Geography exam one chapters 1-4

Surface energy balance calculation

+SW↓-SW↑+ LW↓ - LW↑ = net radiation

The electromagnetic spectrum and energy: Long Wavelengths

- 'Cool' objects radiate long wavelengths (Earth: 59o F→Infrared light) -(Vis& UV) The Earth sheds energy to space through Longwave radiation (IR light)

The electromagnetic spectrum and energy: Short Wavelengths

-'Hot' objects radiate short wavelengths (Sun: 11,000o F→UV & Visible light) -The Sun adds energy to the Earth through Shortwave radiation

The electromagnetic spectrum and energy

-All objects radiate electromagnetic energy -All radiation is the same, only wavelengths are different -The Earth's temperature is controlled by an 'energy budget' (see Chapter 4)

Air Pressure

-Atmosphere has a weight: about 14.7 pounds per square inch (1013mb) -This weight is felt as a pressure. -Swimming pool analogy: water squeezes you; doesn't push you down. As you go to higher elevations, less atmosphere is above you; pressure is less. -Air can be compressed: Sea level air more compressed than at higher elevations. Therefore, air pressure decreases quickly as you get to higher elevations.

Global Warming & Greenhouse effect: CO2

-CO2 absorbs longwave light. -prevents night cooling -prevents winter cooling -warming in high latitudes first

Heat moves in three ways:

-Conduction -Convection / Advection -Radiation (ch. 2): hot object SW, cool LW

Measuring Air Temperature

-Environmental Lapse Rate (ELR): the temp of the atmosphere at different elevations. We measure it using weather balloons. -Why does warm air rise? It is warmer than the surrounding air (the ELR) so it is less dense. If air is colder and more dense than the ELR, it sinks. -Temperature inversions: warm air is above cool air. Air can't rise above this layer

Geographic Information Science (GIS)

-Geographic Information Systems or GIS are used to record information on to maps -Both GPS and GIS are useful in managing land in the high country -GIS is a computer-based system used for capturing, storing, analyzing, and visualizing geospatial data

Global Positioning Systems (GPS)

-Global Positioning Systems or GPS are used to find the exact location of things -GPS is a satellite-based navigation system that uses satellites that orbit the Earth to send information to GPS receivers that are on the ground. -Both GPS and GIS are useful in managing land in the high country

Adiabatic Cooling & Heating

-If air is sitting still at one elevation, it stays the same temperature....but if you lift it, it expands and cools down. "adiabatic cooling"...if it is pushed down, it gets squeezed and warms up. "adiabatic warming"

Variable Gasses: Carbon Dioxide (CO2)

-Increasing concentrations since Industrial Revolution -Seasonal variations due to plant growth and decay.

Longitude lines

-Measures East-West location -Based on Earth's rotation: (15o/hour) -Requires a good clock that can keep time while traveling (Harrison, 1735) -Requires a reference point (Prime Meridian: Greenwich, England) -AM time→East; PM time→West

Measuring the Earth, Latitude

-Measures North-South location -Has been measurable for thousands of years -Angle between Polaris and horizon

Other ways of defining Geography:

-Regional Geography -Spatial Science

Sun Angle

-Sunlight is perpendicular at only 1 point. -At all other points, the sun is at an angle. -Sunlight is stronger when perpendicular. -The closer you are to the sub-solar point, the more solar energy. -Summer→sunlight is strong. -Winter→sunlight is weak. -Autumn, Spring→in between.

Definitions of Geography

-The study of people, their environment, and the interaction between the two

What causes the Seasons?

-The tilt of the Earth's axis, and the Earth's orbit. -Sun Angle

Radiation can do one of the following things when it comes in contact with matter:

-Transmission -Reflection -Absorption

Absorption

radiation energy is added to the matter to form heat

Transmission

radiation passes through Refraction: path of light bends slightly as it is transmitted.

Unusual properties of clouds

reflect S.W. : albedo is 95%! absorb L.W.: can absorb almost all infrared light. radiate L.W.: clouds radiate longer infrared wavelengths.

-SW↑

Reflection

Perihelion

the day that the Earth is closest to the Sun: January 3rd.

Aphelion

the day that the Earth is farthest from the Sun: July 4th.

Plane of the ecliptic

the imaginary flat space formed by the Earth's orbit.

Subsolar point

the point where the Sun's rays are perpendicular to the Earth's surface.

