Unit 2 - Buoyant Plumes

Question 1

Which processes are discussed in relation to shelf circulation?

Answer 1

The processes discussed include upwelling ecosystem impacts, internal waves, headland vortices, and interacting processes.

Question 2

What effect does Earth’s rotation have on wind-driven currents?

Answer 2

Earth’s rotation introduces the Coriolis force, causing flow to turn right in the northern hemisphere and left in the southern hemisphere.

Question 3

What is Ekman transport?

Answer 3

balance between wind stress and Coriolis force, leading to water movement across the shore.

Question 4

How does local bathymetry affect coastal upwelling?

Answer 4

Changes in bathymetry can accelerate the coastal jet and enhance upwelling.

Question 5

What is the significance of internal waves in coastal environments?

Answer 5

Internal waves can have large amplitudes, suspend sediment, and transport nutrients and energy across the shelf.

Question 6

How do internal waves influence nutrient transport?

Answer 6

Internal waves control tilt of thermocline, affecting delivery of nutrient-rich waters to nearshore habitats.

Question 7

What causes headland vortices?

Answer 7

steady oscillating flows past a point, leading to asymmetric vertical structures.

Question 8

What are the key details that determine the fate of coastal river plumes?

Answer 8

The strength of the river flow, tidal currents, coastline geometry, density differences, ambient ocean currents, and wind stress.

Question 9

What is a natural tracer that can visualize plumes?

Answer 9

Sediment is used as a natural tracer to visualize coastal river plumes.

Question 10

What interaction example is mentioned in the text?

Answer 10

An interaction between a plume and internal waves, with a thermal plume moving east while internal waves move north.

Question 11

How does coastal upwelling impact marine ecosystems?

Answer 11

Coastal upwelling increases productivity by bringing nutrient-rich waters to the surface.

Question 12

What role do internal waves play in sediment transport?

Answer 12

Internal waves generate strong enough velocities to suspend and transport sediment along the shelf.

Question 13

How does the thermocline tilt affect nutrient delivery?

Answer 13

upward-tilt brings cold nutrient-rich waters nearshore, while a downward tilt does not deliver nutrients to nearshore areas.

Question 14

How do local winds contribute to variability in coastal upwelling?

Answer 14

Changes in local wind direction and speed, often influenced by local mountains, cause variability in coastal upwelling.

Question 15

What is the spatial scale of internal waves along the shelf?

Answer 15

Internal waves have length scales of ~O(10s km) and horizontal scales of ~O(10s - 1 km).

Question 16

What could disrupt understanding of headland vortices?

Answer 16

Observational challenges and the need for resolved spatial scales

Question 17

Why is the coastal jet described as unstable?

Answer 17

The coastal jet forms meanders and can break like waves, leading to instability.

Question 18

What does the variability in coastal upwelling indicate?

Answer 18

local conditions significantly influence effectiveness of upwelling processes.

Question 19

How do nutrients from internal waves benefit kelp forests?

Answer 19

Nutrient-rich waters reaching kelp forests support their growth and health.

Question 20

What does increased productivity in ecosystems correlate with?

Answer 20

nutrient availability due to upwelling and river plumes.

Question 21

How do internal waves interact with the thermocline?

Answer 21

Internal waves cause tilting of thermocline, influencing availability of nutrients in nearshore habitats.

Question 22

What is one effect of wind stress on coastal processes?

Answer 22

Wind stress affects strength of river plumes and their mixing with ambient waters.

Question 23

What phenomenon is associated with the point of coastal headlands?

Answer 23

The formation of headland vortices, which mix and transport water across the shelf.

Question 24

How do seasonal patterns relate to upwelling phenomena?

Answer 24

Upwelling can show variability through seasonal patterns influenced by wind conditions.

Question 25

What is a method for studying systems with low flow rates?

Answer 25

Using dye to visualize the behavior of coastal plumes is a common method.

Question 26

What determines the fate of exported water and nutrients?

Answer 26

Coastal processes

Question 27

How do changes in coastline geometry affect river plume dynamics?

Answer 27

can alter mixing pathways and fate of river plumes in coastal environments.

Question 28

Why type are interactions between different coastal processes analyzed?

Answer 28

Interactions, such as those between bore and headland vortices, are analyzed to understand their combined effects.

Question 29

How do warmer coastal waters compare to deeper waters?

Answer 29

Warmer waters often have lower nutrient concentrations, while deeper waters are richer in nutrients.

Question 30

How does the efficiency of fresh water export vary?

Answer 30

Freshwater export efficiency varies globally and is influenced by local geological and meteorological conditions.

Question 31

What role does Coriolis force play in ocean dynamics?

Answer 31

influences direction of water movement due to Earth’s rotation, thereby affecting coastal currents.

Question 32

What do prominent filaments associated with upwelling indicate?

Answer 32

strong upwelling conditions that push cold water far offshore along the coastline.