Study Guide 2 Geography
CH.5: Global Temperatures
describe the principal temperature controls:
Latitude- Effects insolation. Isolation decreases as one moves away from the subsolar point- a point that migrates between the Tropic of Cancer and Capricorn. In addition daylength and sun angle change throughout the year, increasing seasonal effects with increasing latitude.
Altitude- High altitude has greater daily range, and has lower annual average. As the atmosphere thins( high altitudes) there is a loss in its ability to absorb and radiate sensible heat.
cloud cover- High albedo, Moderate temperatures – cooler days, warmer nights. At night clouds act as insulation and radiate longwave energy, preventing rapid energy loss.During the day clouds reflect high insolation.
Evaporation- evaporation consumes more of the energy arriving at the ocean's surface than is expanded over a comparable area of land because water is available. An estimated 84% of earth's evaporation is from the oceans.
Transparency- Water is transparent meaning that light travels through it which leads to the distribution of available heat energy over a much greater depth and volume, forming a large energy reservoir. Compared to land which is opaque and light does not penetrate, but absorbs, this heats the grow during exposure but is rapidly lost at night or in the shadows.
Specific heat-is the measure of the heat energy required to increase the temperature of a unit quantity of a substance by a unit of temperature. Is greater for water than for land
Movement- Water’s movement allows the mixing and distribution of available heat energy. Land and the ocean radiate longwave radiation at night, but land loses it more rapidly because it is not moving. We also discuss several other topics like What is the meaning of variable consideration?
Ocean currents and sea-surface temperatures- The gulf stream moves warmer water towards the southern third of Iceland which makes the temperatures much milder then what would be expected for a latitude of 65 degrees North.
Marine vs. continental effects- Continental temperature conditions are more extreme, so land heats and cool more rapidly. Marine conditions are moderate, so water warms and cools slowly.
describe Earth’s Temperature Patterns:
Isotherms- Isotherm is an isoline – a line along which there is a constant value. In this case it portrays a line that connects points of equal temperature creating a contour map pattern of temperature. Thermal equator is an isotherm connecting points of highest mean temperature
variations with seasons
January Temperature Map: Thermal equator(an isotherm connecting all points of the highest mean temperature) movement southward, more pronounced over large continents. Southern hemisphere has little seasonal variation in mean temperatures due to the lack of large landmases and the vast expansing of water. We also discuss several other topics like What are the three aspects of consonant production?
July Temperature Map: Thermal equator movement northward, more pronounced over large continents We also discuss several other topics like A theoretical statement explaining the relationship between two phenomena or variables is known as what?
CH.6 Atmospheric Circulation
•describe three forces driving air movement within the atmosphere:
Pressure Gradient- Drives air from areas of higher barometric pressure(more dense air) to areas of lower barometric pressure( less dense air), thereby causing winds, Without pressure gradient force their would be no wind. Can get wind moving from zero
Coriolis- A deflective force, makes wind that is traveling in a straight path appear to be deflected in relation to earth's rotating surface. Deflects wind to the right in the Northern Hemisphere and left in the southern hemisphere. Without it, winds would move along straight paths between high and low pressure areas. Only affects objects already moving
Friction- Drags on wind as it moves across surfaces: it decreases with height above the surface.Without friction, winds would simply move in paths parallel to isobars and at high speeds. Only affects objects already moving
-These affect horizontal winds
-Gravity is a vertical wind
•Be able to describe and draw patterns of air movement associated with low pressure cells and high pressure cells in the:
Northern hemisphere- –Relative to north pole, earth spins in counter-clockwise rotation. –Deflection of air movement is to the right due to Coriolis
–Low pressure cells rotate counter-clockwise, Higher Pressure cells rotate clockwise. southern hemisphere-–Relative to south pole, earth spins in clockwise rotation. Deflection of air movement is to the left due to Coriolis. We also discuss several other topics like When was the modern state-based international system established?
–Low pressure cells rotate clockwise, High pressure cells rotate counter-clockwise EXAMPLE:
Global Circulation: We also discuss several other topics like What does materialism mean?
Describe and how they vary with seasons over land versus water.
Thermal Equator- The thermal equator is a belt encircling the Earth, defined by the set of locations having the highest temperature. Primarily dictated by solar radiation, also sensitive to land-water heating differences, mountain ranges and ocean currents,
because of this it tends to oscillate near latitudinal equator but not identical to latitudinal equator.
Intertropical Convergence Zone-Area along the equatorial region where solar radiation drives surface heating, causing air to rise and resulting in significant precipitation.The rising air is replaced by horizontal air movement from both the northern and southern hemisphere creating “convergence” along the ITCZ. Summer is a wet season.The location of the intertropical convergence zone varies over time. Over land, it moves back and forth across the equator. Over the ocean it also oscillates, but more subtly, as ocean temperatures modulate the movement. We also discuss several other topics like What is the meaning of appreciative leadership?
–describe and identify locations and their relationship to trade winds, westerlies, and easterlies:
Hadley cells: As rising air along the ITCZ rises it cools and precipitation occurs. Once cooling is significant enough the air begins to descend at higher latitudes (about 30 degrees) in both the northern and southern hemisphere.This air circulates back toward the equator, creating a “cellular” pattern of rotation. This is why they are associated with the trade winds because they start at the ITCZ and then return to it as the trade winds.
Ferrel Cells: Air descends along an area near 30 degrees latitude.Descending air flows to higher and lower latitude as it compresses at the surface.Air flow moving to higher latitude is deflected to the right in the northern hemisphere and to the south in the southern hemisphere, creating the westerlies.
