1902 Ekman transport

Ekman transport

• Fridtjof Nansen noticed that ice on the northern seas
• travels at an angle to the direction of the wind.
• Vagn Walfrid Ekman found this is due to the Coriolis effect,
• the ice being pushed against the wind by water at the surface,
• which, in the northern hemisphere,
• moves ninety degrees clockwise to the wind.

Ekman spiral

• Under a block of sea ice,
• where turbulence is calmed,
• each layer of water pushed by the wind
• and deflected by the Coriolis effect
• in turn deflects the layer under it,
• resulting in a descending spiral
• that tapers to nothing
• three hundred feet below the surface.

Coastal upwelling

• Every molecule in the ocean
• dances with its partners in loose companies.
• Where one turns along a shore
• another rises to take its place.

Balance of forces

• Stokes drift
• Coriolis effect
• Water viscosity
• Wind resistance
• If a balance of forces
• doesn’t magically result
• in a unified flow,
• energy is dissipated
• in turbulence.
• Yet sometimes
• off we go
• northeast.