Geography 131 Exam 1 UTK

Parallels

concentric circles

parallel

equal distance

different lengths

Meridians

pole to pole

not parallel

converge at poles

Latitude

measure angle of equator

0 degree @ equator

90 at poles

negative in southern hemisphere

Longitude

measure of angle from the Prime Meridian

Greenwhich, England

0 @ prime meridian

increases east (+) to west (-)

180 at date line

Knoxville Coordinates

35°58'22"N 83°56'32"W or 36°N 84°W

Tilt of Earth

23.5°

GPS

location info to help define spatial relationships

24 satellites on 6 different planes maintained by US. Gov.

Distance from multiple satellites tells location

trilateration

Remote Sensing:Passive Systems

measure energy being emitted naturally (heat, light, etc.)

Remote Sensing:Active Systems

direct a bean of energy and measure amount of return

GIS (Geographic Info Systems)

represented as data layers

Structure of Earth's Atmosphere

each "sphere" wraps the earth successively in a spherical shape

spheres are separated by pauses

gas molecules are more abundant near the surface due to gravity

Troposphere

closest to earth's surface

all weather occurs here

"Tropo"=mixing

contains 70% of atmospheric mass

Stratosphere

10-50km

where commercial jets fly

contains the ozone layer

"stratified"->layered

temp. increases with height

Mesosphere

50-80km

"meso"=in the middle

temp. decreases with height

upper meso.=coldest part of earth's ecosystem

shooting stars

Thermosphere

80-100km

"thermo"=heat

temp. increases with height

where northern lights are found

Composition of Atmosphere

mostly nitrogen, oxygen, and argon

trace amounts of CO2 and methane

Energy

ability to do work

Kinetic Energy

movement

in atoms more motion=warmer

Potential Energy

contained within molecular bonds

Latent Energy

energy related to state of matter

type of potential energy

Warming

gain energy from surroundings

Cooling

loss of energy to surroundings

Heat (energy)

transferred from higher temp. to lower temp. objects

Conduction

energy transfer via direct contact between warmer and cooler objects

direct contact

Radiation

energy transfer by electromagnetic waves

E.g.: The Sun

Convection

vertical heat transfer by the flow of a material (convection cell)

E.g. thunderstorm

Advection

energy transfer by moving mass sideways

e.g. wind

Electromagnetic Radiation

energy radiated from charged particles

some visible

different wavelengths and frequency

Stephan-Boltzman Law

the amount of EMR emitted by an object increases greatly with temperature

(warm objects emit more EMR than cold ones)

Earth EMR Emission

283K

Your EMR emission

310K

Sun's EMR emission

6,000K

Wavelength Ranges

variation in wavelengths and amounts because vibrations vary within objects

Wien's Law

relationship between temperature and wavelength

cool(slow and long wave)

warm (short and fast wave)

aka: warm objects emit shorter wavelengths and vice versa

Peak Wavelength: Exponential Relationship

peak wavelength decreases rapidly for warmer objects

Infrared (IR)

longer wavelengths

Visible Light (VL)

most of Sun's energy at these wavelengths

Ultraviolet (UV)

more energetic than VL

colors within visible light have different wavelengths

Red=longest

Purple=shortest

Energy reaching earths

visible light and UV

energy leaving earth

mostly Infrared

Insolation

shortwave radiation from the Sun

Solar Constant

average amount of insolation (341 watts/m^2)

Perihelion

closest to sun in January

Aphelion

farthest from sun and July

Sun Angle

angle between sun and horizon

Zenith Angle

how far sun is from the sub solar point

Beam Spreading

insolation from lower angle must spread across more surface

(controlled by latitude)

Atmospheric Attenuation

insolation from low angle has to make it through more atmosphere

(controlled by latitude)

Latitude&Sun Angle: Equator

high sun angle= high energy

Latitude&Sun Angle: Mid-latitudes

just right

Latitude&Sun Angle: Poles

low sun angle = more attenuation and spreading = less energy

Sun Angle and the Seasons

earth is tilted as it revolves around the sun which dictates the sun angle and day length at a given latitude causing it to change over the course of a year

