Mea 100 exam 2 NCSU

Run-off

water flowing on the surface of the earth flows downhill to the lowest point

watershed

An ecosystem where all water runoff drains into a single body of water

stream properties

channel dimensions, gradient, discharge, sediment load

chanel dimensions

width and depth

gradient

slope

discharge

volume/time

sediment load

erosion, transport, deposition, and sediment grain size

Meanders

amplify the sinuosity, can form an ox bow lake

aquifer

permeable layer transporting groundwater

springs

occur whenever the water table reaches the surface typically near the base of steep slopes

artesian wells

occur when a break in a confined aquifer transports water to the land surface below the recharge elevation

overpumping

the cone of depression is a local decrease in the water table surrounding a well as a result of excessive pumping

Salt water intrusion

in coastal environments, the cone of depression lowers the freshwater table, which causes the intrusion of saltwater from below

Water quantity threats

too much or too little water

water quality threats

condition of water relative to the requirements of biological species

Dams

creates flood control, reservoirs for drinking water and irrigation, recreation, electricity generation. Also traps sediment, degrades river ecosystems and can fail catastrophically

Channelization

creates flood control and transportation. causes loss of wetlands, loss of biodiversity and disappearing deltas

overpumping of groundwater

the cone of depression is a local decrease in the water table surrounding a well as a result of excessive pumping

tragedy of the commons

individually rational economic decisions about shared resources can work against the interests of all

Why the ocean matters

food and resources, transportation, climate, recreation, and safety

ekman spiral

surface water flows 45° angle to the right of the wind

coriolis effect

due to the rotation of the earth, to the right in the northern hemisphere and to the left in the southern hemisphere

Upwelling

brings cold, nutrient rich water up from below

Deep ocean circulation

driven by density of water

Great ocean conveyor belt

deep and slow currents

atmosphere

the gaseous envelope that surrounds a celestial body

air

the invisible, odorless mixture of gases and suspended particles that surrounds earth

air composition

78% Nitrogen

21% Oxygen

1% Other Gases

1-4% Water vapor by Volume

Ozone

necessary to protect life on the surface from harmful ultraviolet radiation from the sun

Stromatolites

where the oxygen on earth came from

Pressure

force (gravity) per area

adiabatic lapse rate

the rate at which atmospheric temperature decreases with increasing altitude in conditions of thermal equilibrium

Atmospheric structure

thermosphere, mesosphere, stratosphere, troposphere

Auroras

in the thermosphere

coldest layer

in the mesophere

ozone

in the stratosphere

weather

in the troposphere

weather

the state of the atmosphere at a given time and place, determined by five variables

Air temperature decreases

when pressure decreases (PV = nRT)

temperature changes

due to seasonal changes, day to night change, when traveling north or south, or changing elevation

sea breeze

land heats up more rapidly than the seas, pressure gradient develops, air flows onto the land, creating a ________ breeze

land breeze

land cools off more rapidly than the sea, pressure gradient develops, air flows away from the land, creating a _________ breeze

pressure gradient

air always flows from high to low surface pressure

isobars

lines of equal pressure on a map

steeper pressure gradient

faster wind on a map

fronts

very large volume of air (covering thousands of miles) with similar temperature and humidity

Polar P

cold front

Tropical T

warm front

Marine m

moist weather

Continental c

dry weather

front

boundary between air masses

density lifting

warm, low-density air rises convectively

frontal lifting

two flowing air masses of different density meet, one forcing the other up

orographic lifting

flowing air is forced upwards due to terrain

convergence lifting

flowing air masses converge and are both forced upward

climate

weather patterns of a place over many years

differential heating

the amount of solar radiation at any given location on earth depends on the angle of sunlight and the hours of daylight

seasonal variation

summer: hemisphere tilted towards the sun

winter: hemisphere tilted away from the sun

thermal circulation

rising and sinking air due to variation in density with temperature

atmospheric circulation

3 thermal cells circulations between equator and pole, like a gear system