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Department
Geography
Course
GG101
Professor
William Bill Quinton
Semester
Fall

Description
Geography – Solar Energy & Seasons 10/15/2013 8:19:00 AM Lecture 2 – Sept 13, 2012 Solar Constant Short (hot) wave and long (cold) wave radiation Solar Constant = amount of energy arriving at the outer edge of our atmosphere 1400 w per square meter Function of distance from sun What controls amount of E reaching the atmosphere Geometric relationships between earth & sun Atmospheric filtering = Energy filter, filters & reduces the amount to Energy so the solar constant is reduced greatly Earth revolves around sun but rotates on its axis … controls geometric relationships Sub solar point = position on earth where sun is directly over head … 90 degrees on horizon Never gets to waterloo, 23.5 degrees south to 23.5 degrees north then back down to 23.5 degrees south 23.5 is the angle of the axis of rotation Equinox = equal illumination on both hemispheres December solstice, the north pole has 24 hour darkness and the south pole has 24 hour light Summer solstice, winter solstice and two equinox positions (fall & spring equinox are identical) Circle of illumination is the same for the 2 equinoxes … cuts right through the middle Geometric relationships Control position of sub solar point & therefore the angle of incidence (angle that solar ration strikes surface of the earth) of radiation Angle of incidence is important because the energy flux density is lower … still 9 volts but spread out over a bigger surface If we had no tilt we would not have seasons but would still have day & night Earths tilt is a very important mechanism of spreading energy Summer solstice = 23.5 degrees north is the sub solar point Winter solstice = 23.5 degrees south is the sub solar point How does the amount of solar radiation vary over the day, and over the year at a single point on the earth’s surface? 54k Lecture 3 – Sept 18, 2012 What controls amount of solar radiation reaching the Earth? 1. Distance from the sun Drive solar constant (1400 w of energy) 2. Geometric relationships between the earth & sun Tilt of earths axis (23.5 degrees) Fact Earth rotates around the sun Fact Earth rotates on an axis 3. Role of the atmosphere What controls Angle of Incidence? Latitude Time of day Time of year Solar Energy to Earth & the Seasons Nature & Forms of Radiation Describes light & heat Units are in micron (millionth of a meter) Wavelength is controlled by temp of radiating surface Heat = short Cold = long Laws Governing Energy Flows Gradient = flow, small gradient = small or short flow … large gradient = large or long flow Amount of radiation moving through a medium must move through 3 things: Transmission Absorption Reflection Laws Describing Radiation from Surfaces Weins Law Hot objects emit short waves, cold objects emit long waves Wavelength of maximum equals the constant divided by the surface temperature Absolute 0 = 273 k Stefan-Boltzman Law Increase temp of surface a bit and the amount of energy coming off of it increases a whole lot Solar & Terrestrial Energy Weins law explains why they are horizontally separated Stefan-Boltzman explains why they are vertically separated Budgets of Radiation & Energy Energy is a channel as it makes its way through the atmosphere How does solar radiation pass through the atmosphere, interact with it & the ground surface? The Atmosphere as an “energy filter” Forcing energy through one of the 3 channels (equation) Atmosphere is a blanket, supplying energy to earth as long wave radiation T = shortwave radiation that made it through atmosphere Alpha = shortwave radiation that does not make it through the atmosphere A = Comes in as short wave and leaves as long wave 1400 at top of atmosphere, but when we get to ground it is less than 1400 (300 or 400 or 500) Scatters short wave radiation (no sunsets if it didn’t scatter them) Diffuse = scattered short wave radiation Direct = sun has to be up No atmosphere, no filtering (comes in as 1400, gets to ground still with 1400) Atmosphere Scattering Characteristics of Atmosphere Stratified by its mass … therefore, mass of atmosphere is within 30 km of the earth surface How does “atmospheric filter” vary with time? Changes over time & space Time variations Insolation at Earth’s Surface The equator doesn’t have the highest radiation b/c it is an area of convergence, and is usually always cloudy, therefore not letting a lot of radiation in and the actual high radiation area has most of the time clear sky’s, allowing tons of radiation to flow in Lecture 4 – Sept 20, 2012 Radiation & Energy Balances Albedo (alpha) – “tax man” Ratio of amount of radiation reflected by a body to the amount incident upon it How does it vary over space? Very high