Question | Answer |
plane of ecliptic | line that connects all points of earth's orbit around sun |
seasons caused by | tilt of earths axis |
vernal equinox | march 21; spring; sun directly over equator; equal length of day & night; AKA spring equinox in NH |
summer solstice | june 21; sun is at most northerly position directly overhead of tropic of cancer; sun appears to pause (longer day) before beginning its next six month cycle |
tropic of cancer | 23.5 N |
autumnal equinox | september 23; sun is directly over equator again |
winter solstice | december 22; sun directly overhead of tropic of capricorn; |
suns declination | angular distance from equator (either 23.5N or 23.5S = tropics) |
tropics | receive more annual sunlight than poles |
albedo | percentage of radiation that is reflected back to space depending on the type of material----sea ice covered by snow has high albedo while soil, rock, vegetation, etc. does not |
avg earth surface albedo | 30% |
ocean reflects more radiation at | high latitudes |
earths atmo | N is 78% & O is 21% |
troposphere | lowermost portion of atmo; 12km/7mi; where weather is formed; lower T as altitude rises |
warm air | less dense bc heat makes molecules expand so rises |
cold air | more dense so sinks |
convection cell | warm air rises; cold air sinks |
warm air can hold | more water vapor than cold air bc its molecules are moving faster & can interact w the water vapor |
addition of water vapor | decreases the density of air |
water vapor has | lower density than air; humid air is LESS DENSE than dry air |
moving air | wind = ALWAYS FROM HIGH P TO LOW P |
NH coriolis effect | water drains CCW |
SH coriolis effect | water drains CW |
| |
coriolis effect | changes path of moving object |
coriolis effect dir in NH | right (perspective) |
coriolis effect dir in SH | left (perspective) |
coriolis is an effect of | earth rotation towards E----the difference in earths rotation SPEED at different latitudes |
earths rotational speed faster | closest to equator |
coriolis effect max | poles |
coriolis effect nonexistant | equator |
hadley cell | cold & warm air circulation between 0-30N & 0-30S |
ferrel cell | cold & warm air circulation betw. 30N-60N & 30S-60S |
polar cell | cold & warm air circulation above 60N-90N and above 60S-90S |
subtropical highs | descending cold air; areas of high pressure (dry & clear skies) |
polar highs | descending cold air; areas of high pressure (dry & clear skies) |
equatorial low | rising warm air; areas of low pressure (cloudy & rainy bc warm air cools and can't hold on to water vapor) |
subpolar low | rising warm air; areas of low pressure (cloudy & rainy bc warm air cools and can't hold on to water vapor) |
trade winds | air blown from subtropical highs to equatorial lows |
NE trade winds | NH so blow to the right |
SE trade winds | SH so blow to the left |
doldrums | boundary betw. the two trade winds at equator ------intertropical convergence zone (calm waters) |
horse latitudes | boundaries betw. trade winds and prevailing westerlies (light winds + dry and fair) |
polar front | boundaries betw. prevailing westerlies and polar regions (cloudy and rainy) |
monsoon winds | Asian seasonal shifts in atmospheric pressure (winter--high; summer---low) |
equatorial | 0-5 degrees; doldrums boundary; low P; light winds; cloudy & rainy; hurricanes |
5-30 degrees | trade winds wind belt; strong steady winds from E (NE & SE) |
30 degrees | horse latitudes boundaries; high P; light winds; dry & clear; major deserts |
30-60 degrees | prevailing westerlies wind belt; from W; brings storm that influence U.S weather |
60 | polar front boundaries; low P; variable winds; stormy & cloudy yearound |
60-90 | polar easterlies wind belt; cold dry winds from E |
poles | 90 degrees; polar high P boundary; variable winds; clear, dry, cold, desert regions, minimal rain |
coriolis force greatest at | the poles |
coriolis force almost non existent at | the equator |
why lots of deserts at 30S and 30N latitudes? | bc subtropical dry air |
as you increase in elevation | atmospheric pressure decreases |
cool dense air | sinks, high surface pressure |
warm moist air | rises, low surface pressure |
coriolis effect moves path of moving object in the NH towards | the R |
coriolis effect moves path of moving object in the SH towards | the L |
earth rotates towards the | east |
there are diff _____ at diff ________ bc of earths rotation | speeds ; latitudes (faster at equator & slower at poles) |
winds---air always moves from | high pressure to low pressure |
cyclonic flow in low pressure NH | CCW |
cyclonic flow in low pressure SH | CW |
anticyclonic flow in high pressure NH | CW |
anticyclonic flow in high pressure SH | CCW |
anticyclonic | high pressure |
cyclonic | low pressure |
low pressure | rising air (warm) |
high pressure | sinking air (cold) |
tropical cyclones, hurricanes, typhoons | large rotating makes of low pressure; classified by max. speed of wind sustained |
conditions needed for a hurricane | 25C/77F (warm water needed for water vapor to atmo via evaporation); warm moist air to supply vast amounts of latent heat; coriolis effect gives rotation to storm |
