Physical Geography Final Exam
auroras
A spectacular glowing light display in the ionosphere, stimulated by the interaction of the solar wind with principally oxygen and nitrogen gases at high latitudes; called aurora borealis in the Northern hemisphere and aurora australis in the Southern Hemisphere. Interaction between solar wind and magnetosphere produce Auroras • Aurora Borealis (Northern Lights), Aurora Australis (Southern Lights) • Most often and clear seen at high latitudes-due to deflection of solar wind poleward
Closed Systems
A system that is shut off from the surrounding environment so that it is self-contained. Closed systems are rarely found in nature. Ex: Nature is essentially a closed system in terms of physical matter and resources---air, water, and material resources.
Atmosphere
A thin, gaseous veil surrounding Earth, held to the planet by the force of gravity. Formed by gases arising from within Earth's crust and interior and the exhalations of all life over time, lower temperature is unique. Lower atmosphere: Combination of both nitrogen, oxygen, argon, carbon dioxide, water vapor, and trace gases.
electromagnetic spectrum
All the radiant energy produced by the Sun placed in an ordered range; divided according to wavelengths. • Any object above absolute zero (-273 K) emits EM radiation • EM energy grouped based on wavelength • Portion of EM spectrum of greatest interest to humans: shortwave, visible and infrared • Radiant energy emitted by Sun consists of: • 7% gamma, X-ray and UV • 47% visible • 46% infrared
cloud-albedo forcing
An increase in albedo (the reflectivity of a surface) caused by clouds due to their reflection of incoming insolation. • cloud albedo forcing - reflect insolation (increase albedo) cools surface
cloud-greenhouse forcing
An increase in greenhouse warming caused by clouds because they can act like insulation, trapping longwave (infrared) radiation.• cloud greenhouse forcing - trap longwave (insulation) heat surface • industrial pollution/volcanic activity - increase atmospheric albedo
Latitude
Angular distance North or south of the equator, measured from the center of the Earth. Runs East and West. Equator: 0 degrees latitude North Pole: 90 degrees North South Pole: 90 degrees South Equatorial Circumference: 40,075 km or 24,902 miles Polar Circumference: 40,008 km or 24,860 mi.
Longitude: ---Meridian ---Prime Meridian ---International Date Line
Angular distance east or west of a point on Earth's surface, measured from the center of Earth. Runs North and South.
Systems Theory
Any set of ordered, interrelated components and their attributes, linked by flows of energy and matter, as distinct from the surrounding environment outside the system. Ex: Within Earth's systems, both energy and matter are stored and retrieved, (matter is mass that assumes physical shape and occupies space; energy is a capacity to change the motion of, or to do work on, matter.)
Latitudinal Geographic Zones
Arctic: 66.5 degrees N to North Pole Subarctic: 55 degrees N to 66.5 N Midlatitude: 35 N to 55 N Subtropical: 23.5 N to 35 N Equatorial and Tropical: 23.5 N to 23.5 S Subtropical: 23.5 S to 23.5 S Midlatitude: 35 S to 55 S Subantarctic 55 S to 66.5 S Antarctic 66.5 S to SouthPole Used for reference and comparison, but are not rigid.
System Feedbacks
As a system operates, it generates outputs that influence its own operations. These outputs function or "information" that returns to various points in the system via pathways called feedback loops.
Absorption
Assimilation and conversion of radiation from one form to another in a medium. In the process, the temperature of the absorbing surface is raised, thereby affecting the rate and wavelength of radiation from that surface. • Assimilation of radiation by matter; converts energy from one form to another • 69% of insolation is absorbed (31% reflected due to albedo) - Converted into infrared radiation or chemical energy • 45% incoming insolation absorbed by land/water • 24% incoming insolation absorbed by atmosphere (gases, dust, clouds, stratospheric O3)
Vernal, autumnal equinox
At this time circle illumination passes through both poles, so that all locations on Earth experience a 12-hour day and 12-hour night. Fall Equinox: Sept 22nd Spring Equinox: March 21st
solar constant
Average amount of energy reaching the top of Earth's atmosphere • = 1372 W/m2 (1W = 1J/sec) The amount of insolation intercepted by Earth on a surface perpendicular to the Sun's rays when Earth is at its average distance form the Sun; a value of 1372 W/m^2 (1.968 calories/cm^2) per minute; averaged over the entire globe at the thermopause.
