Karteikarten
Oceanography
Karten in diesem Stapel (34)
- 1ThermoclineThe range of depths where the rate of change, the gradient of tempereature, is large.
- 2PycnoclineSince temp and density are closely related, the thermocline also tends to be the layer where density gradient is greatest.
- 3Equation of Motion
- 4After Approximation Equation of Motion, Momentum in u
- 5After Approximation Equation of Motion, Momentum in v
- 6After Approximation Equation of Motion, Momentum in wHydrostatic Approximation
- 7f-plane approximationIs a cartesian coord system in which the Coriolis force is assumed const.
-Useful for describing flow in regions small compared with the radius of the earth and larger than a few kilometers.
- 8B-Plane Approximation-Coriolis force is assumed to vary linearly with latitude
Useful for describing flows that extend over large distances and in numerical calculations of basin and global scale flows
-winds effect the bottom layer due to B-effect
-Where B_y = B(y-y0)
- 9Rossby Number-Ratio of inertial forces to Coriolis forces
-dimensionless number used in describing fluid flow.
-it characterizes the importance of Coriolis accelerations arising from planetary rotation.
-A small Rossby number (low-pressure system) signifies a system which is strongly affected by Coriolis forces, and a large Rossby number (tornados) signifies a system in which inertial and centrifugal forces dominate.
R_o=u/Lf - 10Geostrophic Balance-The balance between the Coriolis force and the pressure gradient force.
-Results in geostrophic winds/flows which are directed parallel to isobars
-Ocean flow is in geostrophic balance
- 11Geostrophic Balance: Northern HemiGeostrophic velocity is parallel to isobars such that the high-pressure level is to the right of the current velocity
- 12Geostrophic Balance: Southern HemiGeostrophic velocity is parallel to isobars such that the high-pressure level is to the left of the current velocity
- 13Approximation of non-rotating planef=0
WOrks for processes like waves, circulation in small harbors with a large Rossby Number - 14Reynolds stressDescribes the impact of turbulent fluctuations on the mean flow.
- 15Ekman PumpingThe curl of the wind stress determines the rate of vertical velocity at the bottom of the Ekman layer.
-Negative W_E are areas of high atmospheric pressure and anticyclonic winds. These are areas of convergence of Ekman transports that pump surface water downwards.
-Positive W_E, low atmospheric pressure, cyclonic winds, divergence of Ekman transports that pump surface water upward from the ocean interior - 16Ekman Boundary ConditionsSurface- Turbulent friction is caused by the wind. Top Picture
-At bottom (-D_E) we can assume that u=o, v=o
- 17Capital U and VTransport: The amount of water moving through the water column
- 18DivergentDivergent= du/dx + dv/dy
div>0 divergent - 19ConvergentConvergent = -divergent
div<0 - 20non-divergentdivergent= 0
parallel flow - 21Depth Integrated FlowMust be horizontally non-div, div=0
- 22Water MassA distinct body of water that originated in a particular area with a particular salinity and temp.
- 23How are Ocean Depth Characteristics Changed?Are changed by isopycnal advection, mixing, and diapycnol diffusion
- 24Water Mass Mixing Types-Advection (mostly along isopycnal lines) and isopycnal mixing
-Diapycnal diffusion (along and across isopycnal lines)
-Interaction with topography - 25dyapicnal mixingMixing across isopycnal lines
- 26Isopycnal mixingmixing along constant density isobars
- 27Deep Circulation is Driven byvertical mixing, which is largest above mid-ocean ridges, near seamounts, and in strong boundary currents
- 28Where does deep convection produce bottom wateroccurs only in the far north Atlantic and at a few locations around Antarctica.
- 29Inertial OscillationChanges in wind stress that produce transient oscillations in the ocean
- 30Wind StressThe wind friction force per unit area, (tau_sx, tau_sy)
- 31Boundary Conditions for Ekman Balance-At the surface the turbulent friction is caused by the wind.
- 32Two major forcings which drive the ocean circulationa) Surface winds -> Ekman Pumping
b) surface heat and freshwater fluxes which determine the surface flux of density (buoyancy) - 33Ekman Pumping: When w_e is -ivHACD
High Atm_press
Anticyclonic winds
Convergence of Ekman transport
Down pumping - 34Ekman Pumping: When w_e is +ivLCDU
Low Atm_press
Cyclonic
Divergence of Ekman transport
Uppumping
Informationen
- Beschreibung
- Karteikarten am Oceanography , erstellt von Igor Tchouiko am 22/01/2019.
- Erstellt von
- Igor Tchouiko
- Aufrufe
- 27
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