Geography- Exam 1

Two divisions of Geography

1. Physical

2. Human/cultural geography

Physical geography

• Scientific study of Earth and its environments by analyzing air, water, land and living systems

  • Climate change

• Uses spatial perspective to examine processes and events happening at specific locations and times

• Three divisions, which combine to create geomatics

  • Biogegraphy

  • Climatology

  • Geomorphology

Biogeography

Division of physical geograpy. Study of land forms- how they are shaped, how they change, etc.

Biogeography

the scientific study of how plants, animals, and other organisms are distributed across the Earth,

Human/cultural geography

Understanding Anthropology, demograpy, history, and philosophy

Scale

Microscale- regional- global

Grain

Resolution of observations

Extent

Size of study area

Scale-dependant processes

• Outcome is dependant on the scale

• e.g. slope winds vs synoptic circulation

Scientific Process

• Observing, questioning, testing, and understanding elements of the natural world

• Organized steps leading toward concrete objectives and conclusions

Scientific Theory

An explanation constructed on the basis of several extensively tested hypotheses and can be reevaluated or expanded according to new evidence

Perihelion

• When we are closest to the sun (Jan 3)

• 147,225,000 km

Aphelion

• When we are farthest from the sun (July 4)

• 152,083,000 km

Plane of the ecliptic

The plane of Earths orbit

Earth’s distance from the sun

• 8 minutes 20 seconds

• 150,000,000 km

Goldilocks Planet

• Further enough away from the sun to support life- “just right”

• Drake equation: states that in our galaxy there should be about 10 advanced civilizations

NASA’s Kepler Mission

• Looks for planets in the habitable zone- the area where liquid water could pool on the surface which is vital for life

• Estimated to be 40 billion- confirmed 2778

• James Webbs space telescope

Geographic Spheres

• Atmosphere (air and water)

• Cryosphere (frozen, ice)

• Hydrospher (water- fresh and salt)

• Lithosphere (rocks)

• Biosphere (life)

Human-Earth Interactions in the 21st Century

• Issues concering the growing influence of humans on Earth systems are central concerns

• 8.26 billion (growing due to agriculture, medicine)

• New population growth is in the less-developed countries, 81% of population

  • Birth control and access to education

Systems analysis origination

• Began with studies of energy and temperature (thermodynamics) in 19th century

System

• Any set of ordered, interrelated components and their attributes, linked by flows of energy and matter, as distinct from the surrounding environment outside the system

• Change when inputs dont equal outputs, or when storage changes

• Can have deterministic and stochasitc variables

  • e.g. sports, mix of luck and predictability

Matter

A mass that assumes a physical shape and occupies space

Energy

A capacity to change the mo-tion of, or to do work on, matter

Stock

Whats stored (mass or energy)

Flows/fluxes

what moves in/out per time

Residence Time

Stock divided by outflow (how long material or energy tends to stay)

Deterministic System

A system whose temporal or spatial evolution can be exactly predicted. The output is the result of known relations between dependant and independant variables (e.g. dominos)

Stochasic System

• A system where the output is governed by a probability distribution

• Used to cover the idea of random and chance- only two possible outcomes

• E.g. coin flip and radioactive decay

Chaotic System

• Associated with deterministic events that are not predictable

• Outcome events occur along a bounded attracter

• e.g. a pendulum or planetary orbits

• Weather systems: even very small changes can lead to very different outcomes

Open Systems

• A system which is not self contained

Earth Systems

• Dynamic: open and closed system

  • Physical matter and resources stay, energy leaves

• Solar energy enters, heat energy leaves

• Energy transformed into kinetic energy, potential, and chemical or mechanical energy

• Many are non-linear

Nonlinear systems

• Small changes can have big effects near thresholds (tipping points)

• Hystersis/path dependance

• Thresholds can create abrupt shifts to a new state

Hysteresis/path dependance

Recovery does not necessarily follow the same path as change (the “return trip” differs)

Closed system

A system that is shut off from the surrounding environment, self contained

Forests and humans

• Creates outputs of carbon storage, soil stabilization, and food and resources

• Forests absorb about 1/3 of the carbon dioxide released through the burning of fossil fuels, which is problematic due to the rate

• Logging, burning, clearing, climate change

Steady-state equilibrium

• An energy and material system that remains balanced over time, in which conditions are constant or recur (like a bank account)

• Rates of input/outputs are equal and the amoutns of energy and matter in storage are constant

