Unit 2 - Buoyant Plumes Flashcards
Which processes are discussed in relation to shelf circulation?
The processes discussed include upwelling ecosystem impacts, internal waves, headland vortices, and interacting processes.
What effect does Earth’s rotation have on wind-driven currents?
Earth’s rotation introduces the Coriolis force, causing flow to turn right in the northern hemisphere and left in the southern hemisphere.
What is Ekman transport?
balance between wind stress and Coriolis force, leading to water movement across the shore.
How does local bathymetry affect coastal upwelling?
Changes in bathymetry can accelerate the coastal jet and enhance upwelling.
What is the significance of internal waves in coastal environments?
Internal waves can have large amplitudes, suspend sediment, and transport nutrients and energy across the shelf.
How do internal waves influence nutrient transport?
Internal waves control tilt of thermocline, affecting delivery of nutrient-rich waters to nearshore habitats.
What causes headland vortices?
steady oscillating flows past a point, leading to asymmetric vertical structures.
What are the key details that determine the fate of coastal river plumes?
The strength of the river flow, tidal currents, coastline geometry, density differences, ambient ocean currents, and wind stress.
What is a natural tracer that can visualize plumes?
Sediment is used as a natural tracer to visualize coastal river plumes.
What interaction example is mentioned in the text?
An interaction between a plume and internal waves, with a thermal plume moving east while internal waves move north.
How does coastal upwelling impact marine ecosystems?
Coastal upwelling increases productivity by bringing nutrient-rich waters to the surface.
What role do internal waves play in sediment transport?
Internal waves generate strong enough velocities to suspend and transport sediment along the shelf.
How does the thermocline tilt affect nutrient delivery?
upward-tilt brings cold nutrient-rich waters nearshore, while a downward tilt does not deliver nutrients to nearshore areas.
How do local winds contribute to variability in coastal upwelling?
Changes in local wind direction and speed, often influenced by local mountains, cause variability in coastal upwelling.
What is the spatial scale of internal waves along the shelf?
Internal waves have length scales of ~O(10s km) and horizontal scales of ~O(10s - 1 km).
What could disrupt understanding of headland vortices?
Observational challenges and the need for resolved spatial scales
Why is the coastal jet described as unstable?
The coastal jet forms meanders and can break like waves, leading to instability.
What does the variability in coastal upwelling indicate?
local conditions significantly influence effectiveness of upwelling processes.
How do nutrients from internal waves benefit kelp forests?
Nutrient-rich waters reaching kelp forests support their growth and health.
What does increased productivity in ecosystems correlate with?
nutrient availability due to upwelling and river plumes.
How do internal waves interact with the thermocline?
Internal waves cause tilting of thermocline, influencing availability of nutrients in nearshore habitats.
What is one effect of wind stress on coastal processes?
Wind stress affects strength of river plumes and their mixing with ambient waters.
What phenomenon is associated with the point of coastal headlands?
The formation of headland vortices, which mix and transport water across the shelf.
How do seasonal patterns relate to upwelling phenomena?
Upwelling can show variability through seasonal patterns influenced by wind conditions.