storm surge | increase in shoreline sea level |
open ocean climate is | sort of // to latitude lines (warmer at center and colder at sides) w exception of currents [england at high latitude but not as cold] |
sea ice | forms directly from seawater; needle-like crystals become slush--->slush becomes pancake ice--->pancake ices form ice floes |
iceberg formation | break off from glaciers |
ocean currents | masses of water that flow from one place to another |
surface currents | wind driven; primarily horizontal direction; only 10% of ocean water; occur above pycnocline; slower than corresponding wind bc friction of wind & ocean; generally follow wind belts pattern |
deep currents | driven by density differences caused by diff salinity & temperature (low T & high salinity = high density); vertical & horizontal motions |
surface currents: gyres | large circular loops of moving water driven by major wind belts |
surface currents: subgyres | centered around 30 degree latitude; bounded by equatorial current; western, northern, southern, and eastern boundary currents |
surface currents: ekman spiral | balance betw. friction and coriolis effect; direction & flow of surface waters at diff depths; direction of spiral is PERPENDICULAR to wind |
surface currents: ekman transport | avg. movement of surface waters, 90 degrees to R in NH; 90 degrees to L in SH |
surface currents: top of hill water displaced toward | west bc of earths rotation |
surface currents: western boundary currents get | intensified in both hemispheres (bc coriolis effect)
1. faster
2. narrower
3. warmer
4. deeper |
surface currents: easter boundary currents are | the opposite of western boundary currents
1. cold
2. shallow
3. slow
4. wide |
upwelling | vertical movement of cold, nutrient-rich water to the surface (high productivity of algae) |
downwelling | vertical movement of surface water downward in the water column |
diverging surface water | upwelling (equator) |
equatorial upwelling | divergence of currents at equator generates upwelling and high productivity |
converging surface water | downwelling of surface water; surface waters move towards each other and pile up downward; low productivity |
coastal upwelling | ekman transport moves surface water offshore & replaces w cool nutrient-rich water (W. US San Francisco cool temperatures) |
coastal downwelling | ekman transport moves surface water towards shore; water piles up moves downward in water column |
halocline | difference in salinity as depth increases |
pycnocline | difference in density as depth increases |
other causes of upwelling | 1. offshore winds
2. seafloor obstructions
3. coastal geometry change
4. lack of pycnocline (high lat. oceans---cold) |
antarctic circulation: antarctic circumpolar curent | AKA WEST WIND DRIFT; driven by prevailing westerly winds |
antarctic circulation: easterly wind drift | driven by polar easterlies, creates surface diverging w opposite antarctic circumpolar current |
antarctic circulation: antarctic divergence | abundant marine life |
atlantic circulation: gulf stream | western boundary current that carries warm water from topics to high latitudes; responsible for mild temp in europe (england) |
walker circulation cell | cold higher pressure in E pacific (peru); SE winds; thermocline deeper in W side (australia) |
el niño | warm phase; disruption in walker circulation cell; downwelling; warm pool spreads more eastward to where cooler waters were; weaker trade winds |
la niña | cool phase; stronger upwelling in E; cooler than normal seawater; stronger trade winds |
deep-water masses | antarctic bottom water, north atlantic deep water, antarctic intermediate water; cold surface water sinks and moves equatorward |
how are waves generated | 1. wind |
air-ocean interference | ocean waves |
water-water interference | internal waves |
wave movement | energy in motion---waves transmit energy |
crest | high point of wave |
trough | low point of wave |
the deeper the water, the ______ the wave | faster |
capillary waves | ripples; wind generated on surface |
gravity waves | more E transferred to ocean, increasing wave E; wave height increases more than length; breaking waves |
factors affecting wind E | fetch, duration wind blows over on one direction, wind speed |
fetch | distance over which wind blows |
swell | free ocean wave generated by wind that gets transported to surf zone w/o losing much E |
shoaling water | water gradually getting shallower |
surf zone | where waves break near shore |
when steepness >1/7 | wave breaks |
as wave approaches shallower water | wavelength decreases, speed decreases, steepness increases, height increases |
waves rarely approach shore at | 90 degrees rather they're angled |
on shore, wave E is | unevenly distributed & less |
headlands | better for surfing; more wave E released bc waves CONVERGE |
bays | wave E diverges; E more dissipated vs headlands |
splash waves | ~tsunami caused by meteorite impact |
tides caused by | combination of each, moon, and sun gravity & motion |
zenith | greatest force of gravity; closest to moon |
