1. Coastal Oceanography Outline Global coastal ocean Dynamics Western boundary current systems Eastern boundary current systems Polar ocean boundaries Semi-enclosed seas and islands

2. What is the coastal ocean? The coastal ocean is the portion of the global ocean where physical, biological and biogeochemical processes are directly affected by land It is either defined as the part of the global ocean covering the continental shelf or the continental margin

3. Importance Represent 20% of Earth surface 50% of human population lives in coastal regions By 2025 projected that 75% of human population will live in coastal areas Support most fisheries, sink/source for CO2, sites of water formation, sites for resource extraction

4. Coastal Ocean Shelf seas – depths of 10s to 100s meters, extend outwards from coast to shelf break (10s to 100s km) Beyond shelf break have slope sea – extend outwards to deep ocean depths Extend along coastlines from poles across equator – affected by the full range of climate variability Experience remote and local forcings – mixture of dynamics – makes study challenging

6. Salinity increases towards shelf break Winter – vertically homogeneous Summer – two layer stratified system Coastal ocean structure off NJ

7. Across-shelf salt transport Middle Atlantic Bight Offshore increase in salinity – freshening from river discharge inshore Density barrier (front) at shelf break separates fresher shelf water from salty ocean water Salt mixes across front

8. Dynamics Connectivity to adjacent deep ocean Tides – mixing and hydrographic structure – Gulf of Maine, Amazon and Patagonian shelves Fresh water – Land runoff, advection by ocean currents, sea ice, excess precipitation (tropics, monsoons) – Affects stratification, buoyancy forced baroclinic flows Wind stress Surface heat fluxes – Water formation regions, seasonal heating/cooling Sea ice – Air-sea interactions, convective mixing, stratification Coriolis effects, Ekman flow, coastal upwelling

9. River Plumes Discharge of freshwater onto shelf turns right due to Coriolis and mixes Hudson River Plume

10. St. Laurence River adds freshwater in Canada Coriolis turns freshwater southward Other rivers add freshwater – turn southward Buoyancy drives southward flow on Middle Atlantic Bight shelf Effect of Freshwater

11. Secondary Wind Effects – Upwelling winds Push shelf flow offshore

12. Columbia River – West coast of US Produces a large plume Direction of turning on shelf is variable

13. Flow Instability Ocean flow is sufficiently energetic that it becomes unstable West coast upwelling create eddies

14. Cold Pool – result of winter deep mixing Cold water is isolated by summer stratification Deep shelf water remains cool throughout summer Provides habitat for cold adapted infauna – clams

15. Change in cold pool

16. Brink and Robinson, The Sea, 2005 Coastal Ocean – global distribution

17. Panregional Categories Western boundary current systems Eastern boundary current systems Polar ocean boundaries Semi-enclosed seas and islands

18. Western Ocean Boundary Shelves Influenced by western boundary currents Advective dominance Shelf impacted by eddies and rings Intrusions of deep ocean water masses

19. Warm core rings Form from instabilities in flow Occur where GS separates from shelf Mechanism for flushing shelf waters

20. South Atlantic Bight Gulf Stream at the outer shelf edge Gulf Stream Filaments and Eddies

21. Gulf Stream puts water at shelf edge Upwelling moves water onto the shelf GS Front

22. Eastern Ocean Boundary Shelves Influenced by eastern boundary currents Upwelling regions Wind-driven

23. Eastern Boundary Current Upwelling

25. California Current Filaments and Jets

26. Stratification retention frontal exchanges Sea ice Ice shelves Modify dynamics Polar Shelves - Western Antarctic Peninsula continental shelf

27. ACC CDW

31. Antarctic Circumpolar Current

32. Ross Sea continental shelf

33. Past 50 years Projected next century Smith et al. (2012, Oceanogr.)

34. Arctic Rivers

36. Next Class Interdisciplinary physical oceanography applications, international global environmental change research