Motion Flashcards
Laminar vs Turbulent
Laminar- one direction one speed
Turbulent- many directions many speeds
Laminar–> Turbulent
Can happen at any boundary of different densities, air vs water, two layers of waters.
caused by frictions.
Reynolds Number
standard measure in fluid mechanics of the ratio of inertial
and viscous forces in a flow. Re = inertial forces/viscous forces =
turbulent flow/laminar flow
Flow is laminar when Re is low
small organisms have small Re
Turbulent water (eddies) (Kz)
Is a measure of the rate of exchange or intensity of
mixing across a plane.
without motion, Eddies exchange heat and gas diffusions
happens more in the epilimnion
WIND
Epilimnion mixed by surface wind waves, currents, gyres,
Motion in the epilimnion/ Ekman spiral
Coriolis Effect, surface 45 degrees right of wind direction in northern hemisphere
Motivated by wind
Surface waves
wind pushes water and creates a spiral of force
the wave of force moves in a circle , Water only moves up and down
Surface waves become smaller as they go down
Langmuir Circulation
Upwelling (divergence zone)- brings up sediments
downwelling (convergence zone)
Surface Seiches
Massive waves that shove the entire lake around
caused by strong consistent winds
Motion in the metalimnion - stratified conditions
Internal gravity waves- Nodes are where the thermocline tilt or bend.
Kelvin-Helmholtz mixing -funny waves of metalimnion that leave a pace of it in the epilimnion