Physical Geography (GEOG 1301.01)

Test 2: Review

Week of March 28, 2005

 

Chapter 7: Water and Atmospheric Moisture

            71% of earth surface (70% of our bodies)

            mean sea level risen 8-16 in over 100 years

            Oceans = 97%, Freshwater = 3%, Rivers/lakes/streams = 1%

States of water: ice, liquid and vapor (page 184-186)

Properties of Water

            Polarity = hydrogen bonding, sticks to and dissolves things

            Surface tension = things float

            Capillary action = pulls in its neighbors

           

Phase change from liquid to solid water: 9% increase in volume

Relationship between water, heat and energy (30% of energy that powers the general circulation of the atmosphere)

 

Phase changes and caloric absorption and liberation- latent heat exchange is the dominant cooling process in earth’s energy budget- know Figure 7-4 (fill in arrows)

 

Humidity (water vapor content), warm air holds more vapor than cold

Relative humidity: ratio of amount of water vapor in air to holding capacity.  Varies due to evaporation, condensation or temperature changes.

Saturation: At 100% relative humidity, any change in temp (cooler) or addition of more vapor results in condensation (precipitation)

Dew-point temperature: temperature at which a mass of air would become saturated

Cloud- aggregation of tiny moisture droplets and ice crystals suspended in air

Cloud Formation Process (Type of Clouds, page 200-201) Know association of clouds to weather patterns. 

Cumulonimbus- associated with thunderstorms. 

Cirrus- associated with approaching precipitation. 

Stratocumulus- associated with clearing weather.

 

Chapter 8: Weather

Weather- short-term, day to day conditions

Climate- long-term average of conditions with extremes

Air mass- distinctive body of air (source region defines it as cold, moist, tropical, etc.) Defined (classified) by moisture and temperature

Four Atmospheric Lifting Mechanisms (page 215- Figure 8.6):

·        Convergent- air flows toward an area of low pressure (along ITCZ)

·        Convectional- stimulated by local surface heating (create afternoon showers)

·        Orographic- air forced over a barrier (rain shadow- dry side of mountain)

·        Frontal- along leading edges of contrasting air masses

 

Simple midlatitude cyclonic life cycle (motion) generated by:

1.      pressure gradient force

2.      coriolis force

3.      surface friction

Midlatitude Cyclone- (wave cyclone) conflict between contrasting air masses, dominate weather patterns in middle and higher latitudes of Northern and Southern Hemispheres

Cyclogenesis- atmospheric process of low pressure system development and strengthening

Formation of a Tornado- from mesocyclone circulation and cold front interaction

 

Chapter 9: Water Resources

 

Energy exchanges between water and atmosphere drive weather systems.

Water flow links the spheres through exchanges of energy and matter.

(Precipitation = receipt) and (evapotranspiration = expenditure)

 

Hydrologic Cycle:

Know all of the components and their percentages (page 247)

Ocean = 86% of evaporation

Land = 22% of precipitation (20% of moisture from ocean)

Runoff is 8% (of the 20%- above- from ocean)- overland flow and streamflow

 

Soil-water Budget:

Measures precipitation input against demands of evaporation, transpiration and soil moisture storage

Use the soil-water balance equation to model this (PAGE 234)

Precipitation: The input (moisture supply) into the equation = rain, sleet, snow, etc.

Actual Evapotranspiration = evaporation (movement of water from wet to air) and transpiration (plant cooling process)

Potential Evapotranspiration = PE = The amount of evapotranspiration that could happen given optimal moisture conditions.  It needs adequate precipitation and soil moisture supply

Soil Moisture Storage = Volume of water stored in soil accessible by plant roots

Soil moisture has 2 kinds of water:

1.      Hygrosopic- (molecule-thin layer of water, unavailable to plants) and

2.      Capillary- (accessible to plants- available to plants)

Field capacity- amount of water available to plant after drainage (runoff and percolation)

Wilting point- condition of soil when only remaining water is unextractable (hygroscopic) by plants

 

Goal of irrigation: avoid soil moisture deficit and reduction of plant growth

 

Understand the soil water budgets on pages 240-241.

 

Groundwater:

Aquifer: rock layer that is permeable to groundwater flow- water-bearing rock strata.  Bordered by an aquiclude.

Water table: upper limit of water that collects in the zone of saturation (where subsurface water accumulates.)

 

Review sections on Overuse and Pollution of groundwater (page 248-252.)

 

Chapter 10: Global Climate Systems

 

Climate is a conceptual, statistical construction from these measured weather elements.

 

Global climate change may be producing:

·        record global temperatures

·        glacial ice melt

·        changing soil-moisture conditions

·        affecting crop yields

·        disease patterns

·        species distribution

·        reef and fisheries health

·        permafrost thawing.

 

a)     10% less soil moisture

b)     Warming of temperatures of 3.6 F to 6.3 F

c)      Poleward shift of climates 90 to 350 miles

d)     Sea level rise of 4-20 feet

e)     Changes in climate and natural vegetation during the next 50 years may exceed total of all changes since peak of last ice age (18,000 years ago.)

 

Classification – process of grouping data in related categories

Empirical Classification: based upon statistical data of observed effects

·        Thornthwaite’s Water-budget approach (chapter 9)

·        Koppen’s climate classification

 

Genetic Classification: based upon causative factors

 

Cfa and Cwa climates support large populations

 

 

PRECIPITATION IS THE KEY CLIMATE CONTROL FACTOR.

 

Temperature and precipitation (empirical) are the keys to climate classification (see Figure 10-3).

 

Climate Designations: Know page 267-68 and review Continental US (Figure 10-4 and 10-5.)

Cfa and Cwa climates support large populations: Where are they?

 

Tropical Climates- 36% of Earth’s surface- most extensive climate category

 

Carbon Dioxide CO2: (64% of warming trend and increasing .5%/year) and H2O vapor are the principal radiatively active gases (causing greenhouse effect.)- Transmit heat but delay heat-energy loss to space.  We aggravate this by burning of fossil fuel/deforestation

 

Consequences of Global Warming: Regional changes in temperature, precipitation, soil moisture (10% less) and air masses.  Monoculture agriculture high risk.  Need more energy, water and resources to adapt.  Climate shift of 90 to 350 miles toward the poles.  Major species redistribution (30% change in forest cover.)  Health impacts include malaria, yellow fever, etc all at subtropical and mid-latitude areas.

 

Climograph- graph that shows monthly precipitation and temperature

 

Sample Essay Questions

 

1. Explain the concept and components of the soil-water balance equation.  Write the equation.  (page 249)

 

2. Draw, label and explain a graph of the water budget.  Show the components of  PRECIP, POTET, surplus, etc and their relationship to rainfall and temperature.  Use Texas as your example. (page 255)

 

3. What is a “climograph”?  Draw a sketch of the climagraph for Central Texas.   (page 283/287)