Revolution

to move in a circle, or to orbit (1 Earth revolution = 1 year ≈ 365 days)

Rotation

to spin on an axis (1 Earth rotation ≈ 1 day ≈ 24 hours)

Thermosphere

warms as you go up (absorbs high-energy solar radiation)

Stratosphere

warms as you go up (due to OZONE O3 absorption of UV light)

- LW↑

From ground

Spatial Science

Geography is an abstract study of how processes operate over space

Regional Geography

Geography is the study of different places and how different processes operate there

Urban Heat Islands

-Urbanized areas that experience higher temperatures than outlying areas. Structures such as buildings, roads, and other infrastructure absorb and re-emit the sun's heat more than natural landscapes such as forests and water bodies. -Pavement & metal: less evaporative cooling, lower albedo, leads to higher temps -Impervious surfaces: less water absorbed, more runoff -Buildings slow wind; less advective heat loss, higher energy use -Particulates: more rain, more IR re-radiation, reduced insolation; haze

Remote Sensing

-anything where you are measuring from a distance • Satellite • Airplane • UAV

Variable Gasses

-concentration varies over space or over time. -Carbon Dioxide (CO2) -Water Vapor (H2O) -Ozone (O3)

The Layers of the Atmosphere: 4

-defined by temperature changes (the ELR). -Troposphere -Stratosphere -Mesosphere -Thermosphere

Atmospheric Composition: Non-Variable Gasses: (99.9%)

-do not vary in concentration in the homosphere. -Nitrogen (N2) 78% -Oxygen (O2) 21% -Argon (Ar) 0.9%

Variable Gasses: Water Vapor (H2O)

-humidity measures water vapor concentration -mostly found in Troposphere: if it is too cold, it freezes & falls -large spatial variation -water vapor is less dense than dry air (HOH vs. OO or NN)

Variable Gases: Ozone (O3)

-naturally found in stratosphere.high-energy radiation forms -Oxygen radicals (O) in thermosphere -Oxygen radicals drift to stratosphere and join O2 to make O3. -Water vapor converts O3 into O2. -Stratospheric Ozone absorbs UV light: makes life on land possible! -Tropospheric ozone forms due to pollution; is harmful to breathe. Nitrogen oxides (NOx), Volatile organic compounds (gasoline fumes), and sunlight, in an absence of water vapor, produce tropospheric ozone.

Reflection

-radiation 'bounces' away -Albedo: a measure of how much solar radiation is reflected -Scattering: random reflection in all directions to form diffuse light

Longitude Method:

1) set watch to Greenwich Mean Time (GMT, similar to UTC) 2) travel to new location. 3) at local solar noon, what time is it at the Prime Meridian? 4) calculate location (time difference in hours * 15o /hour) AM time→East; PM time→West

Longitude method example: You set your watch to Greenwich Mean Time, then travel around the world to someplace new. You wait until the Sun is directly overhead and check your watch. Your watch says that it is 9 am. What is your longitude?

12-9= 3 (9 am to noon is 3 hours) 3 hours times 15 =45 degrees east

Latitude example: -If Polaris is 39 degrees above the horizon your latitude is ____ degrees

39 degrees

Longitude method example: The Sun is directly overhead at 4pm UTC. What is your longitude?

4pm to noon = 4 4 times 15 = 60 degrees west

Convection / Advection

?-Convection is the movement of a fluid, typically in response to heat. -Advection is the movement of some material dissolved or suspended in the fluid. -So if you have pure water and you heat it you will get convection of the water.

Radiation (ch. 2): hot object SW, cool LW

?-the transfer of energy between two objects by electromagnetic waves. -Heat radiates from the ground into the lower atmosphere

Conduction

?-the transfer of heat from a warmer object to a colder object through molecule interaction. -As the sun heats the ground, energy is transferred to the atmosphere by conduction.

LW

Earth/Atmosphere, LongWave, Infared Light

+ LW↓

From atmosphere

+SW↓

Insolation

Solstices

June 22: Sub-solar point is at the Tropic of Cancer (23o N) Dec 22: s.s.p→the Tropic of Capricorn (23o S) As the Earth rotates, the S.S.P. moves around the world

Equinoxes

March 20, Sept 22, sub-solar point is at equator (0o N)

Latitude example: -Where are you located if Polaris is directly overhead?

Northpole

The parts of Geography:

Physical G., Human G. & Techniques

SW:

Sun, ShortWave, Visible/UV light

Length of Daylight: Arctic and Antarctic Circles:

Winter solstice: Sun never rises. Summer solstice: Sun never sets. Comparing relative length of daylight for any day of the year. Comparing relative length of daylight for any two points on Earth.

Circle of Illumination

a line that divides the Earth into lit and unlit halves; sunrise and sunset

Mesosphere

cools as you go up

Troposphere

cools as you go up

Length of Daylight: Equinox

everyone gets 12 hours of daylight. Winter: under 12 hours of daylight Summer: over 12 hours of daylight The equator always gets 12 hours of daylight