Solar wind
Clouds of ionized (charged) gases emitted by the Sun and traveling in all directions from the Sun's surface. Effects on Earth include auroras, disturbance of radio signals, and possible influences on weather. • Composed principally of hydrogen nuclei and free electrons • Travels slower than light • Takes 3 days to reach Earth • Solar wind interacts with the Earth's Magnetosphere
Geographic Information Systems
Computer-based data-processing tool for gathering, manipulating, and analyzing geographic data. --Combines spatial and attribute data. --Maps can contain multiple layers: >Physical Features >Cultural Features
4 Major map Classes:
Cylindrical: Mercator Projection Planar: Gnomonic Projection Conic: Oval:
Scattering
Deflection and redirection of insolation by atmospheric gases, dust, ice, and water vapor; the shorter the wavelength, the greater the scattering; thus, skies in the lower atmosphere are blue. • Change light's direction without altering the wavelength • Accounts for ~ 7% of Earth's albedo • Rayleigh scattering - s-wave radiation > scatter; l-wave < scatter • Sun's angle - oblique vs. direct angle • Diffuse radiation - downward component of scattered light; caused by clouds and atmosphere
True Shape
Direction maintained BUT area sacrificed because scale varies; used navigational purposes.
5 Key parameters needed to represented on a map
Direction, Distance, area, shape, proximity. Transferring the geographic grid to spherical form to flat surface requires using projections which leads to distortion.
Particulates
Dust, dirt, soot, salt, sulfate aerosols, fugitive natural particles, or other materials particles suspended in air.
axial tilt
Earth's axis tilts 23.5 degrees from a perpendicular to the plane of the ecliptic (plane of Earth's orbit around the Sun). • Plane of the Elliptic - flat plane that intersects the Sun and Earth • Earth's axis is tilted 23.5o relative to this plane • Axial tilt remains constant - North Pole always points to the North Star (Polaris) • Key to Seasonality - without tilt no seasonal changes would occur • Constant Spring/Fall conditions with equal day and night length for every point on Earth
Lithosphere
Earth's crust and a portion of the upper mantle directly below the crust from the Lithosphere.
magnetosphere
Earth's magnetic force field, which is generated by dynamo-like motions within the planet's outer core; deflects the solar wind flow toward the upper atmosphere above each pole. ---magnetic field surrounding the Earth resulting from internal processes within the Earth's metallic core • Magnetosphere deflects the solar wind towards poles leaving little to enter atmosphere • Shields Earth's inner atmosphere and surface from harmful ionizing radiation • Pressure of solar wind pushes the magnetosphere against the Earth windward and stretches it out leeward
Hydrosphere
Earth's waters exist in the atmosphere, on the surface, and in the crust near the surface. Collectively, these waters form the hydrosphere.
The Greenhouse Effect and Atmospheric Warming
Earth: cool body radiator • Atmosphere absorbs heat energy (CO2, H20, CH4, NOx, etc.) • A real greenhouse traps heat inside - e.g. car in parking lot • Atmosphere delays transfer of heat from Earth into space 1. The process whereby, radiatively, active gases (carbon dioxide, water vapor, methane, and CFCs) absorb and emit energy at longer wavelengths, which are retained longer, delaying the loss of infrared to space. Thus, the lower troposphere is warmed through the radiation and re-radiation of infrared wavelengths. The approximate similarity between this process and that of a greenhouse explains the name. 2.
Map
Generalized view of an area, usually some portion of Earth's surface, as seen from above and greatly reduced in size. Usually represents a specific characteristic of a place or area. Ex: Rainfall
Sensible Heat
Heat that can be measured with a thermometer; a measure of the concentration of kinetic energy from a molecular motion.
Atmospheric Composition Criterion
Heterosphere: Outer atmosphere --80 km (50 ml) outwards --layers of gasses sorted by gravity --not evenly mixed Homosphere: --Surface to 80 km (50 ml) --Gasses evenly blended -- Variations in H20 (v), pollutants, trace chemicals in lower position.
Cryosphere
Ice sheets, ice caps, and fields, glaciers, ice shelves, sea ice, and subsurface ground ice.
Positive Feedbacks
If feedback information encourages change in the system, it is positive feedback. Unchecked positive feedback in a system can create a runaway condition. In natural systems, such unchecked system changes can reach a critical limit, leading to instability, disruption, or death of organisms. Ex: Global climate change as summer sea ice melts in the Arctic. A arctic temps. rise summer sea ice and glacial melting accelerate. This causes light-colored snow and sea surfaces, which reflect sunlight and so remain cooler, to be replaced by darker-colored open surfaces, which absorbs sunlight and become warmer. Result: ocean absorbs more solar energy, which raises the temperature, which in turn, melts more ice and so forth. This is a positive feedback loop.
