midterm #1 results posted early next week see blackboard
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Midterm #1 results posted early next week see BlackBoard. Answer Keys for both White and Blue exams will be provided on course website Scantrons will be returned in labs next week. Physical and Chemical Structure of the Ocean. Why are the oceans blue? How is sound transmitted in the ocean? - PowerPoint PPT PresentationTRANSCRIPT
Midterm #1 resultsposted early next week
see BlackBoard
Midterm #1 resultsposted early next week
see BlackBoard
Answer Keys for both White and Blue exams will be provided on course website
Scantrons will be returned in labs next week
Answer Keys for both White and Blue exams will be provided on course website
Scantrons will be returned in labs next week
Physical and Chemical Structure of the OceanPhysical and Chemical Structure of the Ocean
Why are the oceans blue?How is sound transmitted in the ocean?
Why is the ocean “layered” in many locations?
How do you keep your beer cool in the tropics?
Why are the oceans blue?How is sound transmitted in the ocean?
Why is the ocean “layered” in many locations?
How do you keep your beer cool in the tropics?
Light Absorption in WaterLight Absorption in Water
Intensity decreases rapidly with depthBlue and green penetrate deepest, giving the ocean its color
Why do objects lose their color with depth?
Why do objects lose their color with depth?
The colors other than blue (and green) are absorbed by the water molecules in the first few meters -- only blue (and green) are reflected
The colors other than blue (and green) are absorbed by the water molecules in the first few meters -- only blue (and green) are reflected
Sound in Sea WaterSound in Sea WaterSound is transmitted better in water Sound is transmitted better in water than it is in airthan it is in airSound velocity in the ocean is about Sound velocity in the ocean is about 1500 m/s, or about 4 times its speed in 1500 m/s, or about 4 times its speed in airairSound velocity increases with pressure Sound velocity increases with pressure and temperatureand temperature
SOFAR Sound ChannelSOFAR Sound Channel
Sound is focused into the SOFAR channel because it is a low velocity region
Sound is transmitted best through this channel -- good for whales and submarines(e.g., “Hunt for Red October”)
Sound is focused into the SOFAR channel because it is a low velocity region
Sound is transmitted best through this channel -- good for whales and submarines(e.g., “Hunt for Red October”)
Heard Island ExperimentHeard Island ExperimentGlobal Warming -- faster velocity??Global Warming -- faster velocity??
Go to Sounds
Go to Sounds
Ocean TemperatureSolar HeatingOcean TemperatureSolar Heating
Uneven heating of Earth’s surface
Release of heat asinfrared radiation
Requires flow ofheat by oceans andatmosphere
Surface circulation
Uneven heating of Earth’s surface
Release of heat asinfrared radiation
Requires flow ofheat by oceans andatmosphere
Surface circulation
Global Heat BudgetGlobal Heat Budgetheat at the Earth's
surface (342 W/m2) is supplied by absorption of ‘short-wave’ solar radiation from the sun.
heat lost from Earth is through long-wave radiation back to space.
heat at the Earth's surface (342 W/m2) is supplied by absorption of ‘short-wave’ solar radiation from the sun.
heat lost from Earth is through long-wave radiation back to space.
