Oceans
Circulation: Movement of ocean water
Carbon Uptake: The ability of oceans to absorb carbon dioxide
Linking Structure, Circulation, and Carbon Uptake: How these elements interact
Required Reading: Huddart, D. and T. Scott, 2010. Earth Environments. Chap. 8
Page 4: Outline
Ocean Structure
Ocean depths and land elevations
Age of oceanic crust
Hypsography (study of elevation distribution)
Temperature and salinity changes with depth
Ocean Circulation
Surface and deep circulation
Density Controls
North-South density distribution
Surface salinity
Simplified circulation model: The Great Ocean Conveyor
Carbon Uptake: Overview of carbon uptake mechanisms.
Page 5: Ocean Structure
Continental Shelves: Shallow areas near coastlines
Deep Ocean Plains: Vast, flat ocean floor areas
Mid-Ocean Ridges: Underwater mountain ranges formed by tectonic activity.
Page 6: Age of Oceanic Crust
Mid-Ocean Ridges: Formation and significance in sea floor spreading
Page 7: Hypsography
Definition: Distribution of elevations on Earth's surface
Includes land and seafloor elevation description
Bimodal Distribution: Combination of land elevation and seafloor depth profiles
Page 8: Temperature and Salinity Changes with Depth
Graph Overview: Demonstrates the relationship between depth, temperature, and salinity
Notable points include thermocline and halocline depth transitions.
Page 9: Surface Circulation
Driving Forces: Factors influencing surface ocean circulation
Illustration: Expectations of surface circulation patterns discussed.
Page 10: Characteristics of Surface Circulation
Influenced by: Major atmospheric wind patterns
Wind contributes 3-5% speed to ocean currents up to 100m depth
Page 11: Ocean Circulation Reiteration
Surface Circulation: Summarized description from previous discussion.
Page 12: Heat Transfer and Global Circulation
Heat Transfer: Energy dynamics in ocean currents and climate interactions
Energy transfer measured in kilocalories per year
Page 13: Deep Circulation Drivers
Drivers of Deep Circulation: Assessment of water properties and weight
Page 14: Density Controls
Density Factors: Temperature, salinity, and pressure influence ocean density.
Changes in salinity and temperature directly affect density levels
Density Range: Oceans typically range from 1.020 g/cm³ to 1.030 g/cm³.
Page 15: Three Density Zones Overview
Surface Zone: Mixed layer with consistent temperature/salinity due to mixing.
Pycnocline Zone: Rapid density increase with depth; significant characteristics.
Deep Zone: Deepest layer; stable temperature and salinity.
Page 16: Surface Zone Details
Characteristics: Upper layer of the ocean, influenced by wind and light availability
Volume Contribution: Comprises about 2% of ocean volume
Page 17: Pycnocline Zone
Depth and Density: Rapid changes in temperature and salinity contribute to density shifts
Represents about 18% of ocean water volume
Page 18: Deep Zone
Summary: Characteristics include constant density, cold temperatures, and lack of light
Accounts for 80% of ocean water volume
Page 19: Density with Depth
Graph Tracking: Changes in temperature, salinity, and density with increasing depth illustrated
Page 20: North-South Density Distribution
Geographical Density Variations: Density differences influenced by latitude and specific regions
Page 21: Surface Salinity
Mean Annual Sea Surface Salinity: Variation dependent on latitude, summarized in a graphic
Page 22: Simplified Deep Circulation Model
Visual Representation: Expected positions and movements within the deep ocean structures
Page 23: Simplified Circulation Diagram
Thermocline Features: Notable ocean currents and their impact on nutrient distribution
Page 24: Deep Circulation Overview
Thermohaline Circulation: Description and photos illustrating densities influence on movement
Key role in climate support and distribution patterns
Page 25: The Ocean Conveyor
Global Circulation Context: Overview of various oceanic water masses and their dynamics
Page 26: Heat Transfers and Climate
Long-term Global Trends: Ocean temperature shifts since 1955 shown in comparative graphs.
Page 27: Observations on Warming
Regional Temperature Increases: Northern latitudes showing increased warming trends
Page 28: Carbon Uptake Dynamics
Annual Flux of CO2: Impact of ocean on global carbon absorption discussed
Page 29: Oceans as CO2 Sinks
Significance: Oceans actively moderate anthropogenic CO2 emissions
Deep water formation assists this process in specific regions
Page 30: Carbon Inventory Overview
Anthropogenic Carbon Inventory: Visual representation of inventory levels across latitudes
Highlighting notable changes over time from 1750 to 2005
Page 31: Biogeochemical Changes
Impact of CO2 on Ocean Chemistry: Effects on pH and potential impacts on marine life discussed
Page 32: Deep Water Aspects
Formation Importance: Key role in heat transport and CO2 storage
Sensitivity to environmental changes discussed
Page 33: The Great Ocean Conveyor
Potential Changes: Concerns regarding alterations in circulation patterns and density factors
Page 34: AMOC Discussion
Tipping Point Concerns: Evaluating the sensitivity of ocean currents to freshwater influx
Page 35: CESM Simulation Findings
Modeling Future Projections: Anticipated implications of freshwater flux on AMOC stability
Page 36: Biological Activity
Primary Productivity Metrics: Tracking nutrient availability and productivity across oceans
Page 37: Influences on Plant Productivity
Contributions: Overview of factors affecting primary productivity in ocean ecosystems
Page 38: Oceanic Nutrient Dynamics
Nutrient Uptake and Cycling: Mechanisms supporting phytoplankton and zooplankton growth rates
Page 39: Carbon Uptake Mechanisms
Pumps Overview: Biological and solubility pumps explained as CO2 sinks
Page 40: Summary of Key Conclusions
Ocean Characteristics: Summary of ocean depth, circulation, diversity, and climate implications
Next Topic Assessed: Climate Patterns.