Dynamic Equilibrium

• The system fluctuates around a stable averages, but exhibits a changing trend overall

• May reach a threshold/tipping point, when the system jumps to a new stable average condition

Bathtub Analogy

• Inputs: water, from tap

• Outputs: water, out the drain

• Water level: constant, fluctuates about an average level (steady-state equilibrium)

• Water level: slows increases or decreases (dynamic equilibrium)

• Too much water: one leg breaks, tub tips over (threshold)

External Forcing

Pushes a system from outside (e.g. volcanic aerosols, solar variability, GHG changes)

Feedback

A response that amplifies or dampens the change (positive/negative)

Internal variability

Natural “wiggles” generated within the system

Positive feedback

• Increases the response or stimulates the processes in the system

• Input/output drive the system further toward an extreme

• e.g. planet heats up, glaciers melt, snow reduces, planet heats up more

• Initial disturbance that amplifies changes

• Much faster than negative feedback

Negative feedback

• Slows down processes in the system

• Input and output neutralize each others effects, stabalizing the system

• e.g. planet heats up, trees grow further north, trees take up CO2, reduced greenhouse warning

Coupling and cascading effects across spheres

• Earth’s spheres are coupled: a change in one can propagate to others

• Cascades often involve feedbacks

• Systems thinking helps identify leverage points (where intervention matters most)

• e.g., drought - wildfire - lower albedo/vegetation- soil changes - runoff/erosion - water quality impacts

Model

A simplified, idealized representation of part of the real work expressed in conceptual, physical, or mathematical terms

Conceptual Model

The most generalized, focuses on how processes interact within a system (e.g. biosphere, hydrosphere, lithosphere)

Physical Model

Scale down/up of a physical system (e.g. globe, chem model building kits")

Numerical Model

More specific, usually based on data collected from field or laboratory work (numerical weather prediction). Mathematical formulas representing relations between components of a system

Atmosphere

A thin, gaseous veil surrounding Earth, held to the planet by the force of gravity. Combination of nitrogen, oxygen, argon, carbon dioxide, water vapour, and trace gasses

Hydrosphere

• Where Earth’s waters exist in the atmosphere, on the surface, andin the crust near the surface. The portion that is frozen is the cryosphere

• Abiotic Sphere

Lithosphere

• Earths crust and a portion of the upper mantle directly below the crust

• Abiotic sphere

Biosphere

The intricate, interconnected web that links all organisms with their physical enviornment

• Biotic sphere

Direct Relationship

• Positive

• Inherently Unstable

• As variable one increases, variable 2 increases

• e.g. Variable One: Spring stream runoff, variable two: winter snowfall

  • greater winter snowfall, greaater spring stream runoff

Inverse Relationship

• Negative

• Stabilizing impact

• As variable one increases, variable two decreases

• e.g. variable one: clouds, variable two: solar radiation

  • as clouds increase, solar radiation reaching surface decreases

Benefits of systems theory

• Understanding systems is important so we can model them

• Stresses relationships: how the system can be altered by small changes

• increases likelihood of all relevant variables being included

• encourages quantification: helps make decisions

• helps prediction

  • Overall goal of understanding systems

• More info= easier decision making

Climate Modelling advances

• Numerical weather projecting has changed since the 1950s

  • better resolution, satellites, computer systems, communication

Black Box Theory

Understanding input and output, but not what happens in between (too complex or hidden)

• e.g. rainfall to runoff

Grey Box Theory

Fully understanding what occurs in the inputs/outputs, but only some of the middle

• e.g. rivers- where the water comes from

White Box Theory

• Understanding all processes: input, output, and the middle

• e.g. agriculture is greener because there is more water

What is the most effective way to send a message to the future?

Carve it into a rock

Rapid Progress examples

• Competion- space race

• war

• Fear of consequences

  • Montreal protocol: use of aerosols due to refridgerators led to holes in atmosphere, the pressure was hot to stop the chemical production

Examples of Stalls in progress

• Things burning down/being destroyed

  • Library of Alexandria burning

  • ISIS attacks on art

Temperature

• Measure of average kinetic energy

• Warmer to colder

• No upper limit, goes down to absolute zero (0K)

• HIgh concentration to low concentration

Four States of matter

1. Solid

2. Liquid

3. Gas

4. Plasma (stars)

   1. Super heated gas with electrically charged particles in it

Importance of States of matter

• Water phase changes

• Latitude changes influence vegetation

  • e.g. Vancouver to Winnepeg, Vancouver has more water in the air from the sea, so it holds a steadier temperature

Exogenetic Energy

• Anything that comes from the sun.