for light surfaces & low for dark surfaces Asphalt is 5-10% radiation, leaving us 90% of the energy coming in to put to work (processes) How does it vary over time? Snow will get darker & albedo will change Forest will lose leaves & albedo will change During winter it will intercept snow & increase albedo Translucent surfaces are good transmitters, opaque surfaces are bad transmitters What ever is lost by albedo is put to use at transmitting … we have a lot for absorption Darker surfaces are better at absorption because it doesn’t reflect Ex: lighter house over darker house Radiation balance Albedo controls how much comes off (how S up is larger than s down) Energy balance Depends on being fed by the radiation balance Phase Changes of Water Release Latent Heat Condensation 25oo J/g Deposition Mix of condensation & freezing 2834 J/g Freezing Releases 334 J/g Absorb Latent Heat Evaporation 2500 J/g Sublimation 2834 J/g Melting Absorbs 334 J/g Day-time & Night-time fluxes Left feeds the right K is the same as S* Right – energy balance Net amount of energy is equal to … (Q*) Energy moves from surplus to deposit Night – surplus of energy is not at surface but below it and above it L down is energy supplied by atmosphere Flow of energy must be away from surplus area (second night diagram) No sum = no short wave coming in so no short waves coming out Non radiative fluxes are plotted as positive if they are directed away from the surface Very little water supply .. very dry, therefore Qe is very low, Qh & Qg are very high … quite hot Qe is high, needs less energy to heat ground & air bellow, so very cool environment Lecture 5 – Sept 25, 2012 Partitioning of Solar Radiation Q* = S* + L* Q* = 48 + (- 16) ----- from 97 – 113 Q* = 32 Q* = 32 goes over to outgoing as heat … 22 goes to latent heat transfer & 10 to sensible heat transfer Energy Balance Q* = Qe + Qh + Qg +/- delta S(changes in energy storage) or delta Qs Flux Convergence & divergence - delta S = cooling, + delta S= heating A) Accumulating Energy Flux Convergence B) More energy leaving then coming in Vertical flux Divergence C) More energy going out then going in Horizontal flux divergence Ground Surface as a source of heat Solar radiation – no sun, no energy .. it drives all processes Diagram on paper First ground is heating the air – going from surplus to deposit Energy flowing away from surface = Qh Flipped it represents Qg (Ground heat flux) Global Temperatures Profile of the Atmosphere Troposphere – top of it is tropopause Its thickness varies .. thinnest a poles & thickest at equator Polar Tropopause & Equatorial Tropopause Where most atmospheric water is Where most atmospheric arousals are (smoke, smog, viruses, bacteria etc.) Very small Major players in scattering of incoming solar radiation (brightens sky) Very important for precipitation, provide a source for the condensation to sit on … condensation nuclei Stratosphere Strong persistent winds Little mixing between air of troposphere & stratosphere Very little liquid & very few nuclei arosals The ozone layer Lecture 6 - Sept 27, 2012 Fill in the blanks and multiple choice – QUIZ ON OCTOBER 11, 2012 He will put on practice questions … two of them will be on the QUIZ Temperature profile Temp is responding to temp of ground heat Atmospheric Composition Heterosphere – Couter atmosphere Relativily thin From 80 km outwards: same as Thermosphere Layers of gasses, sorted by molecular weight of gas moleclues Homosphere Surface to 80 Km Gases evenly blended Atmospheric Pressure As you increase your elevation in the air, the more spread out the particles get There is more pressure on the ground, the density of the molecules is increased … as you get higher the density decreases Gas is compressible therefore under its own weight it compresses Most of the mass is within the Troposphere Red line in diagram Temperature Scales Measure of the amount of molecular activity Celsius based on boiling or freezing point of water Relative scale Absolute temp is -235 is absolute 0 .. no molecular activity at that temp & is 0 kalvin Thermometer & Instrument Shelter B) Stevenson screen 2.1 m above the ground Ventilated and inside there are a thermometer and some more instruments A) Temp sensor inside the shield Protecting them from direct sunlight Well ventilated enclosure 1.2 m variation of temp at different heights Air Temperature Measurement The normals Based on thirty year period of observation Normal Min 30 Oct 11 thto work out an average min temp … do it for all the days to get the line, vice versa for average max temp Take the coldest days on the day and average them to get the extreme min .. vice versa for hottest days Temperature Profiles Vary over the Day Air abouve and ground below follow what ever the surface is doing Change in