ENVS 203- Test 1 Flashcards
What is physical geography?
the spatial analysis of all the physical elements and process systems that make up the environment.
What are the main subfields of physical geography?
- place
- location
- region
- movement
- human-earth relationships
Shape of the Earth?
Shape-geoid shape. 26 miles wider than tall
Meridians Vs. parallels?
Meridians- line connecting all points along the same longitude(north to south) 180 degrees east. 180 degrees west
parallel- (east to west) 80 degrees (north pole=90 degrees)
Location of poles, equator, tropic of cancer, capricorn, and prime meridian?
Poles= 90 degrees
tropics= 23.5 degrees
prime meridian= 180 degrees
Time zones: how many? How much time and space does each zone cover?
24 time zones, each time zone= one hour apart. Earth rotates 360 degrees in 24 hours. so, each time zone covers 15 degrees of longitude
Where is the international dateline?
at about 180 degrees longitude. it marks the transition from one day to another on earth
crossing from E to W = +1 day
crossing from W to E = -1 day
Scale? (large vs small scale maps)
Small scale maps are greatly reduced that shows larger area with less detail
large scale maps are closer to reality and show smaller area with more detail
Projections?
always introduce distortion
- shapes
- distances
- angles
- sizes
What are GPS, GIS, and remote sensing?
GPS-modern mapping tech. doesn’t send out a signal, it is just a receiver
GIS- geographic info system. using comps. to do more complicated mapping, Different layers
remote sensing=info about a distant subject without having physical contact
Rotation vs. revolution of the Earth?
rotation? 24 hours= 1 day. counterclockwise
revolution= orbit around the sun, counterclockwise 1 year to make complete rotation
What is the circle of illumination?
the great circle of the earth that is the border between night and day.
Earth’s orbit-what and when are the aphelion and perihelion?
aphelion- earth is this when it’s farther position from the sun, during the northern hemisphere summer on july 4th
perihelion- earth is this when its closest position to the sun. during the norther hemisphere winter on jan 3rd
What is the plane of ecliptic?
flat plane on which the earth travels as it revolves around the sun
What is the Earth’s axial tilt?
relative to a line running perpendicular to the plane of the elliptic. earths axis is tilted 23.5 degrees
What is axial parallelism?
earths axis maintains a constant orientation during revolution around the sun. tilt doesn’t change
Why do we have seasons?
The primary reason is because the earth’s axis is tilted
Why do we have opposite seasonal patterns in the northern and southern hemispheres?
because of the tilt in the rotation of earth
*What is the sub solar point? Where does it occur over the course of a year?
Subsolar point= the point on earth where the sun angle is 90 degrees
What is solar declination
63 degrees
What are the solstices and equinoxes?
Equinoxes= subsolar point at equator. circle of illumination cuts through poles. 12 hours of daylight everywhere
What is atmospheric pressure?
the weight (force over a unit area) of the atmosphere
How and why does atmospheric pressure change with altitude?
gravity compresses it more near the earth’s surface
What and where are the heterosphere and homosphere?
Heterosphere- from 300 miles to 50 miles above the surface. .001% of atmospheres total mass. gases are unevenly mixed. gas layered by atomic weight.
Homosphere-from surface to 50 miles above. gases are generally evenly blended.
Atmospheric compostision- what are the primary stable and variable/trace gases in our atmosphere?
Constant gases= nitrogen, oxygen, argon.
Variable and trace gases= carbon dioxide, ozone, water vapor
Carbon dioxide- where does it come from and what does it do?
Natural bi-product of life processes.
it traps heat within the atmosphere
Water vapor- where is it highest and lowest? what does it do?
Effects incoming solar radiation. absorbs and stores heat from radiation of the sun and earth. 0-4% of atmosphere, avg. =2%. least over deserts and polar regions, most abundant over tropical rain forests. Warmer air can hold more water vapor
be able to describe (and draw) the atmosphere temp profile?
c
What is the normal lapse rate?
the avg rate of temp decrease with increasing altitude in the lower atmosphere.
What is the ozone layer? Why doe we care about it? what is the ozone hole?
12 to 30 miles above the surface. the region of the atmosphere where ultraviolet wavelengths are principally absorbed and converted into heat. its thinning and depletion relate to human use of CFC’s and other compounds.
describe the mechanisms of heat transfer-radiation, conduction, convection, latent heat
Radiation= the transfer of energy through air, space or matter. Conduction= the molecule to molecule transfer of heat energy as it diffuses. Convection= the transfer of energy by movements of strong vertical motion. Latent heat= the energy absorbed or realesed during a phase change with no change in temp.
What is the relationship between the heat of an object and the wavelengths of energy emitted by that object?
c
What is insolation? Where is it highest?
the incoming solar radiation that is intercepted by earth.
What is albedo? How does it vary across common land cover types?
Reflectivity of a surface described as its
albedo
dark surfaces are low, brighter surfaces are high
What is the greenhouse effect? what are the most important greenhouse gases?
