Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 135 for “"Ekman"”.
-
Experiments on Ekman layer instability.
Massachusetts Institute of Technology. Dept. of Meteorology. Thesis. 1966. Ph.D.
-
Secondary instability in Ekman boundary flow by David B. Zaff.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1987.
-
An experimental study of the interactions between Ekman layers and an annular vortex
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1969.
-
Linear and nonlinear stratified spindown over sloping topography
… along-isobath flow induces cross-isobath Ekman flows. Ekman advection of buoyancy weakens the vertical circulation and slows spindown. Upslope (downslope) Ekman flows tend to inject (remove) potential vorticity into (from) the ocean. Momentum advection and nonlinear buoyancy advection are …
-
Linear and nonlinear stratified spindown over sloping topography
… along-isobath flow induces cross-isobath Ekman flows. Ekman advection of buoyancy weakens the vertical circulation and slows spindown. Upslope (downslope) Ekman flows tend to inject (remove) potential vorticity into (from) the ocean. Momentum advection and nonlinear buoyancy advection are …
-
Shelf currents, ice and wind : a numerical modeling study
… The wind stress generates shoreward surface Ekman transport and the barotropic current generates an offshore bottom Ekman transport. In both cases, the Ekman transport causes the creation of mixed layers and a relationship describing the mixed layer thickness is derived relating the cross …
-
Annual and Interannual Variability in the Wind Field and the Hydrography Along the Seward Line in the Northern Gulf of Alaska
… wind stress curls which promote upwelling due to Ekman pumping. Calculations show that the transport due to this upwelling is 25% - 50% of the transport due to Ekman transport. On average Ekman transport produces downwelling while the transport due to Ekman pumping produces upwelling. The effect …
-
Experiments in a rotating source-sink annulus
… velocities are measured over a large range of Ekman Reynolds number and Rossby number. Differing probe configurations are used to investigate the corresponding motions in spatially separated regions of the annulus. The steady interior circulation field exhibits a strong dependence on the …
-
Time-dependent ventilated thermocline
… of characteristics. The effect of a varying Ekman pumping is investigated. In a shadow zone, it is found that the driving due to the Ekman pumping is mainly balanced by the propagation of planetary waves. However, in a ventilated zone, the cold advection of subducted water plays the essential …
-
Towards Improved Estimates of Upper Ocean Energetics
… In this research, geostrophic, ageostrophic, Ekman, and total current decompositions are all used to calculate wind work. Geostrophic currents are formed by the balance of surface pressure gradients and the Coriolis effect. Ageostrophic currents, on the other hand, are difficult to calculate …
-
Dynamics of freshwater plumes: observations and numerical modeling of the wind-forced response and alongshore freshwater transport
… in alongshore wind forcing. Consistent with Ekman dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to a few Rossby radii. Near-surface current meters show significant …
-
Dynamics of freshwater plumes : observations and numerical modeling of the wind-forced response and alongshore freshwater transport
… in alongshore wind forcing. Consistent with Ekman dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to a few Rossby radii. Near-surface current meters show significant …
-
Beyond static representations: development of a multi-channel, dynamic assessment of emotion perception
… in humans has a long and rich literature base. Ekman’s (Ekman, 1972; Ekman & Friesen, 1971) research on the universal recognition of emotions represents some of the earliest work in the area of emotion recognition. However, with the exception of recent work on synthesized faces to examine facial …
-
On the scale interaction between African easterly waves and convention
… Highly simplified physical processes, including Ekman damping and relaxation, are included to study the dynamic equilibrium problem. Similar to the results of observation, the barotropic process is important during the linear stage of the life cycle. The structure during the nonlinear stage is …
-
A numerical modelling study of Port Alfred upwelling along the inshore edge of Agulhas current
… driven by northeasterlies inducing offshore Ekman transport and divergence. In contrast, stronger southwesterlies during winter could cause vertical mixing. To determine the Port Alfred upwelling’s driving mechanism during the mean state, we computed the terms of the generalized Ekman pumping …
-
Generation of mid-ocean eddies : the local baroclinic instability hypothesis
… sheared mean flow and dissipated through bottom Ekman friction, Explanations are sought for two observed features of mid-ocean eddies: 1) substantial energy is retained in the baroclinic mode and in the associated deformation radius (Rd) scale, and 2) the ratio of eddy to mean kinetic energy is …
-
Comparative analysis of the seasonal sea surface temperature & wind stress in the four major eastern boundary current systems
… of 10 x 10 was used to derive the offshore Ekman Transport in each of the regions. The offshore Ekman Transport was used to supplement the description of SST's in each system. Principal Component Analysis was used to investigate the variance structure of the anomalies of the sea surface …
-
The dynamics of bottom boundary currents in the ocean
… Sea water to reach the ocean floor. A turbulent Ekman layer model with a constant eddy viscosity is also formulated. The properties of the flow are defined in terms of the layer thickness variable d(x,y), whose governing equation is judged intractable for the general case. However, limiting forms …
-
The dynamic role of ridges in a β-plane channel : towards understanding the dynamics of large scale circulation in the Southern Ocean
… the question of how the northward surface Ekman transport out of the circumpolar ocean is returned is discussed in a two-layer model with an infinitesimally thin surface Ekman layer on top of a homogeneous layer of water in a rather idealized Southern Ocean basin. First, the case with a …
-
Wind-Induced Exchange in Semi-Enclosed Basins
… of the earth's rotation depended on the ratio of Ekman depth (<em>d</em>) to the maximum basin's depth (<em>h</em>). The solution tended to that described in a non-rotating system as <em>h/d</em> remained equal to or below one. For higher values of <em>h/d</em>, the longitudinal flow was axially …
Page 1 of 7