temp profiles over a course of a day Air Temperature Global Factors Latitude (annual cycle of Q*) Time (of day and of year) Local/Regional Factors Elevation Proximity to urban areas Proximity to large water bodies (great lakes, oceans, seas) Downwelling of S down (shortwave incoming can move down through a water body) Thermal properties (timing of max Ta) (takes more energy to warm up some materials than others, so some materials move up more slowly then others) Mixing of energy (when lakes warming up during day, mixing or convection develop, cold water sinks, warm water rises … mixing water … surface cooler and things get mixed around all over the place) Evaporative cooling (moist surface) Global Factors As you go down, your distance from the equator is increasing Closer to equator seasonality is decreased, but as you get farther, you get more seasons How are S down & Q* & Ta Related? IMPORTANT S down = Incoming short wave radiation (no negative values) Three lines representing the equinox lines Drives all processes , Q* = net alwave radiation, Three lines representing the equinox lines Ta = temp min is just before sunrise, max daily temp is to the right Four lines … 2 equinoxes Takes time to warm air up .. therefore spring equinox would lower, accumulated energy in the fall equinox Takes time to gain energy, takes time to lose energy Oct 2, 2012 Time Lag in Response of Ta Provides surplus of energy Local/Regional Factors: Elevation Density of temperature Why does elevation influence Ta? Temp drops off about 10 degrees per km Middle line is average for every month Low density on the right side Cleaner air Closer to the top of the atmosphere Atmospheric mass is close to the surface High density on the left side Less filtered Local/Regional Factors: Proximity to Urban Areas Cities are designed to whisk water away through drains .. therefore not a lot of water Much less evaportation in the city, where more in the rual because of more water Rual enviroments are cooler Cities are made of highly reflective materials Pollution, absorb one wave making cities a bit warmer (Green House Gases) Phase Changes of Water Release Latent Heat Condensation (25oo J/g) Deposition (2834 J/g) Freezing (334 J/g) Absorb latent heat Evatporation Sublimation Melting (334 J/g) Urban-heat island Effect of proximity to urban areas Local/Regioanl Factors: Proximity to large water bodies A lot more evaporation on the water surface Marine & Continental Climates in Canada Vancouver is closer to a bigger body of water Greater continentality (seasonality) for Winnipeg than Vancouver Global Mean January Temp Air from southern hemisphere’s is coming together and rising Thermo equator rises and goes pole ward (northern & southern pole) Isoclines bend southward in the continent .. some cold air coming in from the northern parts Global Mean July Temp A lot warmer conditions B/c takes so much longer for the ocean to warm up and cool down Polar Mean January Temperatures North Pole (Winter) -36 South Pole (Summer) -30 Polar Mean July Temperatures North Pole (summer) South Pole (Winter) -66 Rule out global factors to explain diff in temp South pole is thousands of km from any ocean, north pole is in the middle of an ocean South pole is in a mountain range (km above sea level) North pole is at sea level (doesn’t influence colder temp) Oct 4, 2012 Winds & Atmospheric Circulation Not our motion, the atmospheres Atompsheric pressure Differential pressure is caused by differential heating of the surface Pa is generally used Changes in pressure Composed to gases & gases are compressible … it will compress & pressure will be greater to ground surface & atompshere is denser as a result Wind Vane & Anemometer Anemometer Hooked up to data loger(computer that can take averages and so on) Barometers Used for atompsheric pressure The amount of pressure pushing down on surface will cause mercuty to rise up tube .. more pressure the higher mercury will go Measure mercury for changes in atmosphere Air Pressure Scales Atompsheric pressure is between 980 & 1050 mb Air pressure is greatest at sea level How does atmospheric pressure change with elevation? Not a linear change b/c atmosphere changes/compresses under its own weight Most dense at lower elevation, less dense as you get higher up (less mass above you) Water is incompressible… therefore under sea level it would be linear Factors Influencing the Wind Pattern Pressure gradient from high to low pressure … no pressure gradient you have no motion in atmosphere The motion occurs, there are 2 other forces Coriolis – deflection of wind direction b/c the earth is rotating Increases with wind velocity Friction – reisitance to flow Greatest near surface b/c its imposes more resistance to flow Velocity increases as you go up Geostrophic