Study Guides (238,072)
Canada (114,906)
Geography (252)
GEO 605 (16)

012113 The Physical Geography of the Canadian Arctic.doc

10 Pages
Unlock Document

Ryerson University
GEO 605
David Atkinson

GEO605 Geography of the Canadian North 012113/012813 The Physical Geography of the Canadian Arctic ARCTIC CLIMATE • The basis of the north is its climate • Land of the midnight sun o The sun shines at midnight during the summer above the Arctic Circle  In the summer, the sun never sets; in the winter, the sun never rises  Positions of the sun and the earth: summer solstice, autumnal equinox, winter solstice, vernal equinox  As you move away from the equator, you get the concept of longer days/longer nights o 66.5 degrees N latitude o At 70 degrees N, the sun sets in November and doesn't come back until mid January • Extremely cold temperatures o A lot less solar radiation (even with 24 hours of sunlight in the summer)  When the sun shines, we get the same amount of energy but due to the tilt of the earth, solar energy has to cover twice the amount of land for the same amount of energy  Even with long sun days, there is not enough energy to cover the land o 2 months of the year (July and August have average daily temperatures above freezing (0°C) o In Toronto, 2.5 months are below freezing (0°C) o In Orangeville, 2 months are below freezing (0°C) • Very little precipitation o Less than 200mm (Toronto gets about 900mm) o Most of which is snow in a frozen state for most of the year • Very windy o Warm air rises off of the land and cold air (cold front) fills the void ELECTROMAGNETIC (EM) RADIATION • Electromagnetic radiation varies with wavelength/frequency producing different properties of energy – the Electromagnetic Spectrum o Earth absorbs solar radiation and slows down the energy and becomes infrared heat (thermal radiation) o Our atmosphere is made of chemicals which absorbs different portion in the spectrum  If black, has 100% absorption o Atmospheric window (white) which allows visible light to pass through ATMOSPHERIC STRUCTURE • Layers (from surface) due to: o Density (pressure)  Different portions of the spectrum goes through the atmosphere o Radiation environment  Atmosphere acts as a blanket that keeps the heat in  The more greenhouse gasses we add into the atmosphere, the more heat we keep in the atmosphere o Temperature ABSORPTION OF TERRESTRIAL RADIATION • Water vapor: is an excellent absorber of terrestrial radiation in wavelengths of less than 7um • Carbon dioxide: is an excellent absorber of terrestrial radiation in wavelengths longer than 12 um o Level has been increasing because of burning fossil fuel GEO605 Geography of the Canadian North o Concentration in the atmosphere is rising  Annual cycle increases in May and June, but decreases in the fall  Plants that grow take in carbon dioxide in the photosynthesis process; in the fall, the plants release the carbon dioxide which further increases carbon dioxide concentration in the atmosphere o As of January 2013, current carbon dioxide level is 393.55ppm • Methane: is an excellent absorber of terrestrial radiation in wavelengths of near 7um • Human activities have changed the composition of the atmosphere since the pre-industrial ear o Carbon dioxide, nitrous oxide, methane, and sulfur are the four components that makes the atmosphere thicker GREENHOUSE EFFECT • Greenhouse effect: the absorption of terrestrial radiation by the gases in the Earth's atmosphere o Solar radiation easily passes through the glass in the greenhouse o Solar radiation is absorbed and stored as internal energy inside greenhouse increasing the temperature  Temperature in the glass house stays warm o Terrestrial radiation is by the glass and the energy stays inside the greenhouse o The walls and sides of the greenhouse keep the cooler outside air from missing with the warmer air inside the greenhouses • Roughly half of the solar radiation passes through the atmosphere and is absorbed by the Earth's surface • Approximately 86% of the terrestrial radiation emitted by the surface is absorbed by gases in the atmosphere and only 14% escapes to space o Energy balance is the measurement of energy going into the earth and the amount of energy that comes back out • The Earth's greenhouse effect occurs when terrestrial radiation emitted by the surface is absorbed in the atmosphere and then is radiated back to the surface as terrestrial radiation emitted by the atmosphere o Income solar radiation from space causes terrestrial radiation reaching space o The terrestrial radiation is absorbed by the atmosphere and some terrestrial radiation emitted by the atmosphere back to the surface of the Earth ATMOSPHERIC STRUCTURE • Increasing CO2, Methane • Increases density of the atmosphere • More GHG is absorb Thermal Infrared Radiation WHAT IS CLIMATE CHANGE? • Climate change not necessarily Global Warming o The poles are where we see majority of the changes; temperature at the equator stays relatively the same  Global warming is an AVERAGE measurement (some areas have warmer days and others have cooler days) o Climate has always changed; it is not equally balanced in the globe o The Arctic has been much warmer and cooler in the past • Huge increase in Anthropogenic Carbon Emissions since the Industrial Revolution • Atmospheric carbon changes our atmospheric windows o Long wave radiation (heat) cannot escape • Some feel that the changes we are seeing are natural fluctuations GEO605 Geography of the Canadian North o Solar cycles and micro-orbital shifts o That is not enough though to account for the rate of change o Ozone absorbs more ultraviolet HOW DO WE KNOW THE CLIMATE IS CHANGING? • Direct measurements o Temperature measurements  Temperature trend is continuously increasing • Proxy measurements o Estimations