Polar Cells: Cold air descends from the poles to lower latitude. As the air descends it is deflected to the right in the northern hemisphere and to the left in the southern hemisphere, creating the polar easterlies.
–Be able to identify locations of
equatorial lows- warm and rainy, between 10 and 10 . ° N ° S
subtropical highs- Between 20 nd 35 in both hemispheres.Hot, dry air. ° a ° subpolar lows- 60 and 60 , cool and wet ° N ° S
polar highs- 90 and 90 , Cool and dry. ° N ° S
define relative humidity and it’s relationship to air temperature- A ratio(expressed as a percentage) of the amount of water vapor that is actually in the air compared to the maximum water vapor possible in the air at the temperature as the denominator. Warmer air means greater maximum water vapor possible. Colder air means lesser maximum water vapor possible.
Be able to draw the saturation vapor pressure curve and determine dew point temperature for a given air temperature and relative humidity.
Dew point- The temperature at which a given mass of air becomes saturated and net condensation begins to form water droplets. The air is saturated when the dew point temperature and the air temperature are the same TD = T − ((100 − RH)/5)
RH = actual water vapor in the air/Maximum water vapor possible in the air at that temperature × 100
Be able to define the rate at which air cools as it rises for both moist and dry air and how it relates to atmospheric stability.
- Air parcel cools internal as it expands under low air pressure. Air parcel heats internal as it is compressed by higher air pressure. The dry adiabatic rate is the rate at which “dry” air cools by expansion (if ascending) or heats by compression (if descending). The moist adiabatic rate is the rate at which an ascending air parcel that is moist or saturated, cools by expansion. It is unstable because air is rising higher into the atmosphere.
Be able to list and describe mechanisms for air lifting and it’s importance with respect to precipitation.
Convergent Lifting- air flowing from different directions into the same low pressure area is converging, displacing air upward.
Convectional Lifting- when air passes from a maritime source region to a warmer continental region, heating from the warmer land cause lifting and convection in the air mass. Warmer surfaces produce conventional lifting.
Orographic Lifting- Occurs when air is forcibly lifted upslope as it is pushed against a mountain.The physical presence of a mountain acts as topographic barrier to migrating air masses.
Frontal Lifting (Cold and Warm Fronts)- The leading edge of an advancing air mass. A front is a place of atmospheric discontinuity, a narrow zone, forming a line of conflict between two air masses of different, pressure, humidity, speed and cloud development.
Be able to list the ingredients of precipitation formation and mechanisms: Moisture- (lakes, rivers, oceans, moist soils)
Lifting- cool air rising, as it cools it will possibly reach dew point temperature, saturation, and active condensation.
Saturated air - air saturated by water
condensation nuclei- Microscopic particles that always are present in the atmosphere(dust, soot, sulfate aerosols)
list and describe the terms in the water cycle
Evaporation- Process by which a liquid becomes a gas
Condensation-the process of changing from a gaseous to a liquid or state
Precipitation-the falling to earth of any form of water (rain or snow or hail or sleet or mist)
Transpiration-loss of water from a plant through its leaves
Water Table-the top of the saturated zone
Percolation-the slow movement of water through pores in soil or permeable rock
Surface runoff-water which runs along the surface into collection points (streams, rivers, ponds, lakes, ocean, etc)
GroundWater-water found beneath Earth's surface
Infiltration-seepage of water into soil or rock
Discharge-waters that are emptying from one moving source (stream or river) into another moving or still source (river or lake)
Aquifer-a rock layer that stores and allows the flow of groundwater Evapotranspiration-evaporation from plants, and soil
Coalescence-when water droplets fuse to create larger water droplets, or when water droplets freeze into ice crystals
Permeability-a rock's ability to let water through it
Impermeable-a rock that tends to stop the flow of water
Sublimation- direct change from ice to water vapor, or water vapor to ice.
Water cycle-The continuous process by which water moves from Earth's surface to the atmosphere and back
Humidity-the amount of moisture in the air
Psychrometer-Instrument used to measure relative humidity that has two thermometers (wet bulb and dry bulb)
Dew Point-the temperature at which the water vapor in the air becomes saturated and condensation begins
Clouds -Cirrus-Wispy, feathery clouds,Cumulus-clouds that look like fluffy, rounded piles of cotton,Stratus-Clouds that form in flat layers.
Rain Gauge-Open ended tube that collects rainfall
Rain-Most common form of liquid precipitation
Snow-precipitation falling from clouds in the form of ice crystals
Sleet-Ice particles smaller than 5 millimeters in diameter
Hail-Ice pellets larger than 5 millimeters in diameter formed in cumulonimbus clouds by strong updrafts of wind
freezing rain-rain that freezes when it hits a cold surface
Precipitation-any form of water that falls from clouds and reaches Earth's surface Fog-a stratus cloud that forms when air is cooled to its dew point near the ground
Virga-Precipitation that begins falling to the Earth but evaporates before reaching the surface.
cloud seeding-encouraging rainfall by seeding the air with condensation nuclei
Be able to calculate a soil water budget.
Be able to define – and know how they vary with soil types
wilting point-Wilting point (WP) is defined as the minimal point of soil moisture the plant requires not to wilt. Happens when soil starts to become hygroscopic.
field capacity-Field Capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased.
soil water availability- The water available to plants. Soil available water is the difference between water content at field capacity and permanent wilting point.