Detailed Course Information – Geography 120

Geography 120: Earth Systems II: Atmospheric Environment

Instructor: John Arnfield

Course Description

This course is the second of a two-course sequence in Earth Systems offered cooperatively by the Departments of Geological Sciences and Geography. In Earth Systems I, students are introduced to various aspects of the geological environment of the Earth. In this course, understanding of our planet’s systems will be extended to encompass the atmospheric environment. These two courses cannot be viewed in isolation from one another. The physical systems of the natural environment are characterized by an extraordinary richness and complexity involving exchanges of energy and matter among its components (the solid earth, the atmosphere, the oceans and living things, including humans). As a result, the processes of the global environment and the global distributions of phenomena which result from the operation of these processes, are linked in ways which transcend traditional disciplinary boundaries and the course offerings of individual departments. Students are expected to make use of concepts taught in Geological Sciences 100 and will deal with systems in this course which interact significantly with those treated with in the preceding one.

Course Objectives

The objectives of this course are as follows.

  • To introduce students to the nature of the atmosphere and to the processes by which it operates to produce the phenomena of weather and the global distributions of climatic elements and types.
  • To investigate the ways in which the systems of the atmosphere interact with those of the lithosphere and hydrosphere (covered in Geological Sciences 100), how materials and energy are cycled in ways which involve the total planetary system and how the methods and findings discussed in Earth Systems I can be used in the study of atmospheric history.
  • To discuss ways in which atmospheric systems interact with human systems. This includes both ways in which the atmosphere directly and indirectly influences human beings and ways in which human technology is playing a role in the functioning of the weather and climate system.
  • To provide students with a sense of the ways in which scientists studying the atmosphere go about their work, how they integrate different methodologies, and what tools and techniques they employ.
  • To emphasize that, because of the richness and complexity of the systems of the lithosphere, hydrosphere, atmosphere and biosphere, modern studies of global environment require the involvement of scientists trained in different disciplines.


Classes in Earth Systems II are of two types, lectures and recitations.

Lectures (two 80-minute lectures per week) are of two types. “Fundamentals” (see Course Outline below) cover the basics of the functioning of the atmospheric system and their manifestation in the phenomena of “weather” and “climate”. “Applications” treat some of the ways in which these phenomena interact with human systems. The specific topics included within each category are identified under Course Outline below.

In addition, a recitation class (one 80 minute meeting per week) will provide opportunities to perform practical exercises (calculations, work with maps, charts etc) involving material covered in lectures and in the text. Exercises will be discussed in the recitation classes and will contribute to your overall performance in the course (see Assessment, below).


Geological Sciences 100 (Earth Systems I: Geological Environment). There are no formal mathematics prerequisites for this course. However, in order to complete practical work, you will be expected to have a facility with mathematical techniques to the college entrance level.

Required Reading

The textbook for the course is: Ahrens, C. Donald, 1993, Essentials of Meteorology: An Invitation to the Atmosphere, West Publishing Co. The text is supplemented by a number of additional readings.


The course grade depends on the student’s performance in two term examinations (each worth 20%), a final examination (worth 40%), and exercise work (worth 20%).

Course Outline

  • Fundamentals 1: Earth Systems – the example of the global carbon cycle.
  • Fundamentals 2: Introduction to the atmosphere (composition, origins, vertical structure).
  • Fundamentals 3: Global energy budget (earth-sun relationships, solar radiation, terrestrial radiation, the heat budget for the globe and by latitude).
  • Applications 3a: Ozone depletion in the stratosphere (human activities, the “ozone hole” and international cooperation)
  • Applications 3b: Global warming and the enhanced greenhouse effect.
  • Fundamentals 4: Air temperature (heat and temperature, scales and measurement, controls on temperature).
  • Fundamentals 5: Atmospheric humidity, and the phenomena of condensation (the hydrologic cycle, change of state, humidity variables and saturation, dew, frost, fog, adiabatic temperature changes, atmospheric stability classes).
  • Applications 5a: The human energy budget: weather and human comfort.
  • Fundamentals 6: Cloud development and precipitation (clouds, precipitation processes, types of precipitation).
  • Fundamentals 7: Air pressure and winds (gas laws, the forces leading to atmospheric acceleration, relationship of horizontal and vertical winds).
  • Fundamentals 8: Global circulation (idealized and observed circulations, the tropics, the extratropics, local winds, global precipitation patterns).
  • Applications 8a: Times of feast, times of famine: atmospheric circulation and drought.
  • Fundamentals 9: Air masses, fronts and mid-latitude storms (air masses, air mass modification, properties of North American air masses, fronts, wave cyclones).
  • Fundamentals 10: Weather forecasting.
  • Fundamentals 11: Severe weather (thunderstorms, tornadoes, hurricanes).
  • Applications 11a: Extreme weather events and risk.
  • Fundamentals 12: Air pollution.
  • Fundamentals 13: Climate change (small scale changes, global scale changes, evidence and hypotheses).
  • Applications 13a: The climates of cities.
  • Fundamentals 14: Global climate distribution (controls, climatic regions).

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Updated: 16/09/2018