Oceanography Important Concepts!

Hadley Cell Circulation

• warm air towards poles

• cold air towards equators

ferrel cell circulation

• warm air towards equator

• cold air towards poles

polar cell circulation

• warm air towards poles

• cold air towards equator

warm air

• air rises

• low pressure

cold air

• air sinks

• high pressure

air circulation around low pressure in NORTHERN

CCW

air circulation around high pressure in NORTHERN

CW

ekman transport in NORTHERN

to the right

subtropical gyre spin direction in NORTHERN

CW & deep thermocline

subtropical gyre spin direction in SOUTHERN

CCW & deep thermocline

subpolar gyre spin direction

CCW & shallow thermocline

NADW

• high latitudes in the North Atlantic

• salty sea surface water cools and sinks, making dense water (so salty that it doesn’t reach its freezing point before cooling)

• SECOND DENSEST

AABW

• southern ocean around antarctica

• surface water cooling/sinking AND the surface water freezing to form sea ice, leaving behind brine that sinks

• DENSEST

AAIW

• southern ocean around antarctica

• ekman transport (dense surface water gets pushed equator ward, until it gets pushed under a less dense surface water)

• MIDDLE DENSEST

NPIW

• North Pacific where the subtropical and sub polar gyres meet

• cabelling of two surface waters

• SECOND FRESHEST

spring tide

• full & new moon

• lunar bulges LINE UP with solar bulges, making biggest tidal range

neap tide

• first & third quarter moons

• lunar bulges are PERPENDICULAR to solar bulges, making smallest tidal range

perigee

when the moon is closest to the earth and the lunar tidal range is the largest

apogee

when the moon is furthest from the earth and the lunar tidal range is the smallest

perihelion

when the earth is closest to the sun (in January) and the solar tidal range is the largest

wave frequency

1/wave period (1/T)

shallow water wave

the water base is less than 1/20 of a wavelength

cause of a <5 min wave

wind

cause of a 5min-12hour wave

catastrophes (earthquakes, landslides, etc.)

cause of 12-24hour wave

sun and moon

factors that determine wave energy

1. wind speed

2. duration

3. fetch (the size of the storm from beginning to end, the max distance across which the wind is blowing to generate waves w/out obstruction)

Summer beach profile

• low wave energy

• wash dominates

• sediment is transported onto shore

winter beach profile

• high wave energy

• backwash dominates

• sediment is net transported OFF shore

as wave approaches coast…

• deep water wave becomes shallow water wave

• wavelength shortens

• wave height increases

pelagic zones

defined by depth

1. epipelagic

2. mesopelagic

3. bathypelagic

4. abyssopelagic

5. hadal

photic zones

defined by light

1. euphoric (1/2 of epipelagic)

2. disphotic (1/2 of epipelagic & mesopelagic)

3. aphonic (bathypelagic, abyssopelagic, hadal)

macronutrients

OFTEN LIMITING

• nitrogen & phosphorus

micronutrients

SOMETIMES LIMITING

• sodium chloride, iron, etc.