Physical Geography
international dateline
follows 180th meridian, except through Aleutian Islands, alaska, and the island nation of kiribati
Polar Projection
map projection centered on Earth's North or South Pole; scale increases outward, shows only one hemisphere, true shapes of small areas
scientific method
the formal process that a scientist uses to solve a problem, which involves first observing a formulating a hypothesis then testing and evaluating the results
relief
the high point of a location compared to its lowest point at a specific location. Mt Everest is highest, mariana trench is the lowest
scattering
the process by which particles and molecules deflect incoming solar radiation in different directions
What is physical geography?
the study of the earth's living and nonliving systems, the study of landscapes and natural processes
Goode Projection
Equal-area map projection often used to display information such as climate or soil type, shows true sizes of regions on Earth's surface
Variable Gases
Carbon dioxide needed by green plants, absorbs long-wave radiation (.039%); Water vapor varies up to 2%, absorbs heat; Ozone layer in the stratosphere
Map
2-dimensional representation of the Earth's surface; show size, shape, distance, and direction; They are imperfect since Earth is a sphere
December Solstice
December 21 or 22 when the subsolar point is at 23 1/2 degrees S (Tropic of Capricorn); S Pole has 24 hour of daylight; daylength increases from equator to S Pole; Northern hemisphere tilted away from the sun
Electromagnetic Spectrum
Defines the entire range of wavelengths for all energy
Thermosphere
Hottest layer
Summer Solstice
June 21 or 22 when the subsolar point is at 23 1/2 degress N (Tropic of Cancer); Circle of illumination grazes Arctic and Antarctic circles; N Pole has 24 hours of daylight; Northern hemisphere tilted toward the sun; daylength increases from equator to N Pole
Insolation
The flow rate of incoming solar energy, as measured at the top of the atmosphere (incoming solar radiation)
Solar Energy
Every second, the Sun provides us with energy to meet the world's energy demands for 10 days
cartography
a sub field of geography, representing earth through maps
hydrosphere
all the water in the world, in all its form
What is geography
an ancient discipline devoted to the study of the earth, geographers take into account both spacial consideration and temporal consideration, which is related to changes with the passage of time
latitude
an angular distance for a point north or south of the equator, as measured from the earth's center, like ladders - 7 important latitudes - tropic of cancer - equator - poles - Capricorn - arctic circle - antarctic circle - latitude zones - low, mid, high - equatorial, tropic, subtropical
longitude
angular distance for a point east or west of the prime meridian
3 measures of time
- tropical year = amount of time to rotate around sun - lunar month - solar day
steps of scientific method
1. generate critical inquiry from investigations and field observations 2. formalize questions into a testable hypothesis to explain observations 3. select method of analysis and control for variables and conditions for the experiment 4. collect data for controlled experiment 5. conduct experiments to test hypothesis 6. reject or accept hypothesis 7. document results, provide new science facts, and apply them to support theory or greater understanding
5 themes of geography
1. location 2. place 3. region 4. human earth relationships 5. movement
4 human impacts on the global energy balance
1. rising concentration of greenhouse gases 2. changes in surface albedo 3. air pollution 4. thinning of ozone layer in the stratosphere
Geographic Information Systems (GIS)
A combination of software, data, and operational organization that provides the capacity to capture and communicate spatial relationships among geographic features, values, and objects in digital databases
Map Projections
A system of parallels and meridians represents the Earth's curved surface drawn on a flat surface. Curved surface cannot be projected onto a flat sheet without distortion. (Cylindrical, Conic, Plane, Elliptical)
Electromagnetic Radiation
A wave form of energy radiated by any substance possessing internal energy; it travels through space at the speed of light; does not require a medium
Heterosphere
Above 100 km, gas molecules are sorted into layers by molecular weight and electric charge
Global Positioning Systems (GPS)
