Earth-Sun Geometry and The Seasons - Chapter 3 PDF

**[Chapter 3: Earth-Sun Geometry and The Seasons]** **Big Bang Theory:** The theory that the universe originated about 14 billion years ago when all matter and energy erupted from a singular mass of extremely high density and temperature **Sun Angle:** The angle at which the Sun's rays strike the...

**[Chapter 3: Earth-Sun Geometry and The Seasons]** **Big Bang Theory:** The theory that the universe originated about 14 billion years ago when all matter and energy erupted from a singular mass of extremely high density and temperature **Sun Angle:** The angle at which the Sun's rays strike the Earth's surface at any given point and time. This angle is high at low latitudes and is progressively less at higher latitudes **Subsolar Point:** The point on Earth where the Sun angle is 90 degrees and solar radiation strikes the surface most directly at any given point in time **Plane of the ecliptic:** The flat plane on which the earth travels as it revolves around the sun **Perihelion:** The point of the Earth's orbit where the distance between the Earth and the Sun is least **Aphelion:** The point of the Earth's orbit where the distance between the Earth and the Sun is greatest **Axis:** The line around which the Earth rotates, extending through the poles **Circle of Illumination:** The great circle on Earth that is the border between night and day **International Date Line:** This line generally occurs at 180 degrees longitude, with some variations due to political boundaries, and marks the transition from one day to another on Earth **Spring Equinox:** Occurs on March 20 or 21 in the Northern Hemisphere when the subsolar point is located at the Equator **Summer Solstice:** Occurs on June 20 or 21 in the Northern Hemisphere when the subsolar point is located at the Tropic of Cancer **Tropic of Cancer:** The line of latitude at 23.5 degrees N where the subsolar point is located **Fall Equinox:** Occurs on September 22 or 23 in the Northern Hemisphere when the subsolar point is located at the Equator **Winter Solstice:** Occurs on December 21 or 22 in the Northern Hemisphere when the subsolar point is at the Tropic of Capricorn **Tropic of Capricorn:** The line of latitude at 23.5 degrees S where the subpolar point is located on the Winter Solstice **Solar Noon:** The time of day when the Sun angle reaches its highest point as the Sun arcs across the sky **Diurnal Cycle:** a 24-hour cycle **Celestial Dome:** A sphere that shows the Sun's arc, relative to the Earth, in the sky **[Chapter 4: The Global Energy System]** **Wavelength:** The distance between adjacent wave crests or wave troughs **Wave Amplitude:** The overall height of any given wave as measured from the wave trough to the wave crest **Electromagnetic Spectrum:** The radiant energy produced by the Sun that is measured in progressive wavelengths **Shortwave Radiation:** The portion of the electromagnetic spectrum that includes gamma rays, X-rays, ultraviolet radiation, visible light, and near-infrared radiation **Longwave Radiation:** The portion of the electromagnetic spectrum that includes thermal infrared radiation **Solar Constant:** The average amount of solar radiation received at the top of the atmosphere **Constant Gases:** Atmospheric gases such as nitrogen, oxygen, and argon that maintain relatively constant levels in space and time **Variable Gases:** Atmospheric gases such as carbon dioxide, water vapor, and ozone that vary in concentration in space and time **Greenhouse Effect:** The process through which the lower part of the atmosphere is warmed because longwave radiation from Earth is trapped by carbon dioxide and other greenhouse gases **Counter radiation:** Longwave radiation that is emitted toward the Earth's surface from the atmosphere **Ozone Layer:** The layer of the atmosphere that contains high concentration of ozone, which protect the Earth from ultraviolet radiation **Ozone Hole:** The decrease in stratosphere ozone observed on a seasonal basis over Antarctica, at to a lesser extent, over the Arctic **Insolation:** Amount of solar radiation measured in watts per square meter that strikes a surface perpendicular to the Sun's incoming rays **Radiation:** Energy that is transmitted in the form of rays or waves **Conduction:** The transfer of heat energy from one substance to another by direct physical contact **Direct Radiation:** Solar radiation that flows directly to the surface of the Earth and is absorbed **Absorption:** The assimilation and conversion of solar radiation in to another from of energy by a medium such as water vapor. In this process, the temperature of the absorbing medium is raised **Reflection:** The process through which solar radiation is returned directly to space without being absorbed by the earth **Albedo:** The reflectivity of features on the Earth's surface or in the atmosphere **Scattering:** The redirection and