Final Exam Review GEOG 205 PDF

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Study Sheet Lecture 3 (Climate Variations over time and space) Climate vs. Weather: Weather is short term changes in the atmosphere. Climate is a long term behaviour of the atmosphere. Radiation: energy that is radiated back from the earth is in the infrared part of the spectrum. There is more radia...

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Study Sheet Lecture 3 (Climate Variations over time and space) Climate vs. Weather: Weather is short term (min/months) changes in the atmosphere. Climate is a long term behaviour of the atmosphere. Radiation: energy that is radiated back from the earth is in the longer-wavelength infrared part of the spectrum. There is more radiation at the equator than at the poles because of angle and area of the Earth. The nature of incoming radiation is different than the radiation reflected back. Incoming = shortwave. Reflected = longwave. Clouds play competing roles they absorb and reflect radiation. Albedo: (part of radiation) the % of radiation that is reflected back rather than absorbed. Fresh snow and ice have the highest albedos, water has the smallest. (Water absorbs more heat than snow and ice) Albedo-temp feedback: positive feedback that occurs as a cycle. (Cooling occurs, more snow and ice, higher albedo, more reflection, cooling occurs) At low latitudes: smaller albedos (more absorbed than reflected) ex – equator At high latitudes: higher albedos (more reflected than absorbed) ex – poles. Why are the poles colder? 1) They receive less radiation/square m. 2) They have higher albedos (snow and ice) 3) The angle of incoming radiation is low. (more reflection) Heat: Most of the heat is stored in low latitude oceans. Transfer of heat occurs between water, land and air. Transfer happens through the transfer of “sensible” heat (i.e. heat that you “sense”/feel). Radiation hits the earth, lower air is heated and then rises and the cycle continues. Latent heat = heat that you do not feel, there is no change in temperature, only the release or absorption of energy (i.e. melting and boiling points) Water vapor feedback: positive feedback in a cycle (climate warms, more evaporation, more water vapor, more greenhouse gases, more climate warming) Modes of heat transport: Hadley cell: large scale mode of convection of “advection” which transports sensible heat. Composition of the atmosphere: This is critical to the maintenance of the climate. 1) 2) 3) 4)

21% oxygen 78% nitrogen 0.9% argon 0.1% trace

In trace: 1) 2) 3) 4) 5) 6)

93.5% carbon dioxide 4.7% neon 1.3% helium 0.4% methane 0.08% nitrous oxide 0.01% ozone

Without this, the earth would be 31 degrees colder. The higher the GWP, the more the gas will warm the earth in comparison to carbon dioxide (CO2 is given a GWP – global warming potential – of 1) CFC-12 has the highest GWP. Orographic Influences on precipitation: the warm ocean evaporates and is transported over a mountain, the air cools from 5-9.8 degrees per km in elevation, the precipitation occurs on the mountain side facing the water where crops grow, the other side of the mountain experiences a “rain shadow” where much less precipitation occurs. Air on this side gets compressed and warmed so it can store more water without precipitation occurring. Tropical-subtropical atmospheric circulation: heat goes from low to high latitudes, the heated air rises in the tropics at the ITCZ (intertropical convergence zone) this heat sinks in the subtropics as part of the Hadley cell flow (carries heat away from the equator) rising air in the tropics causes more precipitation than evaporation. Sinking air in the subtropics causes evaporation>precipitation. Low pressure system at the equator because of rising air. High pressure in the subtropics. Seasonal shifts affect the location of the ITCZ. Moves north during northern summer and vice versa. Monsoonal Circulations: in the summer, land heats up faster than water, more evaporation occurs, low pressure occurs, this draws in moist air from the ocean, this causes precipitation over land, high pressure over the cooler ocean. **note that land warms up faster because In the winter, the land cools faster than the ocean, this causes for moist air from the land to be drawn to the ocean: high pressure above land, low pressure above the water, more precipitation above the ocean. **note that land cools faster because of the lack of water present. Coriolis Effect: This is responsible for “trade winds”. The Coriolis Effect makes it seem like air and water is moving to the right even if it isn’t. Wind moving outward from a high pressure cell acquires a net clockwise spin. Air moving toward a low pressure goes counter clockwise. This is the opposite in the southern hemisphere. Coriolis Effect is 0 at equator. Jet streams occur at altitudes of 5-10km in two regions: persistent, weaker

streams near the 30 degree latitude. Mobile jet that wanders between 30-60 degrees latitude above the high and low pressure cells. What is responsible for seasons? Earth’s tilt causes the northern hemisphere and southern hemisphere to point directly towards the sun at some time during the year. The position causes seasonal shifts depending on the amount of solar radiation received at the Earth’s surface. Heat Transfer in the Ocean: Uppermost layer gets heated up by solar radiation. Water expands and becomes less dense so it continues to float. Winds help warm the lower parts of the ocean up to 100m in depth by mixing the upper, warmer layer with the lower ones. Spinning gyres occur in response to a push and drag of the winds on the ocean’s surface.