Negative Feedbacks
If the feedback information discourages change in the system, it is negative feedback. Common in nature. Ex: In a forest healthy trees produce roots that stabilize hillslopes and inhibit erosion, producing a negative feedback. If the forest is damaged or removed, perhaps by fire or logging practices, the hillslope may become unstable and subject to landslides or mudslides. This instability affects nearby systems as sediment is deposited into streams, along coastlines, or into developed areas.
Active Remote Sensing
Instruments that direct a beam of energy at a surface and analyze the energy reflected back and active remote sensors.
insolation
Intercepted solar radiation arriving at the top of Earth's atmosphere and reaching Earth's surface. Solar radiation that is incoming to Earth systems.
Mercator Projection
Invented by Gerardus Mercator in 1509. --Is a cylindrical projection Conformal projection, with Meridians appearing as equally spaced straight lines and parallels appearing as straight lines that are spaced closer together near the Equator.
Meridian
Line connecting all points along the same longitude is a meridian.
sunspots
Magnetic disturbances on the surface of the Sun, occurring in an average 11-year cycle; related flares, prominences, and outbreaks produce surges in solar wind. relatively cool areas of the sun caused by magnetic storms on the surface of the sun (up to 10x size of Earth) • ~11 year sunspot cycle - last minimum in 2007; next maximum summer 2013 • Weather effects: 1740-1998 sunspot cycle corresponds to wet/dry cycling in western US • Flares, Prominences and Coronal Mass Ejections that create Solar Wind are associated with the magnetic storms that produce sunspots • Can also affect telecommunications, satellites and power grids
Remote sensing
Measurement of some property of an object by means other than direct contact. I.E. gathering information from great distances and over broad areas using instruments usually mounted on air craft or orbiting space platforms Can be used to perceive/analyze physical, chemical, biological, and cultural aspects of the environment.
Prime Meridian
Meridian designated as 0 degrees. Earth's prime meridian pass through the Royal Observatory in Greenwich, England, as set by an 1884 treaty.
Winter, Summer solstice
Occurs when the sub-solar point is furthest form the Equator (23.5 degrees N/S) Summer Solstice: June 21st Winter Solstice: Dec. 21st
Plane of the Elliptic
Plane along which the Earth travels during its orbit • Earth's axis tilted 23.5o relative to the plane of the elliptic
Anthropogenic Pollution
Pollution that is Caused or produced by humans
Air Pressure
Pressure produced by the motion, size, and number of gas molecules in the air and exerted on surfaces in contact with the air; an average force at sea level of 1kg/cm^3 (14.7 lb/in^2). Normal sea-level pressure, as measured by the height of a column of mercury (Hg), is expressed as 1013.2 millibars, 760 mm of Hg, or 29.92 inches of Hg. Air pressure can be measured with mercury or aneroid barometers. atmosphere - exerts large downward pressure • results from presence of air molecules (motion, size, number) • felt by any surface in contact by air • gravity - compresses air near surface (increase density) • ½ mass of atmosphere below 5500 m • sea level pressure = 1kg/m2; 1013.2 mb; 101.32 kPa
Scale
Ratio of map units to ground units. • ratio of the distance on a map to that in the real world • e.g. 1:1 means 1 unit on the map is equal to 1 unit in the real world • the larger the fraction (i.e. the smaller the denominator) the larger the scale • e.g. 1:24.000 is a larger scale than 1:250,000 • large scale - more detail (less area) vs. small scale (less detail, greater area)
Passive Remote Sensing
Record wavelengths of energy radiated from a surface; ex: infrared. Detects energy naturally emitted by the object or that is reflected by sunlight.
Map Projection
Reduction of the spherical Earth to a flat surface. Globes: Model of the surface of the Earth using the network of parallels and meridians. ---Problems: two small, not detailed enough, not portable.
Cartography
Science and art of mapmaking, often blending aspects of geography, engineering, math, computer science, and art.
Insolation
Solar radiation that is incoming to Earth systems. • insolation drives the Earth-atmosphere system (direct and diffuse) Figure 4.4 • decreased insolation receipt poleward of 25o • Equatorial/Tropical region - high sun angle and consistent daylength (180 - 220 W/m2) • Sub-tropical region (low-latitude deserts) - no clouds (240 - 280 W/m2)
Open System
Systems in nature generally are not self-contained; Inputs of energy and matter flow into the system, and outputs of energy and matter flow into the system. Ex: Earth is an open system in terms of energy because Solar energy enters freely and heat energy leaves, going back into space.
