GEG1301 Final Review Fall 2024 PDF

GEG1301 THE PHYSICAL ENVIRONMENT Final review Fall 2024 Prof: Roxanne Frappier Final exam Wednesday, December 18th 7:00 PM to 10:00 PM Minto Sports Complex, room 3 2 sections: Part A: 47 multiple choices (1 mark each) (~1/2 about content seen b...

GEG1301 THE PHYSICAL ENVIRONMENT Final review Fall 2024 Prof: Roxanne Frappier Final exam Wednesday, December 18th 7:00 PM to 10:00 PM Minto Sports Complex, room 3 2 sections: Part A: 47 multiple choices (1 mark each) (~1/2 about content seen before/after mid-term 2) Part B: 4 short answers (10 marks each) – choose 4 out of 5 questions Covers the entire course  This form will be on the front page of the exam. Fill it out only if you want to exclude one of your assignments from the calculation of your final grade for the course. Leave it blank if you do not which do exclude any assignment. You need to figure which (if any) assignment you want to exclude before arriving at the final exam. Review Positive and negative feedbacks Water and surface water balance Latitudes and longitudes Earth’s structure Solar wind Rock cycle Electromagnetic energy Tectonic forces Earth energy balance Weathering and erosion Solstices and equinoxes Soil Atmospheric profile Sediment transport in streams Factors influencing air Coastal waves temperatures Coastal erosion Forces acting on air movement in the atmosphere Types of glaciers and glacier erosion Atmospheric circulation patterns Permafrost Koppen climate classification Wind erosion System Feedback (ability to change themselves) Positive feedback enhances (magnifies) the original change Result increasingly differs from the starting state Tends to lead to instability/disruption in the system Negative feedback damps down (diminishes) original change Tends to preserve/diminish the starting state. Helps to stabilize and maintain the system Dividing the Earth Since the simplification of the Earth’s shape corresponds to an ellipsoid, circles are used to divide the Earth. Parallels (east-west lines defined by latitudes; never intersect) Latitudes are measured in degrees north or south of the equator Meridians (north-south lines defined by longitudes; intersect only at the poles) Longitudes are measured in degrees east or west of the prime meridian  Solar Activity and Solar Wind Solar wind: clouds of electrically charged particles (gaseous flow of energy + free electrons) that is generated by the Sun. These charges particles first interact with Earth’s magnetosphere and are deflected towards Earth’s poles. Wavelength and Frequency Radiant energy from the Sun travels in the form of waves Two ways of describing electromagnetic radiation: Wavelength: distance between 2 crests Frequency: # of waves passing a fixed point in 1 second Copyright © 2013 Pearson Canada Inc.  max= 0.48 m max= 10.2 m (Sun) (Earth) Visible part Infrared portion Wavelength of radiated energy depends on the temperature of the radiating body. Sun is much hotter, so radiates shorter wave energy, mainly visible and near infrared. 8% ultraviolet, X-ray, gamma-ray; 47% visible; 45% infrared wavelenghts Earth is cooler, so radiates longer wave energy, mainly thermal infrared. Energy Pathways and Principles Incoming solar radiation is either: Scattered = diffuse radiation Refracted = change in speed and direction Absorbed = raise temperature Reflected = albedo Albedo is reported as the percentage of insolation that is reflected High albedos mean that most radiation is reflected (e.g. over fresh snow). Low albedos mean that most radiation is absorbed (e.g. over wet ground). Effect of Earth’s tilt on solar angle and insolation Latitude of subsolar point (insolation perpendicular to surface) changes throughout the year It is above the equator twice a year (equinoxes) It is above the Tropic of Cancer (June 20-21) and Tropic of Capricorn (December 21-22) once a year Summer solstice: longest days of the year in northern hemisphere Winter solstice: shortest days of the year in northern hemisphere Energy Budget by Latitude Lower latitudes. Higher angle of incoming insolation; day length more or less consistent throughout the