Why we have seasons: December

North Pole is tilted away from the sun (N. Hem. Winter)

South Pole is tilted toward the sun (S. Hem. Summer)

Why we have seasons: March and September

spin axis is not pointed toward or away from the sun

transitional seasons

Why we have seasons: June

North Pole is tilted toward the sun (N. Hem. Summer)

South Pole is tilted away from the sun (S. Hem. Winter)

Solar Declination

latitude where the sun us directly overhead on a specific day

sun angle=90°

ranges from Tropic of Cancer to Capricorn

Circle of Illumination

separated night from day

pole faces away from sun in winter (24hr darkness)

pole faces sun in summer (24hr daylight)

Polar Night

all latitudes poleward of the Circles

24hrs. 6 months

90°N&S one sunrise and sunset (at Equinox)

Gases

recall major trace gases in atmosphere

Solid Particles

small enough particles can be suspended

Cloud Droplets

atmospheric components interact with insolation and outgoing radiation

Transmission

transparent to radiant energy

Absorption

retains some energy

Reflection

some radiant energy bounces off Albedo

Albedo

the percentage of incoming sunlight reflected from a surface

Scattering

energy strikes and goes in various directions

Interaction os insolation with atmosphere

shortest wavelengths intercepted higher

ozone intercepts most UV

Ozone

gas molecule with 3 bonded oxygen atoms

abundant in stratosphere

harmful in the troposphere

photodissassociation

how ozone forms

ozone in stratosphere

absorbs harmful UV-B radiation

Ozone Hole

thinning of the ozone layer in the Antarctic region

destroyed naturally and by human activities (CFCs)

Insolation reaching the surface

49% absorbed by the surface, heating it

20% absorbed

31% lost to space from reflection and scattering

Insolation Pathways Reaching the Surface:Snow

high albedo

40-95%

Insolation Pathways Reaching the Surface: Forests

10-20%

Insolation Pathways Reaching the Surface:Grasses

15-25%

Insolation Pathways Reaching the Surface: Water

7% for low zenith

60% for high zenith

Insolation Pathways Reaching the Surface: Crops

20%

Insolation Pathways Reaching the Surface: Bare Soil

5% if wet and dark

40% if dry and light

Insolation Pathways Reaching the Surface: Sandy Desert

30%

Global Energy Budget

Planetary Albedo=31%

-Scattering=7%

-Energy Reflected by CLouds=20%

-Energy reflected by surface=4%

Energy Absorbed by Atmosphere=20%

-absorption by dust and molecules=17%

-absorption by clouds=3%

Energy absorbed by the ground=49%

What happens when energy reaches the surface?

insolation can be converted to other forms of energy

latent heat is stored in water and can be released later

sensible heat warms our earth and atmosphere

earth absorbs shortwave and radiated longwave

Earth's estimated energy balance

if too much leaves, the earth cools

if too much absorbs, earth with warm

Sensible Heat

heat transferred from more energetic and molecules in a warmer to cooler object

What is Temperature

average kinetic energy of the molecules in an object

Measuring Temperature

mercury thermometer

infrared thermometer

radiosonde(weather balloon)

Who reports surface temp

mostly on land

densely populated areas

more developed regions

Boiling point

212°F

100°C

373K

Room Temperature

77°F

25°C

298K

Freezing Point

32°F

0°C

273K

Fareinheit to Celsius

C=5/9 * (F-32)

or quick estimate-> F-30 then /2

Celcius to Fareinheit

F= (C*9/5) +32

or quick estimate-> C*2+30

Kelvin

an absolute temp scale

Celcius to Kelvin

K= C+273

Latent Heat

energy released or absorbed during phase changes

Evaporation

Liquid to Gas

Sublimation

Solid to Gas

Latent Heat of Fusion

melting and freezing

Latent Heat of Sublimation

sublimation and deposition

Latent Heat of Vaporization

condensation and evaporation