https://oceanwiki.ethz.ch/ 2026-10-01T23:07:55+00:00 https://oceanwiki.ethz.ch/ https://oceanwiki.ethz.ch/lib/exe/fetch.php?media=wiki:logo.png text/html 2015-03-24T09:41:05+00:00 Anonymous (anonymous@undisclosed.example.com) https://oceanwiki.ethz.ch/doku.php?id=lecture7:bulkformula&rev=1427190065&do=diff Bulk Formula Author: Anna Muntwyler Edited by Gabriel Zehnder Surface wind stress In physical oceanography and fluid dynamics, the wind stress is the shear stress exerted by the wind on the surface of large bodies of water. It is the force component parallel to the surface, per unit area, as applied by the wind on the water surface. The wind stress is affected by the wind speed, the shape of the wind waves and the atmospheric stratification. It is one of the components of the air–sea interac… text/html 2016-08-11T10:52:42+00:00 Anonymous (anonymous@undisclosed.example.com) https://oceanwiki.ethz.ch/doku.php?id=lecture7:ekman_pumping&rev=1470912762&do=diff Ekman Depth and Ekman Pumping Ekman Layer Depth The thickness of the Ekman layer is arbitrary because the Ekman currents decrease exponentially with depth. Ekman proposed that the thickness be the depth DE at which the current velocity is opposite the velocity at the surface, which occurs at a depth $ D_E = \pi/a $$$ D_E = \sqrt{\frac{2\pi A_z}{f}} $$$ D_E $$ A_z $ text/html 2015-05-05T10:29:30+00:00 Anonymous (anonymous@undisclosed.example.com) https://oceanwiki.ethz.ch/doku.php?id=lecture7:ekman&rev=1430821770&do=diff Ekman Transport Authors: Anna Muntwyler, Ana Cristina Franco Novela The term Ekman transport refers to the volume of water in the surface layer (layer affected by wind) of the ocean that is transported at right angles to the wind direction. The direction of transport occurs at 90° to the right from the direction of the wind in the northern hemisphere and to the left in the southern hemisphere. $D_E$$D_E = \sqrt{\frac{2K_z}{f\rho}} $$\overline{u} = \frac{\tau_0}{D_E \rho f}$$m^3 s^{-1}$$kg m^{-… text/html 2015-03-24T15:19:33+00:00 Anonymous (anonymous@undisclosed.example.com) https://oceanwiki.ethz.ch/doku.php?id=lecture7:lawofthewall&rev=1427210373&do=diff Law of the Wall Authors: Deyan and Thomas Edited by: Ari Feinberg Fluid movement along a boundary Fluids moving along a boundary follow either laminar (straight) or turbulent (mixed) flow. There are several layers within the fluid flowing along a surface boundary (Figure 1). These layers, from bottom to top, are:$k_{c_i}$$k_T$$\nu$$k_{turb}$$z_0$$\tau$$\tau=k\vec\nabla\overline{u}$$\tau$$k$$\overline{u}$$$\bar u(z)=\dfrac{\sqrt{\tau/\rho}}{\kappa}\log\dfrac{z}{z_0}$$$\overline{u}$$z$$\tau$$\… text/html 2026-03-25T06:00:39+00:00 Anonymous (anonymous@undisclosed.example.com) https://oceanwiki.ethz.ch/doku.php?id=lecture7:reynoldsdecomp&rev=1774418439&do=diff Reynolds Decomposition Author: Elisa Lovecchio The description of the dynamics of a turbulent fluid Wikipedia>Turbulence is extremely complicated because of the complexity, unpredictability and chaotic motion that characterizes such a system, visible on a very wide range of scales. ${u}$${\bar{u}}$${u'}$${\vec{u}=\bar{\vec{u}}}$\begin{equation*} { ^t\bar{u}=\frac{1}{\Delta t} \int_{0}^{\Delta t} u(t,\vec{x}) dt } \end{equation*}\begin{equation*} { ^s\bar{u} =\frac{1}{ V} \int \int \int u(t,… text/html 2015-03-24T08:47:25+00:00 Anonymous (anonymous@undisclosed.example.com) https://oceanwiki.ethz.ch/doku.php?id=lecture7:turbdiffusion&rev=1427186845&do=diff Turbulent Diffusion Author: Sarah Aepli Rewritten by: Franziska Genter, Magdalena Gisiger, Judith Riedo Turbulent Flow and Turbulent Diffusion Turbulence is a term, which is known and used in daily life, mostly regarding aviation and weather forecasts. \begin{equation*} \vec{\bigtriangledown} \vec{u} = 0 \end{equation*}$U$$v$$L$\begin{equation*} $$ \mathsf{Re_c_r_i_t} $$v$$p$$T$\begin{equation*} \tau = k \vec{\bigtriangledown} \vec{u} \end{equation*}\begin{equation*} \frac{D\vec{u}}{\ Dt}} …