REVIEW QUESTIONS (most likely on exam) 1. What is the difference between weather & climate? Weather is the short term change in the atmosphere (over days or months) and climate is the long term change in the atmosphere (many years). Climate looks at the change in daily weather for long periods of times. 2. Why are the poles colder than the rest of the earth? First of all, the poles receive less solar radiation because of their position on Earth’s spherical surface (they are furthest from the sun and at an angle where there is less solar radiation/square meter). Secondly, the surfaces in the poles are mostly snow and ice, both with very high albedos (most reflection of solar radiation), therefore heat is not absorbed there as well as the equator or other latitudes. Lastly, the angle of the incoming solar radiation is lower because of their position on Earth. 3. Why are there seasons? The seasons are caused by the Earth’s tilt. The tilt of the earth (about 12 degrees) causes the two hemispheres to point directly toward the sun at a certain moment during the year. The northern hemisphere points toward the sun during the northern summer (june-september) and the southern hemisphere during the southern summer (December-february) 4. What are the solstices? There are two solstices, the winter and summer solstice. The winter solstice is the longest night of the year and shortest daylight time (for the northern hemisphere it is December 21st). This occurs when the Earth is tilted away from the sun the most. The summer solstice is the longest daylight time and the shortest night time (for the northern hemisphere it is june 21st) which occurs when the Earth is titled most toward the sun. These dates are opposite for the southern hemisphere. 5. What is sensible heat, latent heat and albedo (how does albedo vary with angle and type of surface)? Sensible heat is heat that we can “feel” or “sense” that travels with air. Sensible heat is what is transported. Latent heat is when there is no temperature change, but a release or absorption of energy (this is usually the

boiling point or melting point of an object). Albedo is the percentage of solar radiation that is reflected by a surface. Albedo depends on the type of Earth surface (snow and ice having the greatest albedo and water having the smallest). It also depends on the angle of solar radiation. If the angle is low, there will be more reflection, if the angle is large (90 degrees being the highest) it will reflect less. 6. In what form is radiation incoming from the sun and in what form is it re-radiated? Short wave radiation is received by the Earth’s surface and long wave radiation is reflected back. 7. Can you explain what controls the absorption and reflection of these two forms of radiation? The sun sends solar radiation towards the Earth, the clouds absorb some of it, and reflects some back, the Earth’s surface absorbs some of it and reflects some back. The nature of the surface of the earth will change the amount that is reflected or absorbed (albedo) and so will the angle of the solar wave. When the long wave radiation is reflected, it hits the clouds and the greenhouse gases. These greenhouse gases are meant to trap long wave radiation (and not shortwave, which is why the solar radiation can pass through the atmosphere). The greenhouse gases trap some of it and return it to the Earth to warm its surface (without this, the Earth would be 31 degrees colder). 8. What roles to clouds play in radiation receive or lost? Clouds play a competing role as they can absorb and reflect solar radiation. 9. Can you sketch Hadley cells and explain what happens to temperature and precipitation of air masses as they move through these cells? The hot air in the tropics at the ITCZ (intertropical convergence zone) rises and moves towards higher latitudes (the subtropics). As the air moves higher up in altitude, it cools and sinks in the subtropics. Because of the rising in the tropics, there is a low pressure system there which causes more precipitation in the tropics than evaporation (cloudy skies). The sinking air in the subtropics causes a high pressure system there and causes the evaporation to be greater than the precipitation (cloudless skies). 10. What are some important greenhouse gases and how does their global warming potential vary? Carbon dioxide is important, and is used as reference to determine the GWP, therefore it has a value of 1. There is methane and nitrous oxide that are also important, both with GWPs that are greater than carbon dioxide. Methane has a smaller GWP than nitrous oxide, but the greatest one is CFC-12.

