QCM : Fundamentals of Physical Oceanography — 9 questions

Questions et réponses du QCM

1. What is hydrostatic equilibrium in physical oceanography?

The condition where temperature and salinity are uniformly distributed in the water column
The balance between the vertical pressure gradient force and gravity in a stationary ocean
The balance between the Coriolis force and the pressure gradient force in large-scale flow
The state where viscous forces dominate over inertial forces in fluid motion

The balance between the vertical pressure gradient force and gravity in a stationary ocean

Explication

Hydrostatic equilibrium is the condition in a stationary ocean where the vertical pressure gradient force balances gravity, resulting in horizontal isobaric surfaces. This fundamental law simplifies the vertical momentum equations in oceanography and describes the state of rest or steady flow in the vertical direction.

2. What is hydrostatic equilibrium in physical oceanography?

The balance between light and dense water layers in the ocean
The state where vertical pressure gradient force balances gravity, resulting in no vertical acceleration
The oscillation of ocean surface due to wind conditions
The equilibrium between currents and tides in the ocean

The state where vertical pressure gradient force balances gravity, resulting in no vertical acceleration

Explication

Hydrostatic equilibrium occurs when the vertical pressure gradient force balances gravity, ensuring no net vertical acceleration, which simplifies the vertical momentum equation.

3. What is the precise definition of 'eddies' as described in the context of ocean motion objects?

Vertical movements of water caused by buoyancy differences, leading to mixing and convection.
Periodic oscillations in the water surface caused by restoring forces like gravity or Earth's rotation.
Circular currents or whirlpools resulting from fluid instabilities, generated by wind shear or current shear, involving complex force balances.
Large-scale, steady ocean currents driven primarily by wind patterns and Earth's rotation.

Circular currents or whirlpools resulting from fluid instabilities, generated by wind shear or current shear, involving complex force balances.

Explication

Eddies are defined as circular currents or whirlpools resulting from fluid instabilities, generated by wind shear or current shear, involving complex force balances, which matches the description in the content.

4. Which of the following best describes eddies in ocean flows?

Linear waves propagating across the ocean surface
Circular or spiral fluid motions caused by flow instabilities and shear
A type of standing wave associated with tides
Vertical columns of water rising from the ocean floor

Circular or spiral fluid motions caused by flow instabilities and shear

Explication

Eddies are circular or spiral motions resulting from flow instabilities or shear, playing a key role in mixing and transport processes.

5. What does the Reynolds number indicate in fluid flow?

The ratio of inertial to viscous forces, determining laminar versus turbulent flow
The speed of wave propagation in the ocean
The strength of Coriolis force effects
The ratio of salinity to temperature in seawater

The ratio of inertial to viscous forces, determining laminar versus turbulent flow

Explication

The Reynolds number measures the relative importance of inertial forces to viscous forces, indicating whether flow is laminar or turbulent.

6. Who was the first to establish the fundamental equations of fluid motion that describe ocean currents?

Leonardo da Vinci in the 15th century
Claude-Louis Navier and George Stokes in the 19th century
Albert Einstein in the early 20th century
Alexander von Humboldt in the 19th century

Claude-Louis Navier and George Stokes in the 19th century

Explication

The Navier-Stokes equations, formulated by Navier and Stokes in the 19th century, form the core description of fluid motion, including ocean currents.

7. Which property primarily contributes to seawater stratification?

The difference in piezometric pressure
Differences in temperature and salinity leading to density variations
The variation in ocean basin depths
The amount of biological activity in the water column

Differences in temperature and salinity leading to density variations

Explication

Seawater stratification is mainly caused by variations in temperature and salinity, which affect density and density-driven layering.

8. What is the main restoring force for internal waves in the ocean?

Gravity acting on displaced water layers
Coriolis force due to Earth's rotation
Surface tension of water molecules
Wind stress on the ocean surface

Gravity acting on displaced water layers

Explication

Internal waves are restored by gravity acting on density differences within water layers, propagating along density interfaces.

9. Which of the following statements best describes the effect of the Coriolis force on ocean currents?

It causes currents to accelerate vertically
It deflects moving fluid to the right in the northern hemisphere and to the left in the southern hemisphere
It energizes wave motion at the ocean surface
It causes the ocean to stratify into different density layers

It deflects moving fluid to the right in the northern hemisphere and to the left in the southern hemisphere

Explication

The Coriolis force results from Earth's rotation, deflecting fluid motion to the right in the northern hemisphere and to the left in the southern hemisphere, shaping large-scale circulation.

Révisez avec les flashcards

Mémorisez les réponses avec 9 flashcards sur Fundamentals of Physical Oceanography.

Convection — definition?

Vertical fluid movement caused by density differences.

Convection — definition?

Vertical fluid movement due to density differences.

Eddies — role?

Circular flows that enhance mixing and transport.

Voir les flashcards →

Approfondir avec la fiche

Consultez la fiche de révision complète sur Fundamentals of Physical Oceanography.

Voir la fiche →

Cours similaires

Actions et mouvement

Physique

Gel pour les veines

Grandeurs composées et conversions

Mathématiques

Réciproque de Pythagore

Mathématiques

Réussir ses études efficacement

Les émotions humaines

Crée tes propres QCM

Importe ton cours et l'IA génère des QCM avec corrections en 30 secondes.

Générateur de QCM