wind – highest you can go while the wind is still affected by the surface The height of it, the wind direction is parallel to the isobars Moves between high pressure & low pressure Four Atmospheric Lifting Mechanisms: Differential heating We need a lifting mechanism B) convectional heating Different energy balance (Qh) Middle is heating up (could not be irrigated), while fields are staying relatively cool Air in the middle will warm up H – L – H Air will expand and become unstable as it is less dense .. it will rise & air moves in to fill void Differential Heating Gound surface is warming & as a result we get a “bubble” developing .. air is expanding & becomes unstable and starts to rise It will detach itself from the ground & air rushes in following the lines moving from surplus to deficit .. experience it as wind Local Winds Day Island is heating up, surface of water remains relatively cool Differential heating now, and differential pressure follows Warm air rises & expands, air rushes in from water Nights High pressure is over island Reversed what is relatively high pressure & relatively low pressure .. the winds have too Winds moving from island out to sea Above every air surface low there is a high and vice versa Lines are isobars – lines of equal pressure Pressure Gradients Cells of high pressure & low pressure are the green lines It changes The rate at what they move depends on the gradient of H or L Non-rotating, Uniform Planet Corilois depends upon rotation of earth Low pressure results from air being less dense & moving pole ward Air is denser & moves equator ward from the poles One big bowling ball, not continents or oceans Rotating, non-uniform planet Hadley cells – originate at equator where air rises (intertorpical convergence zone) pole ward but doesn’t get to pole b/c of high pressure cells developing around tropics of cancer (deflects to right or left) Descend at topics because the rate that the earth is spinning Air descends equator ward but not at a straight line … squiggles a little bit Rotating planet Coriolis affect The arrows are not straight lines Oct 9, 2012 Coriolis Force 2 different velocities at any place on the planet Actual velocity Ex: A lot higher in new york than the rocket originated Going away from equator decreases Going towards the equator it increases Angular velocity Rotations appears to be from left to right Ex: if you send a rocket from the NP to New york .. the rocket will land in Chicago because the earth is spinning and the rocket got deflected When she sends it back, going away from the equator, the actual velocity gets slower, it ends up to the right of the NP b/c it shifted at a higher rate, due to the velocity Going west to east, the planet is moving west to east as well, so as it is a curved surface, you will not get to new york again, you will get to where it was earlier in the day, it has moved since then If earth was a cylinder and not a sphere, there is no curvature, so you would land at one point to the next, no deflection Increases with velocity Pressure Force Air is moving from high to low Pressure gradient develops Straight line so no defelction Coriolis Force Combined forces of the 2 results in the geostrophic wind Goes around and around and around Friction Force 0 at top of wind profile always counter to wind direction mean direction of wind will be toward the low but to the right of it Deflection of Winds Defelct low to right Corliolis force increases with elevation Corilous is becoming more and more powerful & is getting to a max Wind direction is being bent away from directly to the low First graph is in the southern hemisphere Second is in the northern Deflecting to right, increasing with elevation Wind flow is parallel to isobar Over globe, the corliors increase the further and further you get away from the eqator At the equator the corilious effect is 0 Cyclone: Center of Low Pressure with in-spiralling air Anti-clockwise in N.hemisphere (since Coriolis defelction is to the right) Clockwise in S. hemisphere (since coriolis defelction is to the left) Anticyclone: Center of High Pressure with out-spiraling air Clockwise in N. Hemisphere, anit-clockwise (counter clockwise) in S. hemisphere Upper-air pressure cells: Around low, air is rising, but we have an upper air high, so we have a reversal in direction (further & further from the low) As subsolar point migrates up, all the Hadley cells will move up & down, and all the high pressure cells where air is diverging from also move up and down Deep Currents Water in polar areas sink downward toward equator to get hot then come back up Good thermal energy Geography Textbook Notes 10/15/2013 8:19:00 AM Chapter 1 Steady-State Condition = Energy & material system that remains balanced over time, where conditions are