11. What is the ITCZ how and why does it shift? This is the intertropical convergence zone where the Hadley cells transport heat from the equator to lower latitudes. This is where the trade winds converge. This ITCZ moves towards the northern hemisphere during the northern summer and the southern hemisphere during the southern summer. The ITCZ follows the sun’s zenith point (when it is exactly 180 degrees from the Earth’s surface) 12. Can you explain the Coriolis Effect? The Coriolis Effect is what makes the air and water on the Earth’s surface to appear to be moving to the right when it is in fact not. This is an inertial force that is caused by the Earth’s rotation which makes it look like objects in a straight path are being deviated to the left or to the right. Wind moving away from a high pressure system moves clockwise and wind moving towards a low pressure system moves counter clockwise (opposite in the southern hemisphere). 13. What is orographic precipitation? When warm air from the ocean rises and moves toward a mountain, the air rises to higher altitudes and is then cooled. This causes clouds to form and thus heavy precipitation on the upwind side of the mountain. The rest of the air has to rise more because of the elevation of the mountain and is compressed. The air is able to compress without causing condensation (or precipitation) and this creates a rain shadow where there is very little precipitation on the other sides of mountains. 14. Can you describe what creates summer and winter monsoons? In the summer, the land heats up more quickly than the oceans. The specific heat of water is high compared to soil and other land surfaces. This causes evaporation to occur over land and thus creates a low pressure system. The low pressure draws in moist air from the cooler ocean and precipitation occurs over land. There is a high pressure above the oceans. In the summer, the very opposite occurs. The land cools much more rapidly than the ocean (because of its low heat capacity) and the ocean is thus warmer than land. Hot air rises above the ocean creating a low pressure system and the sinking air above land creates a high pressure system. Therefore there is more precipitation above the ocean during the winter.

Lecture 4 (Biomes) Photosynthesis: plants converting carbon dioxide into oxygen. The opposite is respiration, which is what all animals do (take in oxygen, produces carbon dioxide) Food Chain: primary production (plants) secondary production (animals) and decomposers (microbes, worms, termites) Biomes: a large terrestrial ecosystem characterized by what plant communities and formations are present (usually named after predominant vegetation). This varies with temperature and precipitation. Latitude and altitude affect the climate and vegetation.

Important biomes: Tundra, Boreal Forest, Temperate Deciduous Forest, Dry Woodlands and Shrublands (Mediterranean or Chapparal), Desert (warm and cold, semi-desert), Tropical Rain Forest, Temperate Grasslands, Tropical Savanna Estuary: Where an ocean and a river mix. Salt Marsh: Type of wetland that is flooded with salt estuarine water. Desert Biomes: little precipitation, little vegetation. Evaporation>Precipitation. Covers 30% of the Earth’s surface (mostly tropical and subtropical). Found far away from the sea (middle of continents). Land there heats quickly during the day and cools quickly at night. Tropical Deserts: Hot and dry most of the year. Few plants, hard windblown surface strewn with rocks and some sand. Temperate Deserts: Daytime temps are high in summer, low in winter. More precipitation than tropical. Vegetation is widely dispersed with drought-resistant shrubs and cacti that are adapted to lack of water Cold Deserts: winters are cold, summers are warm. Precipitation is low. Semi-desert: zone between deserts and grasslands. Dominated by thorn trees/shrubs that are adapted to long, dry spells followed by brief heavy rains. Plant adaptations for low precipitation: Some drop their leaves to survive in a dormant state (Mesquite and Creosote). Some have no leaves so they can’t lose water as much, they can store water and synthesize food in fleshy tissue and they can reduce water loss by opening their stomata (water pores) to take up carbon dioxide at night only. Some use really deep roots to tap into groundwater. Some use shallow, widely spread roots to collect the most water after brief showers (prickly pear and saguaro cacti). Some have wax-coated leaves to lose less water (evergreen plants). Flowers store most of their biomass in seeds that remain inactive. Animal Adaptations: most are small, most hide in cool burrows or rocky crevices during the day. Some become dormant during droughts and extreme temperatures. Insects/reptiles have thick outer coverings to minimize water loss (waste is also dry). Spiders and insects get their water from dew in the morning and from the food they eat. Grassland, tundra and chapparal biomes: can be called prairies, have enough precipitation to support grasses and very few trees. Found in interiors of continents. There are seasonal droughts, grazing by animals and occasional fires. Low average precipitation and many average temperatures. Tropical grasslands and savannas: savanna has warm temperatures year-round, two dry seasons and abundant rain the rest of the time. African tropical savannas have enormous herds or grazing and browsing herbivores. Animals have evolved methods of eating (giraffes eat at the top of trees, elephants at the bottom etc).