• Hydrosphere ,biosphere, lithosphere

• >99%

Endogenetic Energy

• Volcanic energy

• Power comes from heat source

• Moves landforms

• Earth’s magnetic field: vital for life, keeps radiation away

Alford Wegener

• Father of continental drift

• Could not propose a mechanism

Law of Thermodynamics

1. Energy can be created but not destroyed

2. Heat can never pass spontaneously from a colder to a hotter body; a temperature change can never occur spontaneously in a body at uniform temperature

• When cold, you are losing heat, not gaining cold

• Touching metal takes heat away faster because it is a better conductor

Radiation

Energy transfer from the sun

Conduction

Heat transfer through solids

Convection

Heat transfer through fluids (liquids and gases)

Sensible Heat

the energy exchanged by a substance that causes a change in temperature without altering its phase. e.g. heating water up

Latent heat

the energy absorbed or released by a substance during a constant-temperature phase change. Heat transfer, not temperature

Electromagnetic Specturm

Wavelength of all possible wavelengths of electromagnetic energy

Wavelength

The distance between corresponding points on any 2 successive waves of energy

Suns energy emission

Primarily in wavelengths of visible light and shortwave infared wavelengths

Radiation

Emitted by everything, characteristic is dependant on temperature

Electromagnetic Spectrum (short to long)

1. Gamma Rays

2. X-rays

3. UV Rays

4. Visible light

5. Near infared

6. shortwave infared

7. middle infared

8. thermal infared

9. microwaves

10. Radiowaves

Stefan Boltzman Law

• E=ConstantT4

• E is the intensity of radiation emitted by a black body

• T is absolute temperature

Black Body

Idealized physical body that absorbs all electromagnetic radiation falling on it. Does not reflect any energy. e.g. sun and Earth

Sun vs Earth radiated energy

• Sun = short-wave radiation that peaks in short, visible wavelengths. higher radiation

• Earth = long wave radiation concentrated in infared wavelengths. lower radiation

Wien’s Displacement Law

• tells the type of radiation

• determined by temperature

Thermopause

• Outer boundary of the Earth’s energy system (480 km)

• Thermopause above the equatorial region recieves 2.5 times more insolation annually than above the poles

How much of the sun’s energy does the Earth intercept?

0.5 - 10^-9 (half of one billionth) due to distance from the sun

Insolation

Total solar radiation intercepted by the Earth (surface and atmosphere)

Solar Constant

Average insolation recieved at the thermopause when the Earth is at the average distance from the Sun (1372 watts/meter squared)

Sub-Solar Point

• The only points where insolation arrives perpendicular to the surface (where the suns light is shining most directly). only occurs in the lower latitudes, causes the energy recieved to be more concentrated

• moves between 23.5* N and 23.5* S during the year

• Move from shining directly on the tropic of capricorn → cancer

Net Radiation

Balance between incoming short-wave energy from the sun and all outgoing radiation from the Earth

Seasonal Variations

A response to changes in the sun’s altitude→ angle between the horizon and the Sun

Declination

• The latitude of the sub-solar point

• Anually moves through 47 degrees of latitude

Day length

• Duration of exposure to insolation, which varies during the year, depending on latitude (more latitude, more day lenght variable)

• Equator always recieves equal hours of day and night

Seasons

• Result from variations in the Sun’s altitude above the horizon, the sun’s declination, and daylength during the year

• Created by the Earth’s revolution, daily rotation, tilted axis, and sphericity

Revolution

• Earths travel aroundf the sun. Earth’s speed and distance determine the time required for one

• Completed in 365.2422 days- why we have a leap year

Rotation

• Time it takes earth to turn on an axis

• Determines daylength

• Creates the winds and ocean currents

• Pruduces the ocean tides (twice daily)

• Takes slightly less than 24 hours

• West to East

Circle of Illumination

Dividing line between day and night

Axial Tilt

• Tilt of the Earth

• Changes over a 41,000 year cycle

• ranges from 22-24.5 degrees

• Currently lessening

Tropics of Cancer

• 23.5 Degrees North

Winter Solstice

• 21st of December

• Shortest day in the Northern hemisphere

• Sub-solar point on tropic of Capricorn

Arctic Circle

• 66.3 Degrees