nadir | lowest force of gravity; furthest from moon |
direction of attraction between earth and moon is | at an angle causing force to be slightly diff everywhere |
lunar day | 24 hr 50 min |
high tides are _________ apart | 12 hrs 25 min |
flood tide | water moves toward shore |
ebb tide | water moves away from shore |
tidal period | time between high tides |
tidal range | difference betw, high and low tides |
monthly tidal cycle | 29.5 days (time it takes moon to complete orbit around earth) |
syzygy | moon, earth, and sun aligned |
quadrature | moon in first or third quarter phase |
spring tides | new or full moon; tidal range greatest; syzygy |
neap tides | quarter moons; tidal range lowest; quadrature |
declination | angular distance of the moon or sun above or below earths equator |
perigee | tidal range greatest; moon closest to earth |
apogee | tidal range least; moon furthest from earth |
perigee and apogee cycle | 27.5 days |
perihelion | earth closest to sun; Winter in NH |
aphelion | earth furthest from sun; Summer in NH |
amphidromic point | no tidal range; crests & troughs of tides rotate around it |
cotidal lines | connects simultaneous high tide points |
tide wave rotates every | 12 hrs |
in theory, most areas should experience __ ___________ & __ ____________ | 2 high tides & 2 low tides of unequal heights during a lunar day ( but ocean basin diff in shape, size, and depth modify this) |
diurnal | 1 high & 1 low tide per day; common in inland seas (GULF OF MEXICO) |
semidiurnal | 2 high & 2 low tides; tidal range same |
mixed | 2 high & 2 low tides; tidal range different (MOST COMMON) |
high slack water | peak of each high tide w no current motion |
low slack water | peak of each low tide w no current motion |
coastline | boundary betw. coast and shore |
backshore | above high tide shoreline; only has water when theres a storm |
foreshore | exposed in low tide; submerged in hight tide |
nearshore | extends seaward from low tide shoreline; never exposed; waves touch bottom |
offshore | beyond low tide breakers; waves rarely touch bottom |
beach | above shoreline called recreational beach |
wave cut beach | flat wave-eroded surface |
berm | dry, gently sloping elevated beach margin at feet of dunes or cliffs |
beach face | wet sloping surface extending from berm to low tide shoreline (submerged) |
longshore bar | sand bars // to coast (not always present; break approaching waves) |
longshore trough | separates longshore bar from beach face |
sand forms from | sand & mud from rivers, local material, boulders from local cliffs, coral reef material (tropical) |
swash | water rushes up to beach |
backwash | water drains back to beach |
what determines if sand is eroded or deposited? | whether backwash or swash dominates |
light wave activity | swash soaks beach; wide well-dev. berm (pleasant) |
heavy wave activity | backwash; eroded sand accumulates in longshore bar |
summertime beach | milder storms; light wave activity; swash doms.; no longshore bars; wide sandy berm; deposited; steep beach |
wintertime beach | stormy weather; heavy wave activity; narrower beach; longshore bars present; backwash; eroded; flat beach |
longshore current | transports sand along beach in zigzag movement |
longshore drift | longshore current but occurs in surf zone |
tombolo | sand bar that connects an island to the mainland |
spit | lil piece of land stretching from mainland into lagoon but not completely enclosing to make a lagoon |
deltas | rivers deposit into oceans |
hard stabilization | structures built to decrease coastal erosion & interfere w sand movement (may actually increase wave erosion)
1. jetties
2. seawalls
3. groin & groin fields |
3 major alt. to hard stabilization | 1. construction restrictions near shorelines
2. beach (sand) replenishes
3. relocation of structures rather than protection |
sea level can change by | change in level of land or sea or both |
marine terraces | flat platforms backed by cliffs where wave-cut beach is exposed |
faster seafloor spreading = | rising sea level |
contracts | cooler water |
expands | warmer water |
eustatic sea level change | WORLDWIDE; faster seafloor spreading, formation or melting of glaciers, thermal expansion or contraction of water |
changing sea level | isostatic adjustment (unloading heavy load); tectonic movements (uplift or subsidence-----W coast is uplifting) |
sea breeze | sea to land---DAY |
land breeze | land to ocean---NIGHT |
% marine debris from land | 80% |
Standard lab bioassay: | concentration of pollutant that causes 50% mortality among test organisms |
oil spills are often from | transportation accidents |
petroleum | made of hydrocarbons, can biodegrade, has toxic components |
Bioremediation: | using bacteria and fungi to biodegrade oil |
about _____ hurricanes occur each year | 100 |
hurricanes are classified w ________ kmph | 120 |
wind shear | strong wind can ventilate heat away from dev. hurricane |
hurricanes raise | sea level temporarily |
proxigean tides | perigee + spring tides (unusually high tides) |
sand moves ______ to beach | perpendicular |