deflection of solar radiation by atmospheric gases or particles **Indirect Radiation:** Radiation that reaches Earth after it has been scattered or reflected **Sensible Heat:** Heat that can be felt and measured with a thermometer **Latent Heat:** Heat stored in molecular bonds that cannot be measured **Evaporation:** The process by which atoms and molecules of liquid gas gain sufficient energy to entre the gaseous plane **Angle of Incidence:** The angle at which the sun strikes Earth at any given place and time **Radiation Budget:** The overall balance between incoming and outgoing radiation on Earth **Net Radiation:** The difference between incoming and outgoing flows of radiation **[Chapter 5: Global Temperature Patterns]** **Troposphere:** The lowermost layer of the atmosphere, which lies between the Earth's surface and an altitude of about 12 km **Environmental Lapse Rate:** The decrease in temperature that generally occurs with respect to altitude in the troposphere (6.4 degrees / Kilometer) **Tropopause:** The top part of the troposphere, which is identified by when the air temperature is -57 **Stratosphere:** The layer of the atmosphere, between the troposphere and the mesosphere, that ranges between about 12km and 50km in altitude **Stratopause:** The upper boundary of the stratosphere where temperature reaches its highest points **Mesosphere:** A layer of decreasing temperature in the atmosphere that occurs from about 50 km to 80 km in altitude **Mesopause:** The upper boundary of the mesosphere where temperature reaches its lowest point **Thermosphere:** The upper layer of the atmosphere which occurs between about 80km and 480 km in altitude **Kinetic Energy:** The energy of motion in a body, measured as temperature, that is derived from movement of molecules within the body **Temporal Lag:** The difference in time between two events, such as when peak insolation and temperature occur **Maritime vs. Continental Effect:** The difference in annual and daily temperature that exists between coastal locations and those that are surround by large bodies of land **Maritime:** A place that is close to a large body of water that moderates temperature **Continental:** A place that is surrounded by a large body of land and that experiences a large annual range of temperature **Urban Heat Island:** The relatively warm temperatures associated with cities that occur because paved surfaces and urban structures absorb and release radiation differently than the surrounding countryside **[Chapter 6: Atmospheric Pressure, Wind, and Global Circulation]** **Air Pressure:** The force that air molecules exert on a surface due to their weight **High-pressure System:** A rotating column of air that descends toward the surface of Earth where it diverges **Low-pressure System:** A rotating column of air where air converges at the surface and subsequently lifts **Cyclones:** Low-pressure systems **Anticyclones:** High-pressure systems **Advection:** A horizontal transfer of air **Pressure Gradient Force:** The difference in barometric pressure that exists between adjacent zones of low and high pressure that results in airflow **Coriolis Force:** The force created by the Earth's rotation that causes winds to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere **Geostrophic Winds:** Airflow that moves parallel to isobars because of the combined effect of the pressure gradient force and Coriolis Force **Equatorial Trough:** Core of the low-pressure zone associated with the Intertropical Convergence Zone **Intertropical Convergence Zone (ITCZ):** Band of low pressure, calm winds, and clouds in tropical latitudes where air converges from the Southern and Northern Hemispheres **Trade Winds:** The primary wind system in the tropics that flows toward the Intertropical Convergence Zone on the equatorial side of the Subtropical High-Pressure System. These winds flow to the southwest in the Northern Hemisphere and to the northwest in the Southern Hemisphere **Tropical Easterlies:** Band of easterly winds that exists where northern and southern trade winds converge **Subtropical High (STH) Pressure System:** Band of high air pressure, calm winds, and clear skies that exists at about 25 to 30 degrees N and S latitude **Hadley Cell:** Large-scale convection loop in the tropical latitudes that connects the ITCZ and the STH **Polar Front:** The conduct in the midlatitudes between warm, tropical air and colder polar air **Westerlies:** Midlatitude winds that generally flow from west to east **Polar Front Jet Stream:** River of high-speed air in the upper atmosphere that flows along the polar front **Rossby Waves:** Undulations that develop in the polar front jet stream when significant temperature differences exist between tropical and polar air masses **Zonal Flow:** Jet stream patterns that is tightly confined to the high latitudes and is thus circular to semicircular in polar view **Meridional Flow:** Jet