Accurately determines geographic location, consists of 24+ satellites that orbit Earth, receivers work by measuring and triangulating time delay of signals from a minimum of three (usually four or more) GPS satellites
Distortions in Map Projections
All maps are distorted; conformity (true shape map preserves shape but distorts size, Mercator), Equivalence (Equal-area projection, preserves size but distorts shape, Goode), Compromises (sacrifice equivalency and conformity for the sake of portraying a general balance between the two (Winkel Tripel)
Radiation
All objects radiate electromagnetic energy, but hot objects radiate greater intensity than cool objects
Reflection vs. Absorption
An object that is a good absorber of insolation warms up rapidly (its atoms vibrate more rapidly and more easily than an object that is a good reflector)
AM and PM
Ante-Meridian Post-Meridian
Annual Insolation by Latitude
Average insolation over a 24 hour day depends on: Angle at which Sun's rays strike Earth (controlled by latitude, time of year, time of day); How long the place is exposed to Sun's rays (controlled by latitude and time of year); Annual insolation decreases from equator to poles
Seasonal Change
Axis aims toward Polaris (North Star), Axis tilted at an angle of 23 1/2 from a right angle to plane of the ecliptic, Earth has seasons because of the tilt of the axis
Homosphere
Below 100 km, Gases are uniformly mixed by turbulence
Globe
Best representation of Earth, maintain correct geographic relationships between points, and can accurately represent spatial relationships between points on Earth
Elliptical Projection
Central meridian and all parallels are straight lines, with relative sizes represented accurately, but shapes are distorted at the edges; often used for thematic or political maps
Equinox
Circle of illumination passes through both poles; subsolar point at equator; day and night of equal length everywhere on the globe; Vernal (March 21), Autumnal (September 23)
Mesosphere
Coldest near top of this layer
Conic Projection
Cone sits atop the globe like a cap, with the point of the cone typically situated over one of the poles, accuracy is greatest along the circle it touches, good format for mapping mid-latitude regions
Mercator Projection
Conformal map projection with horizontal parallels and vertical meridians, used for navigation, scale increases from equator to poles, the further away the more distorted
Longwave Radiation
Electromagnetic energy that includes a portion of infrared radiation, as well as microwaves, radar, and wavelengths conventionally associated with communication transmissions, such as radio and television
Shortwave Radiation
Electromagnetic energy that includes ultraviolet light, the visible light spectrum, and near-and shortwave-infrared radiation
Daily insolation
Energy received from the sun varies each day and over a year, and it varies by latitude; Depends on angle of sunlight and day length
Arctic/Subarctic Latitude Zone
Enormous variation in annual insolation, extreme variation in day length (Winnepeg); covered by tundra or evergreen forests
Large Scale vs. Small Scale
Entire country is small scale while one city is a large scale
Polar Latitude Zone
Greatest seasonal insolation contrasts, 6-month day, 6- month night (Fairbanks)
Tropical Latitude Zone
High annual insolation, home of world's greatest deserts
The Earth's Energy Output
Incoming shortwave energy from the sun (absorbed, scattered, reflected); Outgoing longwave energy from the Earth (absorbed, scattered, reflected)
Equatorial Latitude Zone
Intense insolation giving rise to lush plant life and great biodiversity, day and night roughly equal (Borneo)
Geobrowsers and 3-D mapping
Internet mapping, used for reporting on humanitarian issues and tracking eco-disasters; computer programs that access and query geographic data draped over a computer-generated globe (Google Earth)
Subtropical Latitude Zone
Large annual insolation; dry. hot summers, mild wet winters, short transition seasons (San Antonio)
Declination
Latitude of the subsolar point
Variations in Heating by Latitude and Season
Latitudinal differences: Annual insolation decreases from equator to poles; Seasonal changes in day length vary by latitude; Solar insolation is strongest near the equator and weakest near the poles
Stratosphere
Layer above the troposphere, where temperature slowly increases with height
Isolines
Line connecting points of equal value on a map; Isobar (line of constant pressure), Isotherm (line of constant temperature), Isohyet (line of constant rain), Isoamplitude (line of constant wave amplitude)