Part of the longwaveradiation from Earth is absorbed and then emitted by gases in the lower atmosphere
Doesn’t actually work
exactly like a greenhouse
Carbon dioxide, methane, water vapor are powerful greenhouse gases
What is the effect of clouds on temp?
increased and decreased temperature
What is earths avg albedo?
31
What percentage of insolation is directly absorbed by the earths suface?
25
How does Earth’s every budget vary with latitude?
These energy imbalances are transferred through winds, ocean currents, and weather systems
Heat vs. temp
Heat: a form of energy, flows from warmer to cooler objects.
Temperature: a measure of the average kinetic energy (motion) of individual molecules in matter
Sensible heat vs latent heat
Sensible heat: heat exchanged from warmer to cooler objects that changes the temperature of the object(s).
Latent heat: heat exchanged from warmer to cooler objects that does not change the temperature of the object(s
Temp controls (how they work and what their effect is)
- latitude
- elevation
- cloud cover
- land-water heating differences
latitudes: Day length and sun angle change more over the year as you move to higher latitudesHigher latitudes have lower average temperatures and higher variability.
Thus, as you go from equator to poles, you generally from continually warm to seasonally variable, to continually cold climates
altitude:Air temperature decreases with altitude in the troposphere Remember the normal lapse rate?
Density of the atmosphere also decreases with altitudeHigh elevation lower average temperatures
cloud cover- Nighttime clouds serve as insulation preventing rapid energy loss. Daytime clouds reflect isolation decreasing maximum temps.Increased cloud cover = warmer nights/winters, cooler days/summer; and thus decreased diurnal and annual temperature ranges
What is an isotherm?
Isotherm: an isoline(a line along which there is a constant value) that connects points of equal temperature
What is the thermal equator anyhow does it move over time?
Thermal equator: an isotherm connecting all points of highest mean temperature
Annual temp range. What controls this?
distance to the ocean
Thermosphere?
The “heat sphere”
Corresponds to heterosphere
50-300 miles above surface
Thermosphere ends and exosphere begins at the thermopause
Temperature increases with altitude due to intense solar radiation
But not a lot of heat because there are so few molecules
Mesosphere?
The “middle sphere”
30-50 miles above surface
Mesosphere ends and thermosphere begins at the mesopause
Mesopauseis the coldest portion of the atmosphere
Very low atmospheric pressure
Temperature decreases with increasing altitude
Stratosphere?
The “stratified (layered) sphere”
11-31 miles above surface
Stratosphere ends and Mesosphere begins at the stratopause
Temperature increases with increasing altitude
Stratosphere is the location of the ozone layer
Troposphere?
Tropofrom the Greek word Troposmeaning change or turn
The “changing sphere”
The layer in which life and weather occur
Troposphere ends and Stratosphere begins at the tropopause
Altitude of tropopausevaries with latitude and season
Temperature decreases with increasing altitude
Potential energy pathways for insolation: transmission
Transmission:
Passage of energy through a medium with no change in energy (i.e. atmosphere or water)
Potential energy pathways for insolation: scattering
Scattering:
Redirection and deflection of energy by gases or particulates with no change in energy
Small gas molecules scatter shorter wavelengths of light
Low-angle rays pass through more atmosphere, and thus experience more scattering
POtential energy pathways for insolation: refraction.
Refraction: redirection of energy as it passes from one medium to another Change in speed = bending Responsible for rainbows & mirages Adds ~8 minutes of daylight to each day
Potential energy pathways for insolation: absorption
Absorption:
assimilation of radiation by molecules and conversion of energy from one form to another
Absorption = increased temperature of absorbing surface
Earth’s surface re
-radiates absorbed energy at longer wavelengths
Potential energy pathways for insolation: reflection
Reflection:
energy returned directly back to space without being changed
Earth’s surface and clouds
both reflect insolation
Temp-controls: land/water: evaporation
Remember latent heat?
Evaporation removes heat from the surrounding environment, stores it as latent (hidden) heat
84% of all evaporation is from the oceans
Temp-controls: land/water: transparency
Solid ground is opaque
Water is transparent
Light can therefore penetrate further through a column of water than of land
Below the surface of land, temperatures remain fairly constantLight can pass through water to an average depth of 200 feet in the ocean
This photic layer (illuminated part of the ocean) is as deep as 1000 feet in some places
Temp-controls: land/water: movement
Land is rigid, solid
Water is fluid
Ocean currents and convection mix cooler and warmer water
Heat is therefore spread over a greater volume
Winter solstice?
dec 21
north pole= 0 hr of daylight
equator= 24 hour of daylight
(on right of sun)
Vernal equinox?
march 21
north pole= sun rising
south pole=sun setting
(above sun)
Summer solstice?
june 21 north pole=24 h daylight equator= 12 south pole= 0 hr daylight (on left side of sun)
Autuminal equinox?
sep 22 north pole= sun setting equator= 12 h south pole= sun rising (on bottom of sun)
