Unit 2 Exam 5a-7d

5a- driving forces of wind

-gravity

-pressure gradient force (pressure differences between areas, causes air to blow from H to L pressure)

-coriolis force (wind veers during process of moving from H to L pressure. NH=toward right, SH=toward left

-friction force (wind movement altered by frictional drag of earths surface, speed is slowed, direction is altered)

5a- air

gaseous substance whose weight affects AP. weighs more at earths surface

5a- air pressure

force exerted by gases pushing on an object. greatest near earths surface

5a- temperature

measure of energy of molecular motion. when airs heated, molecular activity increases, temp rises.

5a- warm air is _____ dense than cold air and exerts ____ pressure

less dense, less pressure

5a- moist air is _______ than dry air

lighter

5a- increased activity=

=increased spacing between molecules=reduced density of molecules=reduced AP

5a- water vapor increases=

=density decreases=pressure decreases

5a- molecular weight

water vapor (18.02)

nitrogen (28.02)

oxygen (32)

carbon dioxide (44.01)

5a- cold, dry air...

is dense and sinks. heavy molecules are closer together. AP increases

5a- hot, humid air...

is light and rises, light molecules are farther apart. AP decreases

5a- cycle of how air moves

cold, heavy air sinks --> moves toward warm, light air --> warm, light air rises --> produces wind

5a- convection

circulatory motion of descending cool air and ascending warm air

5a- convectional wind system

when surface-heated warm air rises and is replaced by cool air from above

5a- barometer

instrument that measures atmospheric air pressure

5a- isobar

line that connects points of equal barometric pressure

5a- short and long distances between H and L zones...

short distances = great difference in AP, faster, more violent winds

long distances = little difference in AP, slower, gentler winds

5b- equatorial low

(warm/wet), zone of low pressure near equator, warm air rises and moves towards poles.

5b- subtropical high

(hot/dry), warm air from equatorial low rises, cools, becomes dense, and falls. surface zones of high AP

5b- polar high

(cold/dry), high pressure area, descending air at poles 90 deg N & S of equator.

5b- subpolar low

(cool/wet), convergence of polar easterlies and westerlies. ascending air cools over ocean. Low pressure rising connects polar high to subpolar low

5b- polar easterlies

wind coming from poles.

N pole = winds from NE

S pole = winds from SE

5b- westerlies

mid-latitudes (30-60 degrees. N/S)

N hemi- winds from SW (most of U.S.)

S hemi- winds from NW

5b- trade winds

winds converging at equatorial low (most consistent winds on earth)

N hemi- NE trade wind

S hemi- SE trade wind

5b- intertropical convergence zone

low pressure near equator. warm, moise air rises, heavy rain= tropical biomes.

6a- hydrology

science of water and its global circulation, distribution, properties, w/ an emphasis on water at and below earths surface.

6a- distribution of earth's 71% water

majority (97%) is in oceans. only 3% is fresh.

of that 3%, 69.6% is in ice, 30.1% groundwater, 0.3% is surface water

6a- hydrologic cycle

water moves between reservoirs. atmosphere, surface, subsurface

6a- quick vs slow water cycles

quick- days to months, atmospheric and surface water

slow- years and years, oceans, groundwater, glaciers

6a- evaporation, transpiration, evapotranspiration (atmosphere component)

evaporation- water from hydrosphere to atmosphere. liquid to gas. 86% occurs over oceans

transpiration- water from biosphere to atmosphere. water vapor out of plants pores

evapotranspiration- combined effects of evaporation and transpiration from earths land surfaces.

6a- precipitation (surface component)

water from atmosphere to other earths spheres. gas to liquid.

6a- infiltration, percolation (subsurface component)

infiltration- water from earths surface to subsurface

percolation- surface water becomes groundwater when permeating soil or rock thru vertical movement downward

6b- runoff

water falls from sky, or melts from snow or glacier, flows over land surface, converges in low-lying areas, forms streams. streams merge into rivers, eventually reaching lake or ocean

6b- watershed

area of land, contributes water to particular water body. rain falls, runs off surface, flows downhill, until it finds surface water body

6b- what is the 4th largest watershed on earth

Mississippi River watershed

6b- aquifers

porous sponge-like formations of rock, clay, and sand-saturated w/ water.

6b- water table

top of that saturated layer

6b- recharge zone

any area where water can infiltrate thru earths surface and reach an aquifer

6b- springs

location below water table where water can escape to surface

6c- freshwater use increases with..

..demands of growing population

6c- majority of freshwater is used for...

agriculture (70%) ((industry 20%, residential use 10%))

6c- High Plains Aquifer

largest aquifer in the U.S. water is withdrawn much faster from this aquifer than it can be recharged

6c- surface water use-withdrawal has led to...

...many rivers running dry before reaching the sea

6c- which river serves 40 million ppl and 80% is used for agriculture

colorado river

6c- solutions to fresh water depletion:

increase supply or reduce demand

6c- desalination

removal of salt from ocean & brackish water to produce drinking water, or reduced-salt water

6c- reverse osmosis

pressure-filtering water thru tiny membranes w/ tiny pores that trap salt

6c- trade-off

expensive, uses lots of energy, generates brine (concentrated salty waste)

6c- reducing water demand at home and in agriculture:

agriculture:

- matching crops to climate-eliminating water-extensive

crops from arid regions

- switch to drip irrigation

at home:

- installing low-flow faucets, sinks, showerheads, etc.