stream pattern that develops when strong Rossby waves exist and the polar front jet stream flows parallel to the meridians in many place **Polar High:** Zone of high atmospheric pressure at high latitudes **Polar Easterlies:** Band of easterly winds at high latitudes **Monsoon:** The seasonal change in wind direction that occurs in subtropical locations due to the migration of the ITCZ and STH **Sea Breeze:** Daytime circulatory system along coasts where winds flow from a zone of high pressure over water to a zone of relatively low pressure over land **Land Breeze:** Nighttime circulatory system along coasts where winds from a zone of high pressure over land flow to a zone of relatively low pressure over water **Valley Breeze:** Upslope airflow that develops when mountain slopes heat up due to re-radiation and conduction over the course of the day **Mountain Breeze:** Downslope airflow that develops when mountain slopes cool off at night and relatively low pressure exists in valleys **Katabatic Winds:** Downslope airflow that evolves when pools of cold air develop over ice caps and subsequently descend into valleys **Chinook Winds:** Downslope airflow that results when a zone of high air pressure exists on one side of a mountain range and a zone of low pressure exists on the other **Windward Side:** The side of a mountain range that faces oncoming winds **Leeward Side:** The side of a mountain range that faces away from prevailing winds **Gyres:** Large oceanic circulatory systems that form because currents are deflected by landscapes **Thermohaline Circulation:** The global oceanic circulatory system that is driven by differences in salinity **Downwelling Current:** A current that sinks to great depths within the ocean because water temperature drops and salinity increases **Upwelling Current:** A current that ascends to the surface of the ocean because water temperature warms and salinity decreases **[Chapter 7: Atmospheric Moisture and Precipitation]** **Capillary Action:** The process through which water is able to move upward against the force of gravity **Freezing:** The process through which water changes from the liquid to solid phase **Evaporation:** The process through which water changes from the liquid to vapor phase **Condensation:** The process through which water changes from the vapor to liquid phase **Sublimation:** The process through which water changes directly from ice to the vapor phase **Deposition:** The process by which water changes vapor changes directly to ice **Hydrosphere:** The water realm on Earth **Hydrologic Cycle:** A model that illustrates the way that water is stored and moves on Earth from one reservoir to another **Humidity:** A measure of how much water vapor is in the air. The ability of air to hold water vapor is dependent on temperature **Maximum Humidity:** The maximum amount of water vapor that a definable body of air can hold at a given temperature **Specific Humidity:** The measurable amount of water vapor that is in a definable body of air **Relative Humidity:** The ration between the specific and maximum humidity of a definable body of air **Dew-Point Temperature:** The temperature at which condensation occurs in a definable body of air **Transpiration:** The passage of water from leaf pores to the atmosphere **Evapotranspiration:** The combined processes of evaporation and transpiration **Adiabatic Processes:** Changes in temperature that occur due to variations in air pressure **Dry Adiabatic Lapse Rate (DAR):** The rate at which an unsaturated body of air cools while lifting or warms while descending. The rate is 10 degrees / 1000m **Level of Condensation:** The altitude at which water changes from the vapor to liquid phase **Wet Adiabatic Lapse Rate (WAR):** The rate at which a saturated body of air cools as it lifts. The average rate is 5 degrees/ 1000 m **Condensation Nuclei:** Microscopic Dust Particles Around which atmospheric water coalesces to form raindrops **Cirrus Clouds:** Thin, wispy clouds that develop high the troposphere **Cumulus Clouds:** Individual puffy clouds that develop due to convection **Stratus Clouds:** Layered sheets of clouds that have a thick and dark appearance **Radiation Fog:** Fog that develops at night when a temperature inversion exists **Temperature Inversion:** A layer of the atmosphere in which the air temperature increases, rather than cools, with altitude **Advection Fog:** Fog that develops when warm air flows over cooler air **Sea Fog:** Fog that develops when cool, marine air comes into direct contact with colder ocean air **Convection Uplift:** Uplift of air that occurs when bubbles of warm air rise within an unstable body of air **Orographic Uplift:** Uplift that occurs when a flowing body of air encounters a mountain range **Frontal Uplift:** Uplift of air that occurs along the boundary of contrasting bodies of air **Convergent Uplift:** Uplift of air that occurs when