miles deep to the center

• Drilling to the other side from here → Indian Ocean

Core

the center of Earth, with a solid inner section and a liquid outer section both made primarily of iron and nickel.

most dense

Magnetosphere

an area of space around Earth that shields the planet from charged particles emitted from the Sun.

As Earth rotates, core generates a magnetic field

Lots of organisms use this (e.g., compasses, monarch butterflies for breeding/migration).

Mantle

the rock section of Earth above the core and below the crust.

denser

84% of Earth’s volume (we have never been here because it is too hot = death)

We can measure seismic waves to indicate the material/how much material to indicate each layer

We can also analyze volcanoes because they bring the materials in the layers to the surface

Crust

Earth's outermost layer

Least dense

Earth does not have a solid piece of crust

Lithosphere

the rigid outer portion of Earth, consisting of the crust and the very top of the mantle.

asthenosphere

an area of Earth's mantle that is relatively pliable and is situated below the more rigid lithosphere.

Tectonic Plate

a section of Earth's crust that rides on top of denser material below; interactions among these plates shape Earth's surface.

Pushing these plates together causes mountains

Tectonic Plate Movements/Boundaries

1. Divergent Plate Boundary: ← →, Plates move away from each other, East African Valley

2. Convergent Plate Boundary: → ←, Plates collide or push towards each other, Himalayas

3. Transform Plate Boundaries: ↑ ↓, Plates slide horizontally past each other, San Andreas Fault

Fault

a fracture in Earth's crust, along which one body of rock slides past another.

At one point in history, all the continents fit together…and have slowly drifted apart

The faults cause the plates/continents to drift apart

Rock Cycle

the geologic process by which Earth recycles and renews its surface.

1. Rocks deep beneath the surface are brought to the surface by tectonic processes and erosion of the overlying rocks

2. Rocks at the surface are weathered and break into smaller particles

3. Erosion transports weathered rock particles and deposits them in places where they accumulate as sediment (sedimentation)

4. Buried sediment subjected to high pressure and temperature are transformed into layers of sedimentary rock

5. Heat and pressure at even greater depths can transform one type of rock into another through metamorphism (metamorphic rock)

6. Magma from molten crust and mantle become magma chamber

7. Igneous rocks are formed from cooling molten rock either at depth or when erupted onto the surface

Igneous Rock

rock formed by the cooling of molten rock

Weathering

physical and chemical processes that reduce rocks to smaller particles (such as gravel, sand, or silt) and alter minerals.

Physical: Water in a rock freezes → water takes up more space when frozen → water slowly pushes the rock apart into multiple smaller rocks

Chemical: Water can wash away the material or interact with the material (cause it to dissolve or create a mineral by washing elements together to be combined) to make the rock more brittle over time

Erosion

a process where natural forces—such as wind, water, ice, and gravity—move weathered rock particles.

Movement of weathered rock

Metamorphism

Rock changes into another type due to high pressure and temperatures

Sediment

eroded material that is transported and accumulates in different places.

Sedimentary Rock

rock formed when sediment buried under many layers of material cements together due to high pressures and temperatures.

Metamorphic Rock

rock produced when one type of rock changes to another because of extreme heat and pressure.

Mineral

a natural solid from Earth's crust that forms rocks. Minerals also provide key materials for many practical human endeavors.

They have specific components → crystals that are specific whereas rocks can be a bunch of minerals smushed together

Humans need calcium, magnesium, phosphorous, potassium, and sodium as well as trace minerals

We can consume these minerals from animals/plants because they get minerals from the soil

Landform

a surface feature of the landscape.