constant Steady-State Equilibrium = When rates of inputs & outputs in system are equal & amounts of energy and matter in storage within system are constant Dynamic Equilibrium = Steady-State system demonstrating a changing trend over time Either increasing or decreasing systems may appear gradual Threshold = Moment where a system can no longer maintain its character, so it lurches into a new operational level, which may not be compatible with previous conditions Places system into metastable equilibrium Ex: Mountain adjusting after landslide Equilibrium is eventually achieved over time Human forced climate change is increasing the temp of ocean & atmosphere Higher temps cause higher evaporation rates affecting condensation levels Increased clouds affect daily temp range Night clouds – raise temps (acting as insulation) Day clouds – lower temps (acting as reflectors) Models of Systems Model = simplified, idealized representation of the real world Makes situation easier to understand Adjusting the variables produces different conditions & allows predictions of possible system operations Earth’s 4 Spheres Earth surface is 510 million km2 with 4 immense open systems Abiotic = nonliving Spheres include Atmosphere, hydrosphere & lithosphere Atmosphere Thin, gaseous veil surrounding earth, held in place by gravity Lower atmosphere is a combo of N, O2, Argon, CO2, Water Vapor and Trace Gases Hydrosphere Waters existing in atmosphere, on surface & crust near surface Cryosphere = frozen part of Hydrosphere Water exists in all 3 states: solid, liquid & gas Lithosphere Earth’s crust, & portion of upper mantle directly below crust Quite brittle Edaphosphere = soil layer & covers Earth’s land surfaces Biotic = living Sphere includes Biosphere Interconnected web, linking all organisms with their physical environment Exists in overlapping of abiotic spheres extending from sea floor, the upper layers of crustal rock, to 8 km into the atmosphere Life is sustainable within these natural limits Earth as a Geoid Geodesy = Science determining Earth’s shape & size by surveying & math Sir Isaac Newton thought that Earth was an oblate ellipsoid (has an equatorial bulge as a force pulling earth outward) Geoidal Epoch is modern era Earth measurement Geoid = The shape of the earth is Earth-shaped Balance among the gravitational attraction of Earth’s mass, distribution of water & ice along its surface & outward centrifugal pull cause by earth’s rotation Location & Time on Earth Geo science requires a grid to determine location of Earth Ptolemy (geographer, astronomer ..) contributed greatly to the principal used to create maps Latitude (parallels) Angular distance North or South of the equator, 0–90 Degrees Equator has latitude or 0 degrees, so to N its 90 Degrees & same for S Parallel = line connecting all points along the same latitudinal angle Latitude is name of angle (49 degrees N latitude) & parallel th means the line (49 parallel) Zones of natural environments: equatorial & tropical, subtropical, midlatitude, subartic or subantaric, artic or antartic Longitude (meridians) Angular distance East or West of a chosen point, 0 – 180 degrees Longitude is name of angle, where meridian names the line & both indicate distance east or west of an arbitrary prime meridian (meridian designated as 0 degrees) Galileo said longitude could be measured by time: 2 clocks The Earth rotates ¼ degree in 1 minute of time If you know what time it is in a place of known longitude, & you know what time it is where you are, you can know your longitude Requires very accurate clocks Any point on earth travels through 15 degrees of longitude every hour One clock indicates time at home port & other clock would be reset at local noon each day, as determined by the Sun position in the sky The time difference would indicate longitude & distance traveled: 1 hour for each 15 degrees of longitude John Harrison produced the marine chronometer (known as number 4) Calculating Longitude by time: EX Noon at 10 degrees E, 3:30 PM where you are 3 ½ house = 210 time minutes 210 time minutes *1/4 longitude degrees per time minute = 52.5 longitude degrees You are later than 10 degrees E, so east of it Your longitude is 52.5 degrees E & 10 degrees E = 62.5 degrees E OR Noon at 10 Degrees E Longitude, 3:30 PM with you 3 ½ h = 15 deg./hour *3.5 = 52.5 longitude degrees You are later than 10 degrees E, so east of it Your longitude is 52.5 degrees E & 10 degrees E = 62.3 degrees E Great circle = circle of Earth’s circumference whose center coincides with center of Earth Any plane dividing Earth into equal halves Small circle = have centers that do not coincide with Earth’s center Any plane dividing Earth into unequal halves Only one parallel is a
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