large bodies of air meet in a central location **Rain Shadow:** The body of land on the leeward side of a mountain range that is relatively dry and hot due to adiabatic warming and drying **Stable Air:** A body of air that has a relatively low environmental lapse rate compared to potential uplifting air; thus, strong convection cannot occur **Unstable Air:** A body of air that has a relatively high environmental lapse rate compared to uplifting air within it; thus, strong convection can occur **[Chapter 8: Air Masses and Cyclonic Weather Systems]** **Air Mass:** A large body of air in the lower atmosphere that has distinct temperature and humidity characteristics **Stationary Front:** A boundary where contrasting air masses are flowing parallel to one another **Warm Front:** A frontal boundary where warm air is advancing into relatively cool air. This front is typically associated with slow, steady precipitation **Cold Front:** A frontal boundary where cold air is advancing into relatively warm air. This front is typically associated with intense rain in short duration **Thunderstorms:** A brief, but intense storm that contains strong winds, lightning, thunder, and perhaps hail **Midlatitude Cyclone:** A well-organized low-pressure system in the midlatitudes that contains warm and cold fronts **Cyclogenesis:** The sequence of atmospheric events along the polar jet stream that produces midlatitude cyclones **High-pressure Ridge:** An elongated area of elevated air pressure in the upper atmosphere that is typically associated with sunny skies and calm winds **Low-pressure Trough:** An elongated area of depressed air pressure, in the upper atmosphere that is typically associated with cloudy skies and rain **Occluded Front:** The area where a cold front begins to overtake a warm front and thus life warm surface air aloft **Downdraft:** A rapidly moving current of cool air that flows downward in a thunderstorm **Updrafts:** An area of rapidly flowing air that is moving upward within a thunderstorm **Supercell Thunderstorms:** Large thunderstorms that contain winds moving in opposing directions and are associated with strong winds, lightning, thunder, and sometimes hail and tornadoes **Mesocyclones:** Strong updrafts that rotate within a supercell thunderstorm **Hook Echo:** The diagnostic feature of Doppler radar indicating strong rotation is occurring within a thunderstorm and tornado development is thus possible **Easterly Wave:** A slow-moving trough of low pressure that develops within the tropical latitudes **Tropical Depression:** A tropical low-pressure system with central sustained winds ranging between 20 knots and 34 knots **Tropical Storm:** A tropical low-pressure system with maximum sustained winds between 35 knots and 63 knots **Hurricane:** A tropical circulatory system with maximum sustained winds greater than 63 knots **[Chapter 9: Global Climates and Global Climate Change]** **Weather:** Day-to-day changes that occur with respect to temperature and precipitation **Climate:** Average precipitation and temperature characteristics for a region that are based on long-term records **Potential Evapotranspiration (Potential ET):** A measure of the maximum possible water loss from a given land area assuming sufficient water is available **Actual Evapotranspiration (Actual ET):** The quantity of water actually removed from a given land areas by evaporation and transpiration **Proxy Date:** Indirect evidence of an event. For examples, fossil pollen is a proxy indicator of climate change because vegetation reflects climate **Dendrochronology:** The dating of past events and variations in the environment and climate by studying the annual growth rates of trees **Oxygen Isotope Stages:** Periods of time that have distinct O-18/O-16 ratios, which are used to reconstruct prehistoric climate change **Milankovitch Theory:** The theory that best explains Pleistocene glacial/interglacial cycles through long-term variations in Earth's orbital eccentricity, tilt, and axial precession **Anthropogenic:** Environmental changes caused by humans **Fossil Fuels:** Carbon-based energy sources, such as gasoline and coal, that are derived from ancient organisms **[Chapter 20: Relevance of Physical Geography to Environmental Changes]** **Carrying Capacity:** The maximum number of organisms that can live in a given area of habitat without degrading it and causing social stressed that result in population decline **Water Rights:** Legally protected rights to take possession of water occurring in a natural waterway and to divert that water for beneficial purposes **Arable Land:** Land that has the high potential to be cultivated for crop production **Soil Salinization:** The process in which soils become enriched in soluble salts such as sulfates from calcium and potassium **Land Cover:** The various things that cover the landscape, such as forests, roads, and water bodies, at any point in time