Energy Balance in the Troposphere
The Greenhouse Effect and Atmospheric Warming • Clouds and Earth's "Greenhouse" • Earth-Atmosphere Radiation Balance long term: inputs = outputs
Refraction
The bending effect on electromagnetic waves that occurs when insolation enters the atmosphere or another medium; the same process disperses the component colors of the light passing through a crystal or prism. • bending of light (EM radiation) - occurs when light moves from one medium to another • e.g. prism and rainbows • sunrise/sunset - 4 minutes early/late due to refraction
Kinetic Energy
The energy of motion in a body; derived from the vibration of the body's movement own movement and stated as temperature. in use • motion (flowing water) • vibration (water molecules)
Heat
The flow of kinetic energy from one body to another because of a temperature difference between them.
Troposphere
The home of the biosphere ; the lowest layer of the homosphere, containing approximately 90% of the total mass of the atmosphere; extends up to the tropopause; occurring at an altitude of 18 km (11 mi) at the equator, at 13 km (8 mi) in the middle latitudes, and at lower altitudes near the poles. --Surface to 18 km (11mi) --Height varies with latitude --Tropopause--acts as cap --90% mass of atmosphere --Home of the Biosphere: life processes, weather --Normal lapse rate: average cooling at rate of 6.4C/km (3.5F/1000 FT) --Environmental lapse rate--actual loose lapse rate
Biosphere
The intricate, interconnected web that links all organisms with the physical environment is the biosphere. Area in which physical and chemical factors form the context of life. Exists in the overlapping of the 3 abiotic, or nonliving spheres, extending from the sea floor, the upper layers of the crustal rock to about 8 km into the atmosphere
Net Radiation
The net all-wave radiation available at Earth's surface; the final outcome of the radiation balance process between incoming shortwave insolation and ougoing longwave energy.
sub-solar point
The only point receiving perpendicular insolation at a given moment---that is, the Sun is directly overhead. Sub-Solar Point - point on Earth's surface where the Sun's rays are perpendicular to the surface (90o) • Angle of Sun's rays hitting Earth surface varies with latitude and time of year • Direct angle = more concentrated energy • Oblique angle = more diffuse energy • Receipt of insolation at the thermopause is 2.5x greater annually over equator than poles
Transmission
The passage of shortwave and long-wave energy through space, the atmosphere, or water. Passage of shortwave or longwave radiation through atmosphere or water • Atmospheric energy budget comprised of shortwave inputs and longwave outputs • Shortwave and longwave radiation interact with gases and dust: scattering and refraction
Perihelion
The point of Earth's closest approach to the Sun in its elliptical orbit, reached on January 3 at a distance of 147,255,000 km. (91,500,000 mi); variable over a 100,000 year cycle.
Aphelion
The point of Earth's greatest distance from the Sun in its elliptical orbit; reached on July 4 at a distance of 152,083,000 km. (94.5 million mi); variable over 100,000-year cycle.
Stratosphere
The portion of the homosphere that ranges from 20 to 50 km (12.5 to 30 mi) above Earth's surface, with temperatures ranging from -57 degrees C (-70 F) at the tropopause to 0 degrees C (32 F) at the stratopause. The functional ozonosphere is within the stratosphere. --18 to 50 km
Mesosphere
The upper region of the homosphere from 50 to 80 km (30 to 50 mi) above the ground; designated by temperature criteria; atmosphere extremely rarified. --Noctilucent clouds:
Equal Area
Used whenever area is important. BUT these maps distort shape through shearing and stretching. Coin placed on anywhere on the map represents the same amount of area.
Ozone
a colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light. It differs from normal oxygen (O2) in having three atoms in its molecule (O3).
Normal Lapse Rate
average cooling at rate of 6.4C/km (3.5F/1000 FT)
Clouds, Aerosols, and the Atmosphere's Albedo
cloud-albedo forcing cloud-greenhouse forcing
thermopause
outer boundary of Earth's atmosphere A zone approximately 480 km (300 mi) in altitude that serves conceptually as the top of the atmosphere; an altitude used for the determination of the solar constant. Provides point at which to assess the arriving solar radiation before it is diminished by scattering and absorption as it passes through the atmosphere.