The Greenhouse EffectThe Greenhouse Effect
The Atmosphere is transparent to sunlight (ultraviolet [UV] and visible)
Clouds absorb or reflect about halfSunlight heats the Earth’s surface,
which then radiates energy as longer wavelength energy (infrared)
This energy is trapped by the atmospheric gases (CO2, H2O, CH4)
The Atmosphere is transparent to sunlight (ultraviolet [UV] and visible)
Clouds absorb or reflect about halfSunlight heats the Earth’s surface,
which then radiates energy as longer wavelength energy (infrared)
This energy is trapped by the atmospheric gases (CO2, H2O, CH4)
Special Properties of Water
Special Properties of Water
RECALL:Melting and boiling points are very highHighest heat capacity of common liquidsHigh heat of fusion and vaporization
RECALL:Melting and boiling points are very highHighest heat capacity of common liquidsHigh heat of fusion and vaporization
Sea Surface Temperaturesonly 0°-30°C world-wide
Sea Surface Temperaturesonly 0°-30°C world-wide
Land: 50°C to -50°C
Local Annual Heat BudgetsLocal Annual Heat Budgets
Amount of solar energy captured at one location on the Earth varies with season
Amount of solar energy captured at one location on the Earth varies with season
Local Annual Heat BudgetsLocal Annual Heat Budgets
Amount of solar energy captured at one location on the Earth varies with season
Amount of solar energy captured at one location on the Earth varies with season
Where we liveWhere we live
Temperature (vertical profile)Temperature (vertical profile)
Seasonalchanges in temperature profile
Temperature (vertical profile)Temperature (vertical profile)
Cool drinks go here
Thermocline
Temperatures with DepthTemperatures with Depth
Thermocline -- sharp temperature change
Thermocline -- sharp temperature change
Evaporation - PrecipitationEvaporation - Precipitation
Over the oceans, evaporation exceeds precipitation
The balance is restored by rain over the continents, returning water via rivers
Over the oceans, evaporation exceeds precipitation
The balance is restored by rain over the continents, returning water via rivers
Evaporation vs Precipitation
Evaporation vs Precipitation
Climate BeltsClimate Belts
Ocean Surface SalinityOcean Surface Salinity
Salinity VariationsSalinity Variations
Salinity VariationsSalinity Variations
Surface salinity follows evaporation-precipitation pattern
Atlantic Ocean is generally more salty than Pacific Ocean, in spite of river input -- why??
Surface salinity follows evaporation-precipitation pattern
Atlantic Ocean is generally more salty than Pacific Ocean, in spite of river input -- why??
Isthmus of PanamaIsthmus of Panama
Net transfer offresh waterfrom Atlanticto Pacific
Net transfer offresh waterfrom Atlanticto Pacific
Salinity of Rivers and Ocean Water
Can’t just concentrate river water to get seawater
How do we explain this observation?
Rivers
Ocean
Concept of Residence Time
Each element removed from ocean in different ways
And at different rates
e.g. Cl- vs. SiO2
Residence Time
Flux has units of mass per unit time
Reservoir has units of mass
R/F has units of time
Density of Sea Water(Where does Oregon’s seawater
plot?)
Density of Sea Water(Where does Oregon’s seawater
plot?)
Density of Sea Water(Where does Oregon’s seawater
plot?)
Density of Sea Water(Where does Oregon’s seawater
plot?)
Bottom Water
Oregon’s ocean
Density Rules!Density Rules!
Where does the Ocean’s Deepest Water Come
From?
Where does the Ocean’s Deepest Water Come
From?The densest seawater is COLD and
SALTYThis is formed at high latitudes in the
North and South Atlantic: North Atlantic Deep Water (NADW) Antarctic Bottom Water (AABW)
Could dense seawater form in the tropics?
(evaporation!)
The densest seawater is COLD and SALTY
This is formed at high latitudes in the North and South Atlantic: North Atlantic Deep Water (NADW) Antarctic Bottom Water (AABW)
Could dense seawater form in the tropics?
(evaporation!)
Dissolved Gases in the OceanDissolved Gases in the Ocean
Important Gases in the OceanImportant Gases in the Ocean
Oxygen -- Respiration, Decomposition
CO2 -- Photosynthesis, CaCO3
Nitrogen -- Nutrient for growth (NO3)Methane -- a product of
decomposition
Oxygen -- Respiration, Decomposition
CO2 -- Photosynthesis, CaCO3
Nitrogen -- Nutrient for growth (NO3)Methane -- a product of
decomposition
Photosynthesis and Respiration
Photosynthesis and Respiration
Biology interacts with the ChemistryBiology interacts with the Chemistry
Dissolved OxygenDissolved Oxygen
Biochemical RecyclingBiochemical Recycling
Summary: Biochemical Cycles
Summary: Biochemical Cycles
Elements enter oceans through riversGases enter oceans thru air-sea boundaryBiology alters distribution of elements
(“nutrients”) and gasesOcean circulates nutrients to surface, but
only in a few places (called “upwelling”)Interaction of physics, chemistry and
biology => geological record (sediments)
Elements enter oceans through riversGases enter oceans thru air-sea boundaryBiology alters distribution of elements
(“nutrients”) and gasesOcean circulates nutrients to surface, but
only in a few places (called “upwelling”)Interaction of physics, chemistry and
biology => geological record (sediments)