year. More energy is gained = energy surplus High latitudes. Low sun angle, light surfaces and great inequality in length of days throughout the year. More energy is loss = energy deficit Earth’s energy surpluses and deficits produce poleward transport of energy and matter in each hemisphere = atmospheric circulation and ocean currents. Atmospheric Profile Atmosphere can be divided according to its: Chemical composition Homosphere (inner atm., well blended) Heterosphere (outer atm., sorted by gravity) Temperature Troposphere (decrease in temp. due to lapse rate) Stratosphere (increase in temp. due to UV absorption by ozone) Mesosphere (decrease in temp.) Thermosphere (increase temp. due to kinetic energy) Function Ozonosphere (absorption of UV by ozone) Ionosphere (absorption of cosmic, gamma, X-, and UV rays)  Stable components of the Homosphere Four main components: nitrogen, oxygen, argon and CO2 Trace elements  Air Movement in the Atmosphere Fourforces act on air movement in the atmosphere: 1. Gravity (gravitational force) Causes the air to press down against the surface of the Earth. Without it, there would be no atmosphere. 2. Pressure-gradient force Rushing of air from areas of high pressure to areas of lower pressure High and low pressure areas exist because Earth’s surface is not heated equally 3. Coriolis force Deflective force cause by the rotation of the Earth Winds deflected towards the right in the Northern Hemisphere, and to the left in the Southern Hemisphere. 4. Friction force Reduces wind speeds at the surface  Factors influencing air temperatures Latitude affects: Sun angle (insolation is more intense between 23.5N and 23.5S) Day length (varies by latitude during the year) Drives patterns of insolation received at Earths’ surface and hence temperatures. Thermal equator: connects all points of highest temperatures  Factors influencing air temperatures Altitude As the atmospheric pressure decreases with increasing altitudes, the air expands. This expansion reduces the collision between molecules (reduces kinetic energy, which results in cooler air) Adiabatic processes refers to the expansion or contraction of air parcels without exchanging heat with the surrounding air. Dry adiabatic lapse rate = 3ºC/100m Wet adiabatic lapse rate = 0.65ºC/100m Factors influencing air temperatures Cloud cover Clouds surface reflect insolation back into space Earth’s surface absorbs less solar heat Cooler during cloudy days Clouds act as insulation Less energy radiated from Earth’s surface escapes into space Warmer during cloudy nights Air temperature in cloudy areas vary less than clear areas Low latitudes with cloudless skies receive more insolation Source: NASA Climate Kids Factors influencing air temperatures Land-Water Heating Differences Land heats and cools much faster than water bodies. Why? … Atmospheric Circulation 3 categories: Global atmospheric circulation Trade winds near equator Westerlies in sub-tropics Easterlies in polar regions Migratory high and low pressure systems Intertropical convergence zone (ITCZ) Equatorial low pressure belt General climate: warm and rainy Polar high-pressure cells General climate: cold and dry Sub-tropical high-pressure cells (e.g., Pacific High) Sub-polar low-pressure cells (e.g., Aleutian low) Tertiary (local winds and weather patterns) Sea/land breezes (caused by the heating of the land and sea) Mountain/valley breezes (caused by the heating of the mountain tops or valleys) Chinook winds (when strong prevailing winds cross a mountain range) Köppen Climate Classification System Abbreviations: A: Tropical; coldest month >18°C; P>E = water P Precipitation; surplus, straddles ITCZ (warm, wet air rising) E Actual Evapotranspiration B: Dry; E>P = net water deficit, in high pressure zones (stable descending air = clear skies = dry conditions) or on leeward side of mountain ranges (in rain shadow) C: Temperate (Mesothermal); coldest month -3°C; at least one month Ta >10°C = strong seasonality, mostly in mid-latitudes D: Continental (Microthermal); coldest month 10°C = allows tree growth, mostly in mid-latitudes E: Polar Climates: warmest month