of past climates based on indirect evidence  Paleo-climatoloty: study if indirect evidence of climate change  In glaciers, there are pockets of frozen air that can be used to measure the temperature o Ice cores  Trap gases and show past concentrations  Date the age of the ice based on isotopes o Sediment cores  Varves (layers of soil/mud) measured based on sediment thickness/depth  Carbon dating  Diatoms are plankton and other microorganisms in the water • Each band of dark and light represents layers of years to tell the difference based on the skeleton remains • Increase in certain species that didn’t exist in the past because temperature in the water is becoming warmer CONSEQUENCES OF CLIMATE CHANGE • Land surface o Permafrost degradation o Vegetation shifts • Wildlife o Change in habitat • Sea ice o Reduction in cover and changes to patterns o Reduced Albedo • People o Change in lifestyle WHAT IS TUNDRA? • Tundra is from the Finnish word "Tunturia" (treeless plain) • Alpine (high in latitude) and arctic tundra (high in elevation) • Both are defined by the extent of the treeline o Treeline is the boundary where for climatic reasons tree's can no longer grow normally • Youngest Biome is only 10,000 years old • Tundra is characterized by: o Extremely cold climate o Limitation on drainage o Short season of growth and reproduction o Low biotic diversity o Simple vegetation structure o Energy and nutrients in the form of dead organic material GEO605 Geography of the Canadian North o Large population oscillations PERMAFROST • Permanently frozen ground o The Arctic takes more carbon than they use to because some plant materials trapped and thaws out carbon dioxide • Continuous (everywhere) or discontinuous (patchy) • Treeline also defines the continuous permafrost line o Tree roots cannot grow in continuous area where roots do not grow deep • Active layer thaws in the summer • Depth of the active layer depends on many things o Vegetation o Summer temperature o Soil type PERIGLACIAL ENVIRONMENT • Describes a suite of processes dominated by freezing and ice formation and the landforms that are created and affected by these processes (created near glaciers) • Key is repeated freeze thaw cycles LANDSCAPE SHAPED BY ICE AND FROST • Ice wedge polygons o Cracks are formed because it is too cold o In the spring, the crack is filled with water and then freezes again in the winter o Expands and contracts the soil to create different shapes o Vegetation only in the cracks because of moisture and more nutrients in the loosened soil • Flat ground • Gentle slope • Sloped surface • Frost shattering o When water freezes it expands 10% o Water seeps into cracks, joints, and bedding planes in rock, freezes, and splits the rock • Frost heave o Soilfluction lobe where soil is flowing downhill because it is freezing and thawing o When the ground freezes, it expands • Monument stones o More vegetation around the rock because more nutrients from animals in the life cycle (sudden changes in landscape have big effects) o For example, owls hunt and carry food to monumental rocks for feeding and dropping owl pellets around the monument • Mud boils o Two possible causes: more moisture and take longer to freeze which pushes mud to the top OR permafrost melts • Snow and snow melt o The perception that falls happen in the winter o Melt water from the snow gets redistributed is what “kicks off the system” o When melted, it is rapid, where stream channel flows on top of the land o Snow accumulates in a valley is where the river was flowing in the earlier season • Erosion o Because of more perception and permafrost melt GEO605 Geography of the Canadian North o Stream is undercutting the bank (cave like) where stream undercuts permafrost which begins to slump off because soil and vegetation is held up by ice DRASTIC LANDSCAPE CHANGES • Changing weather (including major rain event) with mix of conditions: permafrost melting affecting the soil and precipitation adding moisture • Removes vegetation from movements RIVER AND SEDIMENT MONITORING • Monitor and measure amount of river flow to measure amount of sediment in the system and the water RAISED BEACHES • Concentric rings along the Arctic Ocean which is a ridge to a lower level • Each ridge line was part of the beach o Sea level has not gone down; land has moved upward o Land was glaciated which presses the land down o When weight is removed the land moves back up; referred to as isostatic rebound • Land is rebounding at the same rate in the arctic • Evidence of arctic people with camp sites with age and estimation of the historic date PINGO'S • Hills form on tundra because of permafrost (around Mackenzie Delta) • Wet land area with a hill that is dryer and the higher up is winder o Less insects but attracts other wildlife because of elevation that reduces chances of flooding • Inside the Pingo is an ice core ESKERS • Landform on landscape that changes from elevation • Caused by glacier; when melting created river bringing along sand and gravel which gets deposited along the ground o It is old rivers within the ice o Water inside melts and the sand and soil settle down to create the land elevations • Importance is the elevation running along several kilometers o Becomes traveling ground for wildlife and hunting ground because if dryer area o Aboriginal camps are set up on the ridges o Important ecologically and culturally o Helped with the discovery of diamonds • Important to industry with the discovery of diamonds NUTRIENT CYCLES • Because of industrial, level of carbon dioxide is increasing VEGETATION • Very short growing season - June to mid August o Nutrients important to cycle o Water provided by snow melt o Veget
More Less

Related notes for GEO 605

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.