- grey water reuse (water captured from washing and bathing, reused)

- rainwater harvesting

- xeriscaping (growing climate-appropriate plants in yards, reduces need for irrigation)

7a- weather vs. climate

weather- short-term, localized

climate- long-term atmospheric trends, average temps/precipitations/etc

7a- meterology

scientific study of atmosphere

7a- climatology

study of climate and climate variability over space & time

7a- climate change science

interdisciplinary study of causes and consquences if changing climate

7a- direct vs indirect measurements

direct- real-time sampling and observations of atmospheric air

indirect- environmental records such as tree rings, fossil pollen, ice cores, ocean and lake sediments

7a- proxy records

preserved physical characteristics of past environments that stand in for direct measurements

7a- paleoclimateology

study of earths past climates

hothouse climates = warmer

icehouse climates = colder

7a- evidence of climate change in past, present, and future

past- proxy indications of ice core data, sediments, coral reefs, ancient pollen, tree rings

present- weather station data, sensing data, modeling using general circulation models

future- predictions using general circulation models

7b- oxygen isotope analysis

measuring the ratio of stable oxygen isotopes in light oxygen-16 and heavy oxygen-18 in natural materials to reconstruct past climates. (ocean sediments, ice cores)

7b- how long are the records of ocean sediments and ice cores

ocean sediments- 70 million years (longest record)

ice cores- 800,000 years

7b- oxygen-16 vs. oxygen-18

oxygen-16: "light" oxygen, most common in nature, makes up 99.76% of all oxygen atoms. evaporates easily

oxygen-18: "heavy" oxygen, abt 0.20% of oxygen atoms. condenses easily.

-both occur in water molecules

7b- ratio of heavy to light oxygen isotopes in water...

varies with temperature

7b- during colder/glacial periods

"light" oxygen / 16O concentrated in snow/ice in polar regions, "heavy" oxygen / 18O concentrated in oceans

7b- during warmer/interglacial periods

snow/ice melts, returns 16O to oceans. 18O in oceans becomes less concentrated

7b- higher ratio of 18O/16O indicates in ocean sediments..

colder climate

7b- lower ratio of 18O/16O indicates in ocean sediments..

warmer climate

7b- foraminferal/forams (ocean sediment cores)

oxygen isotopes found in shells of marine microorganisms.

in variety of environments from equator to poles.

shells accumulate on ocean bottoms, build up layers of sediment, cores are extracted and used for analyzing oxygen isotope ratios

7b- ice cores

largest accumulations of glacial ice in Greenland and Antarctica

ice layers are "dated":

darker bands = winter snowfall

lighter bands = summer snowfall

air bubbles in ice contain past air samples. opposite isotope record compared to oceans

7b- higher ratio of 18O/16O indicates in ice cores..

warmer climate (16O returned to oceans)

7b- lower ratio of 18O/16O indicates in ice cores..

colder climate (more 16O locked in ice)

7c- Milankovitch cycle

long-term shifts in climate over thousands of years. consistent changes over time in shape of earths orbit, tilt of earths axis, and wobble of earths rotation

7c- earth's revolution

path changes from circular to oval (elliptical) over time

7c- perihelion vs. aphelion

perihelion - closest to sun (jan 3rd) 91.5 mill miles

apherlion - furthest from sun (july 4th) 94.5 mill miles

7c- eccentricity and its impact

shape of earths orbit around sun, 100,000 yr cycle, from nearly perfect circle to slightly elliptical.

imoact = changes length of seasons.

more elliptical = longer winter in S. hemisphere, distance decreases, length of seasons evens out

7c- earths axis

imaginary line between north and south poles. currently tilted 23.5 degrees.

7c- obliquity and its impact

angle of tilt of axis. 41,000 yr cycle, from 22.1 deg to 24.5 deg.

impact = changes in insolation at higher latitudes

7c- earths rotation on its axis, precession and its impact

full rotation = 24 hrs

precession - how much earth wobbles around axis while spinning, 26,000 yr cycle

impact = changes orientation of hemispheres and landmasses to sun

example: N hemi summer, now = aphelion, 13k yrs = perhelion

7c- climate feedbacks

processes that amplify/reduce climatic trends toward either warming or cooling (ice-albedo, water-vapor, permafrost-carbon)

7c- ice-albedo feedback

temp increases --> melting increases --> surface warming increases (via reduced albedo) --> melting increases --> (positive feedback loop continues)

7c- water-vapor feedback

increased evaporation --> more h2o in atmosphere --> increased greenhouse effect --> increased warming.

water vapor is the most abundant greenhouse gas. as temperature rises, evaporation increases

7c- warmer air holds..

more water vapor than colder air

7c- permafrost-carbon feedback

melting of permafrost--> increased release of CO2 and CH4 to atmosphere, increased greenhouse effect--> increased warming

7d- observable (direct) evidence of recent climate change

- record-breaking global avg. temps for air, land surfaces, lakes, and oceans

- ice losses from mountain glaciers

- increasing intensity of precipitation events

- changing distributions of plants and animals

- rising global sea level

7d- what causes present climate change

fluctuations in concentration of GH gases correlate with fluctuations in earths average surface temp

7d- higher levels of GH gases generally correlate with...

warmer interglacials

7d- lower levels of GH gases generally correlate with...

colder glacials

7d- which american geologist for shell oil company warned us about climate change in 1962

M. King Hubbard, when he released the Energy Resources Report

7d- keeling curve

direct measurements of atmospheric CO2

7d- red zig-zag line and black line meaning in graphs

red zig-zag = seasonal averages

black line = annual average

7d- what causes seasonal shifts in CO2 each year (red zig-zag line)

photosynthetic activity in northern hemisphere

7d- primary anthropogenic sources of atmospheric CO2

-fossil fuel combustion

-biomass burning

-removal of forests

-industrial agriculture

7d- CO2 highs and CO2 lows

CO2 highs- high volcanic activity, increased GH effect, warmer temps

CO2 lows- plant growth explosion, decreased GH effect, cooler temps

7d- general circulation models

used to assess past climatic trends & forecast future climate