Physical Geography Lecture Notes

Exam Coverage

• Test One:
  • Chapter 1: Introduction to Geography and Earth Systems Science
  • Chapter 2: Portraying Earth
  • Chapter 3: Earth Sun Relations

Fundamental Concepts in Geography

• Geography: Study of spatial patterns of "Things"; involves holistic thinking.

  • Overlaps with various sciences.

• Cartography: Art and science of making maps.

Five Themes of Geography

1. Location:
   • Absolute (e.g., coordinates, addresses)
   • Relative (in relation to other locations)
2. Place: What occurs at a location.
3. Human Environment Interaction: Example: LA Basin and smog.
4. Movement: Like migration, relocation, and changes due to movement.
5. Region: Unique spatial patterns and scientific inquiries.

Physical Geography

• Branch dealing with Earth's natural features and processes.
• Referred to as Earth Science; encompasses:
  • Biosphere
  • Hydrosphere
  • Lithosphere
  • Atmosphere

Measuring the Earth

• Latitude and Longitude: Used for absolute location.
  • Equator, prime meridian, hemispheres.
• Earth's Shape: Oblate spheroid—equatorial diameter slightly larger.

Geographic Grid

• Latitude (Y-axis):
  • Divides Earth into Northern and Southern Hemispheres.
  • Key lines include North Pole, Arctic Circle, Equator, Tropics, and Antarctic Circle.
• Longitude (X-axis): Divides Earth into Eastern and Western Hemispheres.
  • Uses degrees, minutes, and seconds for precision.

Maps and Cartography

• Maps convey specific information.
• Types of Maps:
  • Topographic
  • Thematic
• Projection Issues: Distortion in size, shape, area, distance, and direction (SSADD).
• Map Scales: Ratio/fraction, graphical, and verbal scales.

Geographic Information Systems (GIS)

• Integration of geography with computer science and remote sensing.

Earth and Sun Relationships

• Sun: Center of the solar system; energy source for Earth.
  • Shortwave energy; distance to Earth ~93 million miles.
• Earth's Orbit: Elliptical; concepts of perihelion and aphelion.
• Seasons: Caused by Earth's axial tilt.
  • Key concept: Insolation and its distribution.
• Factors Influencing Insolation:
  1. Sun's temperature
  2. Earth's distance from the sun
  3. Absorption and scattering
  4. Latitude

Earth's Rotation

• West to East; 24-hour rotation, affecting day length and climate.
• Coriolis Effect: Influences movement of winds and ocean currents.

Atmosphere

• Essential for life, composed mainly of nitrogen and oxygen.
• Chemical Layers:
  • Heterosphere: Above 80-85 km
  • Homosphere: Below 80 km
• Temperature Layers:
  • Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere
• Air Pressure: Decreases with altitude; measured by barometer.

Weather and Climate

• Weather: Short-term atmospheric conditions.
• Climate: Long-term averages of weather over time and space.
• Climate Controls:
  1. Latitude
  2. Land and water distribution
  3. Atmospheric and oceanic circulation
  4. Topography
  5. Altitude
  6. Earth's rotation
  7. Storms
• Energy and Heat: Concepts of insulation, conduction, convection, radiation.

Greenhouse Effect

• Vital for life; enhances by human activity.
• Greenhouse Gases: CO2, water vapor, methane.
• Heat Transfer Laws:
  • Conservation of energy; transfer from high to low concentrations.

Atmospheric Dynamics

• Cyclones (Low Pressure) and Anticyclones (High Pressure): Influence weather patterns.
• Wind Patterns: Affected by pressure gradients, Coriolis effect, and friction.

Atmospheric Moisture

• Humidity: Energy from condensation; states of water transformation.
• Cloud Formation: Saturation, dew point, and relative humidity.

Precipitation

• 5 C's of Rain:
  1. Evaporation
  2. Cooling
  3. Condensation
  4. Coalescence
  5. Falling

Storms and Weather Systems

• Air Masses: Large volumes of air with uniform temperature and moisture.
• Fronts: Zones of transition between air masses.
• Tropical Cyclones: Develop in homogenous air masses, driven by water vapor and heat.

Climate Zones and Types

• Koppen Classification: Widely used system based on temperature and precipitation averages.
• Main Climate Types:
  1. Tropical Humid
  2. Dry
  3. Mid-Latitude
  4. Severe Mid-Latitudes
  5. Polar
  6. Highland

Climate Change

• Long-term changes influenced by natural cycles and human activity.
• Reconstruction Techniques: Historical records, dendrochronology, ice cores, etc.
• Milankovitch Cycles: Affect Earth's insolation and climate patterns.

Soils and Agriculture

• Arable Land: Decreasing; concerns for agriculture sustainability.
• Soil Composition: Minerals, air, water, organic materials.
• Soil Layers (Horizons): Different layers provide specific functions.

Biosphere and Biogeography

• Biogeography: Distribution of life on Earth.
• Nutrient Cycles: Carbon, nitrogen, oxygen, and water cycles essential for life.