Temperate Grasslands: good weather and soil for crops and livestock. Cover vast expanses of plains in the interiors of North and South America, Europe and Asia. Winters are very cold, summers are hot and dry. Precipitation is sparse and falls unevenly through the year. Rich fertile, soil. Good place to grow crops. Polar grasslands/arctic tundra: bitterly cold. Covered with ice and snow (except during a brief summer) occurs south of the polar ice cap. Treeless. Scant precipitation falls as snow. Spongy mat of low-growing plants (grasses, mosses). Permafrost occurs here (frozen layer of the soil that forms not far below the surface when the water freezes). This creates shallow lakes, marshes, bogs, ponds. Mosquitoes, blackflies and others thrive in these conditions. Small herbivores live here (lemmings, hares, voles) and hide underground to survive the cold. Thick coats on most animals. Decomposition is slow (because it is cold) soil is poor in nutrients. Chapparal/temperate shrubland: wonderful climate but subject to massive forest fires in the fall. Longer winter, rainy season. Low growing evergreen shrubs and small trees (leathery leaves) to store water. Shrubs keep food reserves in their fire-resistant roots to sprout after fires. After rain, wildflowers spring up and use the nutrients released by the fire. Forest Biomes: enough precipitation to support vegetation. Various species of trees and smaller forms of vegetation. Tropical rainforests: Very high diversity. Heavy precipitation, very humid. Warm temperatures. Broadleaf evergreen plants with shallow roots and wide bases to support their weight. Tops of trees block sunlight, so plants near the ground have large leaves to get the most sunlight. Rapid recycling of nutrients. Most animal life is found in the sunny canopy. Temperate Deciduous forest: plants drop their leaves and produce a nutrient-rich soil. The forests change dramatically during seasonal changes. Long warm summers, cold winters, abundant precipitation evenly spread out. More sunlight but less species than rainforest. White tailed deer, squirrels and raccoons found. Evergreen Coniferous forests/boreal forest: Cold temperatures. Cone bearing evergreens that keep their needles. South of the arctic tundra. Summers are short, mild to warm temps. Spruce, fir, cedar and pine are found. Flexible branches and shape help the trees rid themselves of snow. Plant diversity is low because of the winters. Decomposition is slow (cold). Aspen parkland: transition zone between the boreal forest and the grasslands. Grassy openings with scattered trees. Temperate rainforest: Huge cone-bearing evergreen trees. Cool and moist environment. Lots of rainfall. Tree trunks and the ground covered in mosses and ferns. Little light on forest floor. Winters mild, summers cool.

The classic paradigm: natural systems with humans disturbing them. Classic biomes: f(C,E,G) = climate, terrain, geology. Sustainable management of the biosphere is based on reducing human influences. The anthromes paradigm: human systems with natural ones embedded in them. Anthromes = f(P,T,A…X?): population, affluence, technology, unknowns. Most of the biosphere is reshaped by human systems. REVIEW QUESTIONS: 1. Locate each biome on a map. Polar ice cap is at the top. Arctic tundra is south of it in northern Canada and Russia. Boreal forest is in northern countries (bottom of Canada and Eurasia). Tropical rain forest is found in costa Rica (central America), Brazil, west Africa. Temperate grasslands are found in central USA and East Central Asia. Deserts are found in the west (WILD WEST TRICK) of the US, the North of Africa, Mid-West Australia and scattered in Asia. Temperate Deciduous and rainforests are found in western Europe and Eastern US/Mexico. Tropical Deciduous Forest are found in the South of Asia and near Costa Rica and Panama. Chaparrals are found just above the desert in Africa and under the desert in Australia. Tropical grasslands and savannas are primarily found in Africa and Tropical shrubs are found surrounding the savannas. 2. Can you provide an example of each? Can you recognize examples of each? See question one for examples of each in countries/continents. 3. What types of vegetation is dominant in each? (note the names of some plants) In the arctic tundra there is very little vegetation, mostly mosses and dwarf plants. The boreal forest has cone-bearing trees (pines, evergreens). In grasslands there is mostly just grass. In the desert, there is cacti, wildflowers, all plants that have adapted to droughts and high/low temperatures fluctuations. In the savanna there is mostly tall grass and scattered trees. The tropical rainforest has a very high diversity with many tall trees with broad leaves. In the temperate deciduous forests and rainforest the vegetation drops their leaves during seasonal changes...