Physical Geography

Course Overview

• Course Content: Physical Geography of the Front Range, Colorado

  • Focus on landscapes, weather, climate, biogeography, and general atmospheric principles.

Course Schedule

• Week 1 (Aug 25-29)

  • Topic: Introduction to Landscapes

  • Assignment: None specified

• Week 2 (Sep 3-5)

  • Topic: Weather & Climate

  • Reading: Meinig (1979) Chapters 2 and 3

• Week 3 (Sep 8-12)

  • Topic: Weather & Climate

  • Reading: Meinig (1979) Chapter 5

  • Assignment: Exercise 1 Assigned

• Week 4 (Sep 15-19)

  • Topic: Weather & Climate

  • No specific assignments or readings noted

• Week 5 (Sep 22-26)

  • Topic: Weather & Climate

  • Activity: Driving GeoGuess - round 1

  • Reading: Meinig (1979) Chapters 4, 6, & 7

• Week 6 (Sep 29 - Oct 3)

  • Topic: Weather & Climate

  • Assignment: Presentations of Exercise 1 on the final day (Friday)

• Week 7 (Oct 6-10)

  • Activity: Continued Exercise 1 Presentations

• Week 8 (Oct 13-17)

  • Topic: Biogeography

  • Assessment: Quiz 1 (Available all week)

  • Reading: Meinig (1979) Chapter 8

Climate Data Overview

• GFS 2m Temperature Anomaly (°C)

  • Contains a 1-day average from Monday, September 8, 2025

• Parameters Measured:

  • 2m Temperature: Average, Max, Min

  • Categorization of Anomalies:

  • Precipitation, Clouds, Mean Sea Level Pressure (MSLP),

  • Precipitable Water, Jetstreams, Snow Depth, etc.

Global Radiation Balance

• Shortwave (Incoming) Energy

  • Greatest in the tropics

• Net Short-Wave Radiation

  • Seasonal variations noted (Dec to NCERNCAR dataset, 1965-1997)

  • Diagram illustrating energy balance dynamics

General Atmospheric Circulation

• Key Wind Patterns:

  • Trade Winds:

  • Characterized by two primary trade wind systems: Northeast and Southeast

  • Westerlies:

  • Significant for mid-latitude weather patterns

  • Jet Streams:

  • Polar Jet Stream and Subtropical Jet Stream influencing climate zones

• Hadley Cells and their role in tropical climate dynamics

Controls on Temperature

• Key Factors Influencing Temperature:

  • Latitude

  • Elevation above sea level

  • Land-Water contrasts (Continentality)

  • Ocean Currents and Circulation

  • Monsoon and Tertiary Circulations

  • ENSO (El Niño Southern Oscillation)

  • Cloud Cover effects on temperature maximums and temperature ranges

  • Topographic Position and Slope Aspect

• Note: Each factor will be revisited throughout the course

Elevation

• Mountain Reference:

  • Mount Elbert, Colorado: Highest peak at 14,433 feet

Atmospheric Composition and Structure

• Atmospheric Layers:

  • Troposphere:

  • Weather occurs; temperature decreases with altitude core; Normal lapse rate: $(6.4C°/1000m)$ or $(3.5F°/1000ft)$

  • Stratosphere, Mesosphere, Thermosphere:

  • Ozone layer present; detailed temperature profile from Polar to Tropics

  • Heterosphere vs. Homosphere: Differences in gas composition and behavior

Trends with Elevation Increase

• General Trends Noted:

  1. Temperature Decreases: Particularly in the Troposphere

  2. Air Pressure Decreases with altitude

  3. Air Density Decreases: Example noted is that air density in Denver is typically 15% less than that at sea level

Land-Water Heating Differences

• Maritime vs. Continentality Considerations:

  • Continental Conditions:

  • More extreme temperatures; land warms/cools quickly

  • Lower evaporation rates

  • Higher insolation

  • Marine Conditions:

  • More moderate temperatures; water warms/cools slowly

  • Greater evaporation leading to moisture retention

• Specific Heat Comparison:

  • Land has lower specific heat, whereas water's high specific heat results in thermal moderation and mixing within ocean currents

Comparative Temperature Regimes

• Case Study: Tucson, AZ vs. San Diego, CA

  • Average Monthly Temperatures (in °F):

  • Tucson: 50 (Jan) to 90 (Jun)

  • San Diego: 50 (Jan) to 75 (Jun)

  • Latitude Effect on Temperature Range:

  • Tucson: Range ~35°F

  • San Diego: Range ~16°F