Lab Exam #1 terms

conformal maps

preserves angles/shapes

equivalent maps

preserves size

map scales

displays the relationship between the distance on the map and the actual distance on the ground

verbal scales

expressed with words “one inch represents one mile”

graphic scales

bar graph showing distance; measure distance on the map and compare it to the drawn scale

fractional/ representative scale

1 unit on the map= 50,000 units on the ground ex: 1:50,000; can be any unit as long as it’s the same

Isolines

lines that connect points of equal value on a map

Isobars

equal atmospheric pressure

contour lines

equal elevation

contour interval

difference in elevation between two contour intervals

index contour

a wider, darker contour

vertical exaggeration

horizontal/vertical

Locations (GIS)

positions in two dimentional space

attributes

Qualities or Quantities, such as city names, or population figures

Vector

a representation of the world using points, lines, and polygons

Raster (GIS)

A representation of the world as a surface divided into a regular grid of cells

polygon (GIS)

countries, states, oceans

line (GIS)

roads, rivers, rails

Four main factors controlling the seasons

1. Rotation

2. Revolution

3. Inclination

4. Polarity

Rotation

earth completes one roation on its axis every 24 hours

revolution

every 365.25 days the earth completes one revolution around the sun

inclination

the axis the earth’s rotation is tilyed 23.5 degrees relative the plane of the ecliptic

polarity or parallelism

earth’s rotation axis is always pointed in the same direction (towards the north star) while revolving around the sun

special days of the year

march and september equinoxes, june and december solstices

March and September Equinoxes

Vertical rays of the sun strike the equator

The sun’s rays are tangent (“skimming”) at the North and South Poles

The circle of illumination bisects all parallels-all latitudes experience 12 hours at night and 12 hours of day

December Solstices

December 21st

Vertical rays of the sun strike the tropic of capricorn (23.5 S)

Sun’s rays are tangent at the Arctic Circle (66.5 N) and Antarctic Circle (66.5 S)

North of Arctic Circle experiences 24 hours of night while South of Antarctic Circle experiences 24 of daylight

June Solstice

June 21st

Vertical rays of the sun strike the tropic of cancer (23.5 N)

Sun’s rays are tangent at the Acrtic Circle (66.5 N) and Antarctic Circle (66.5 S)

North Pole (90 N) leaning toward the sun

North of Arctic Circle experiences 24 hours of daylught while South of Antarctic Circle experiences 24 of darkness

Seven Special Parallels

North Pole- 90 N

Arctic Circle- 66.5 N

Tropic of Cancer- 23.5 N

Equator- 0

Tropic of Capricorn- 23.5 S

Antarctic Circle- 66.5 S

South Pole- 90 S

Declination of the Sun

the latitude receving the vertical rays of the sun, rays striking the surface at the right angle

• without earth’s tilt, declination would always be 0

• Solar declination is 0 on the equinoxes

Solar Altitude (SA)

the apparent elevation of the noon sun in the sky

• its the angle of the noon sun above the horizon

• this can be calculated with the following equation SA= 90-Arc Distance (AD)

Arc Distance

the number of degrees of latitude between the latitude in question and the declination of the sun

Insolation

Incoming solar radiation; the rate at which solar energy strikes a surface (in intensity)

intensity

amount of energy recieved during a given period of time in a given area

Solar constant

the amount of insolation that reaches the earth’s upper atmosphere 1372 W/m²

3 factors that determine actual daily insolation at the surface

1. angle of incidence of incoming radiation

2. length of day

3. obstruction of atmosphere

angle of incidence

the angle at which the sun’s rays strike the surface of the Earth

five factors that are important to worldwide temperatures

• latitude

• land-water contrasts

• ocean currents

• wind patterns

• altitudes

latitude

the most basic control of temperature; higher latitude=lower temp

land-water contrasts

land heats and cools fast water heats and cools slow

east coast of continents

warm water

west coast of continents

cold air

Average lapse rate

temperature decreases 3.6 F per 1000 feet of vertical change

6.5 degrees C per 1000 meters

rising or warm air

low pressure

sinking or cool air

high pressure

dynamic lows

lows caused by strongly rising air

thermal lows

lows caused by warm surface conditions

dynamic highs

highs caused by cold surfaces conditions

milibar

a measure of force per unit area

inches of mercury

the height of a column of mercury in a liquid barometer

troughs

the bottom of the depression before it goes back up in pressure

ridge

the pack of the pressure before it begins to decline

pressure gradient force

the force created by a change in air pressure over a given distance

change in air pressure = wind

wind moves down the gradient

wind always moves from high to low pressure

Coriolis “Force” / effect

the pattern of deflection taken by objects not firmly connected to the ground as they travel long distances around earth

• impacts winds above 3300 ft (1000 meters)

• north- right

• south- left

friction

only at surface , slows wind at surface or coriolis force is reduced

anticyclonic wind (northern hem)

diverges clockwise out of a high

cyclonic wind (northern hem)

converges counterclockwise into a low

humidity

the amount of water vapor in the atmosphere

mixing ratio

the amount of water vapor in the air per kilogram of dry air (g/kg)

specific humidity

grams per kilogram of air, including vapor

absolute humidity

mass of water vapor per cubic meter of air

saturation mixing ratio

how much water vapor the air is capable of holding (changes based on temp)

water vapor capacity

when the temperature increases, so does the water vapor capacity

relative humidity

actual water vapor content (mixing ratio) / water vapor capacity (saturation mixing ratio)

dew point

the temperature at which a parcel of air would be at 100% RH (or completely saturated)

Fronts

transition zones develop to seperate the two air masses

cold front

the beginning of the cold air masses

warm front

the begining of the warm air masses

weather changes with passing cold front

• temp decrease sharply

• wind direction shifts (converging counterclockwise)

• the front is in a pressure trough, pressure falls as the front approaches and rises after it passes

• clear skies ahead at the front are replaced by cloudiness and precipitation at the front - to be replaced again by clear skies after the front moves away