The Urban Environment
urban heat island dust dome
Simplified Surface Energy Balance
• +SW (insolation) • -SW (reflection) • +LW (infrared) • -LW (infrared)
Energy Balance at Earth's Surface
• Daily Radiation Patterns • Simplified Surface Energy Balance • The Urban Environment Daily/Seasonal Radiation Patterns
Energy Pathways and Essentials
• Land, oceans, clouds, atmospheric gases and dust intercept solar Energy - imbalance exists in energy receipt and distribution • Energy Pathways and Principles - Shortwave energy in from the Sun - Longwave energy out from Earth surface - Atmosphere/surface heated by solar energy: unevenly distributed by latitude and season -Transmission -Scattering -Refraction
Clouds and Earth's "Greenhouse"
• cloud effect f(x) of: type, thickness, and height • high cirrus vs. low stratus clouds • shortwave flux: high over tropics (dense, low clouds) and sub-tropical deserts (lightly colored) • longwave flux: high over sub-tropics (deserts: little cloud cover); low in equatorial regions (thick cloud cover)
Photochemical Smog Pollution
- Air pollution produced by the interaction of ultraviolet light, nitrogen dioxide, and hydrocarbons; produces ozone and PAN through a series of complex photochemical reactions. Automobiles are the major source of the contributive gases.
Industrial Smog and Sulfur Oxides
1. Air pollution associated with coal-burning industries; it may contain sulfur oxides, particulates, carbon dioxide, and exotics. 2.
Earth's Four/Five "Spheres"
1. Atmosphere 2. Lithosphere 3. Hydrosphere 4. Biosphere 5. Cryopshere
Conduction, Convection, and Advection
1. Slow molecule-to-molecule transfer of heat through a medium, from warmer to cooler portions. - Molecule to molecule transfer - Heat flow: warm to cold - e.g. leather seats in a car 2. Transfer of heat from one place to another through the physical movement of air; involves a strong vertical motion. - Energy transferred by vertical movement - physical mixing - e.g. convection 3. Horizontal movement of air or water from one place to another. - Horizontally dominant movement
Albedo and Reflection
1. The reflective quality of a surface, expressed as the percentage of reflected insolation to incoming insolation; a function of surface color, angle of incidence, and surface texture. albedo - reflective quality of a surface • expressed as % of insolation reflected • e.g. water - oblique vs. direct angle; calm vs. stormy 2. The portion of arriving insolation that is returned directly to space without being absorbed and converted into heat and without performing any work. • reflection - insolation that is bounced back to space without being absorbed Equator/tropics: 19-38% (cloud cover) • polar regions: ~ 80% • Earth's average albedo = 31% • clouds = 21% • ground = 3% • atmosphere = 7% (reflection/scattering) • high latitude - high albedo (January) • tropic of Capricorn - high albedo (July) cloud cover
Chlorofluorocarbon Compounds (CFCs)
1.any of a class of compounds of carbon, hydrogen, chlorine, and fluorine, typically gases used in refrigerants and aerosol propellants. They are harmful to the ozone layer in the earth's atmosphere owing to the release of chlorine atoms upon exposure to ultraviolet radiation.
International Date Line
180 degrees E/W of prime meridian on opposite side of the planet. Marks place where each day officially begins at 12:01 A.M. From this line the New day sweeps Westward. Westward movement of time is created by Earth's turning eastward on its axis.
Ionosphere
A layer in the atmosphere above 80 km (50 mi) where gamma rays, X-rays, and some ultraviolent radiation are absorbed and converted into longer wavelengths and where the solar wind stimulates the auroras. --Absorbs cosmic rays, gamma rays, X-rays, some UV rays --Spans mesosphere and thermosphere.
Ozonosphere
A layer of ozone occupying the full extent of the stratosphere (20 to 50 km, or 12 to 30 mi, above the surface); the region of the atmosphere where ultraviolet wavelengths of insolation are extensively absorbed and converted into heat. --Part of stratosphere --Ozone (O3) absorbs UV energy and converts it to heat energy.
wavelength
A measurement of a wave; the distance between the crests of successive waves. The number of waves passing a fixed point in 1 second is called frequency of the wavelength. ---Wavelength: Distance between the crest and trough. ---Amplitude: wave height The shorter and the wavelength the more intense the energy. The hotter the object the shorter the wavelength. Number of waves passing a fixed point in 1 second is the frequency.
Thermosphere
A region of the heterosphere extending from 80 to 480 km (50 to 300 mi) in altitude; contains the functional ionosphere layer. -- roughly same as heteropshere -- 80 km (50 mi) outwards
Temperature Inversion
A reversal of the normal decrease of temperature with increasing altitude; can occur anywhere from ground level up to several thousand meters; functions to block atmospheric convection and thereby trap pollutants.