Troposphere
Lowest layer of the atmosphere, where human activity and most weather takes place; temperature usually decreases with height
Permanent Gases
Nitrogen (78%), Oxygen (21%), Argon (.93%)
Subsolar Point
Noon, Sun directly overhead at this one point
Exosphere
Outermost layer
Perihelion
Point in orbit when Earth is closest to Sun (Jan.3)
Aphelion
Point in orbit when Earth is farthest from Sun (July)
Plane Projection
Produced by projecting a map from a center lit globe onto a piece of paper touching the globe at any point; can choose any center point, from which directions and distances are true, but in outer areas, shapes and sizes are distorted
Global Dimming
Reduction in industrial pollution has led to increase in solar insolation, decrease in atmospheric particles lowers the reflectance of the sun's incoming energy, temperatures may increase adding to existing warming trend
Plane of the Ecliptic
Seasonal changes occur because the Earth's axis is tilted compared to the plane of the Earth's orbit around the Sun
Circle of Illumination
Separates day and night; Equator always experiences 12 hours of day length; Poles experience either 24 hours or 0 hours; Other latitudes have varying day length each day
Topographic Maps
Show elevation contours, lines closer together represent steeper terrain, often used in geography
Solar Radiation from the Sun
Solar energy is generated by nuclear fusion; solar energy travels as SHORTWAVE radiation; the Earth receives one-half of one-billionth of the Sun's total energy output
Midlatitude Zone
Strong seasonal contrasts in insolation and length of day (Chicago, Tuscany)
Tropopause
The boundary where the troposphere ends
Map Scale
The relationship between distance on a map and distance on the ground, given as a fraction or a ratio; Verbal scale (1 cm = 1 km), Representative fraction (1 cm on the map equals 50,000 cm), Graphic scale (shows scale on a bar, stays accurate if map changes)
Remote-Sensing Tools
The use of technology to record observations from a distance; handheld, aircraft, and satellites capture radio waves, microwaves, infrared energy, and visible wavelengths; Used for a variety of environmental and land-use issues; Spatial resolution (size of the smallest area, or pixel); Spectral resolution (range of wavelengths captured by the sensors)
Aerosols
Tiny particle present in the atmosphere that are so small and light that the slightest air movements keep them aloft (dust particles)
The Earth's Atmosphere
Uniformly surrounds the Earth, held down by gravity, 97% lies within 30 km (19 mi) of earth's surface, 50% lies within 3.8 mil of Earth's surface (Mt. McKinley)
Urban sprawl
Where population exceeds the space that the people live in, people spread out. highways are built
Cylindrical Projection
Wraps a cylinder around the globe so that the paper touches the globe at the equator (Mercator project)
The Greenhouse Effect
absorption of outgoing longwave radiation by components of the atmosphere and reradiation back to the surface, which raises surface temperature, reradiation is also known are counter radiation
daylight saving time
clocks are set ahead by an hour for a part of the year
atmosphere
composed of gas, which protects the earth from harmful radiation
coordinated universal time
derived from atomic time, and provided a day of 86400 seconds in length to match the earth's mean rotation rate with respect to the sun
sun rises in the ____ and sets in the _____?
east, west
parallels
east-west circle on the earth's surface, lying on a plane parallel to the equator
Longitude v. Latitude
latitude = horizontal longitude = vertical
geographic grid
network of parallels and meridians used to find a fixed location on the earth
meridians
north-south line on the earth's surface connecting the poles
What shape is the earth?
oblate-spheroid
absorption
process in which electromagnetic energy is absorbed when radiation strikes molecules or particles in a gas liquid or solid
albedo
proportion of solar radiation reflected upward from a surface high albedo = snow and clouds low albedo = black asphalt
biosphere
represents the earth's living plants and organisms
prime meridian
runs through greenwich, england. 0 degrees longitude
lithosphere
structural rock foundation of the planet's surface
what is human geography?
study of spatial interactions and patterns related to human activity
cryosphere
water in ice form
Solar noon
where the sun casts its shortest shadow, reaches the highest angle