Extra Credit #3Extra Credit #3

May 4 (Monday), 7:30pmMay 4 (Monday), 7:30pmByrne LectureByrne LectureDr. Eddie Bernard, NOAADr. Eddie Bernard, NOAA“Tsunamis”“Tsunamis”Austin AuditoriumAustin AuditoriumLaSells Stewart centerLaSells Stewart center1-page reaction paper to your 1-page reaction paper to your TATA

Physical and Chemical Physical and Chemical Structure of the OceanStructure of the Ocean

Why are the oceans blue?Why are the oceans blue?

How do you keep your beer How do you keep your beer cool in the tropics?cool in the tropics?

Light Absorption in Light Absorption in WaterWater

Intensity Intensity decreases decreases rapidly with rapidly with depthdepthBlue and green Blue and green penetrate penetrate deepest, giving deepest, giving the ocean its the ocean its colorcolor

Why do objects lose Why do objects lose their color with their color with

depth?depth?

The colors other than blue The colors other than blue (and green) are absorbed by (and green) are absorbed by the water molecules in the the water molecules in the first few meters -- only blue first few meters -- only blue (and green) are reflected(and green) are reflected

Sound in Sea WaterSound in Sea WaterSound is transmitted better in Sound is transmitted better in water than it is in airwater than it is in airSound velocity in the ocean is Sound velocity in the ocean is about 1500 m/s, or about 4 times about 1500 m/s, or about 4 times its speed in airits speed in air

SOFAR Sound ChannelSOFAR Sound Channel

Sound is focused into the SOFAR Sound is focused into the SOFAR channel because it is a low velocity channel because it is a low velocity regionregion

Sound is transmitted best through Sound is transmitted best through this channel -- good for whales and this channel -- good for whales and submarines submarines

Heard Island Heard Island ExperimentExperiment

Global Warming -- faster velocity??Global Warming -- faster velocity??

Solar HeatingSolar Heating

Uneven heating of Uneven heating of Earth’s surfaceEarth’s surface

Release of heat asRelease of heat asinfrared radiationinfrared radiation

Requires flow ofRequires flow ofheat by oceans andheat by oceans andatmosphereatmosphere

Global Heat BudgetGlobal Heat Budget heatheat at the at the Earth's surface Earth's surface (342 W/m(342 W/m22) is ) is supplied by supplied by absorption of absorption of ‘short-wave’ ‘short-wave’ solar radiation solar radiation from the sun. from the sun.

heatheat lost from lost from Earth is through Earth is through long-wave long-wave radiation back to radiation back to space. space.

The Greenhouse EffectThe Greenhouse Effect The Atmosphere is transparent to The Atmosphere is transparent to sunlight (ultraviolet (UV) and sunlight (ultraviolet (UV) and visible) visible)

Clouds absorb or reflect about halfClouds absorb or reflect about half Sunlight heats the Earth’s surface, Sunlight heats the Earth’s surface, which then radiates energy as which then radiates energy as longer wavelength energy (Infrared)longer wavelength energy (Infrared)

This energy is trapped by the This energy is trapped by the atmospheric gases (COatmospheric gases (CO22, H, H22O, CHO, CH44))

Special Properties of Special Properties of WaterWater

RECALL:RECALL:Melting and boiling points are Melting and boiling points are very highvery highHighest heat capacity of common Highest heat capacity of common liquidsliquidsHigh heat of fusion and High heat of fusion and vaporizationvaporization

Sea Surface Sea Surface TemperaturesTemperatures

only 0°-30°C world-only 0°-30°C world-widewide

Land:Land: 50°C to - 50°C to -50°C50°C

Local Annual Heat Local Annual Heat BudgetsBudgets

Amount of solar energy captured at one location on the Earth varies with season

Temperature (vertical Temperature (vertical profile)profile)

Temperature (vertical Temperature (vertical profile)profile)

Beer goes here

Temperatures with Temperatures with DepthDepth

ThermoclineThermocline -- sharp temperature -- sharp temperature changechange

Evaporation - Evaporation - PrecipitationPrecipitation

Over the oceans, evaporation Over the oceans, evaporation exceeds precipitationexceeds precipitation

The balance is restored by The balance is restored by rain over the continents, rain over the continents, returning water via riversreturning water via rivers

Evaporation vs Evaporation vs PrecipitationPrecipitation

Climate BeltsClimate Belts

Ocean Surface Ocean Surface SalinitySalinity

Salinity VariationsSalinity Variations

Chemistry of River and Ocean Water

Can’t just Can’t just concentrate river concentrate river water to get water to get seawaterseawater

How do we explain How do we explain this observation?this observation?

Concept of Residence Time

Each element removed from ocean in different ways

And at different rates

e.g. Cl- vs. SiO2

Residence Time

F has units of mass per unit time

R has units of mass

R/F has units of time

Salinity VariationsSalinity Variations

Surface salinity follows Surface salinity follows evaporation-precipitation evaporation-precipitation patternpattern

Atlantic Ocean is generally more Atlantic Ocean is generally more salty than Pacific Ocean, in salty than Pacific Ocean, in spite of river input -- why??spite of river input -- why??

Isthmus of PanamaIsthmus of Panama

Net transfer ofNet transfer offresh waterfresh waterfrom Atlanticfrom Atlanticto Pacificto Pacific

Density of Sea WaterDensity of Sea Water(Where does Oregon’s seawater (Where does Oregon’s seawater

plot?)plot?)

Density of Sea WaterDensity of Sea Water(Where does Oregon’s seawater (Where does Oregon’s seawater

plot?)plot?)

Bottom Water

Oregon’s ocean

Density Rules!Density Rules!

Where does the Ocean’s Where does the Ocean’s Deepest Water Come Deepest Water Come

From?From?

The densest seawater is COLD and The densest seawater is COLD and SALTYSALTY

This is formed at high latitudes in This is formed at high latitudes in the North and South Atlantic:the North and South Atlantic: North Atlantic Deep Water ( North Atlantic Deep Water (NADWNADW)) Antarctic Bottom Water ( Antarctic Bottom Water (AABWAABW))

Could dense seawater form in the Could dense seawater form in the tropics?tropics?

(evaporation!)(evaporation!)

Dissolved Gases in the Dissolved Gases in the OceanOcean

Important Gases in the Important Gases in the OceanOcean

Oxygen -- Respiration, Oxygen -- Respiration, DecompositionDecomposition

COCO22 -- Photosynthesis, CaCO -- Photosynthesis, CaCO33

Nitrogen -- Nutrient for growthNitrogen -- Nutrient for growth Methane -- a product of Methane -- a product of decompositiondecomposition

Photosynthesis and Photosynthesis and RespirationRespiration

Biology interacts with the Biology interacts with the ChemistryChemistry

Dissolved OxygenDissolved Oxygen

Biochemical RecyclingBiochemical Recycling

Summary: Biochemical Summary: Biochemical CyclesCycles

Nutrients enter oceans through riversNutrients enter oceans through rivers Gases enter oceans thru air-sea boundaryGases enter oceans thru air-sea boundary Biology alters distribution of nutrients Biology alters distribution of nutrients and gasesand gases

Circulation returns nutrients to surfaceCirculation returns nutrients to surface Interaction of physics, chemistry and Interaction of physics, chemistry and biology => geological record (sediments)biology => geological record (sediments)