Sensitivity of Southern Ocean overturning to wind stress changes:Role of surface restoring time scales

The influence of different surface restoring time scales on the response of the Southern Ocean overturning circulation to wind stress changes is investigated using an idealised channel model. Regardless of the restoring time scales chosen, the eddy-induced meridional overturning circulation (MOC) is found to compensate for changes of the direct wind-driven Eulerian-mean MOC, rendering the residual MOC less sensitive to wind stress changes. However, the extent of this compensation depends strongly on the restoring time scale: residual MOC sensitivity increases with decreasing restoring time scale. Strong surface restoring is shown to limit the ability of the eddy-induced MOC to change in response to wind stress changes and as such suppresses the eddy compensation effect. These model results are consistent with qualitative arguments derived fromresidual-mean theory andmay have important implications for interpreting past and future observations

The Impact of Atmospheric Storminess on the Sensitivity of Southern Ocean Circulation to Wind Stress Changes

The influence of changing the mean wind stress felt by the ocean through alteration of the variability of the atmospheric wind, as opposed to the mean atmospheric wind, on Southern Ocean circulation is investigated using an idealised channel model. Strongly varying atmospheric wind is found to increase the (parameterised) near-surface viscous and diffusive mixing. Analysis of the kinetic energy budget indicates a change in the main energy dissipation mechanism. For constant wind stress, dissipation of the power input by surface wind work is always dominated by bottom kinetic energy dissipation. However, with time-varying atmospheric wind, near surface viscous dissipation of kinetic energy becomes increasingly important as mean wind stress increases. This increased vertical diffusivity leads to thicker mixed layers and higher sensitivity of the residual circulation to increasing wind stress, when compared to equivalent experiments with the same wind stress held constant in time. This may have implications for Southern Ocean circulation in different climate change scenarios should the variability of the atmospheric wind change rather than the mean atmospheric wind

Does the sensitivity of Southern ocean circulation depend upon bathymetric details?

The response of the major ocean currents to changes in wind stress forcing is investigated with a series of idealized, but eddy-permitting, model simulations. Previously, ostensibly similar models have shown considerable variation in the oceanic respons

The regional employment returns from wave and tidal energy: A Welsh analysis

The paper examines the expected regional employment returns connected to the development of tidal stream and wave-based electricity generation in a UK region - Wales. New employment provides economic development opportunities and the paper demonstrates that there is a need to develop the evidence base on these regional employment impacts. It addresses how far a region which is adjacent to significant marine resources is likely to benefit from a change in the energy generation mix which could feature more wave and tidal stream technologies

Priority sectors in city regions? Some issues from a study of the Cardiff Capital Region

The City Region is becoming the spatial focus for economic development policy across many parts of the European continent. But these functional regions have taken on a new impetus in the UK with the introduction of ‘city deals’ aimed at improving network and coordination of actors in local authorities. One of the goals of city regions is to improve industrial policy particularly lacking since the abolition of many of the Regional Development Agencies across the UK. However, city regions in developing policy appear to be following in an unquestioning manner the industrial priorities of earlier institutions, and nowhere is this more obvious than in the case of the identification of priority industry development sectors. Too often the selection of industries and clusters for special support has been undertaken in an unquestioning manner. In this paper we focus on the case of the Cardiff Capital Region. We review approaches to identify priority sectors in this case and the problems associated with this policy approach

The Effect of Nitrogen Rates and Plant Density on Grain Yield Components and Persistence in Intermediate Wheatgrass (\u3ci\u3eThinopyrum intermedium\u3c/i\u3e) and Mountain Rye (\u3ci\u3eSecale strictum\u3c/i\u3e)

Intermediate wheatgrass (IWG; Thinopyrum intermedium) and Mountain Rye (Mtn Rye; Secale strictum) have potential for release as dual-purpose (grazing and grain production) perennial grains in Australia due to their superior longevity compared to hybrid perennial wheats. Initially developed as perennial forage grasses, few management guidelines exist to inform agronomic practices to maximise grain yields and profitability in Australian environments. An experiment was established in 2020 to examine the effect of plant density and nitrogen rates on grain yield components. The experiment compared the two species (IWG, Mtn Rye) sown at three plant densities (50, 100 and 200 plants/m2) with three nitrogen rates (0, 100, 200 kg/ha N). Overall, in the first year of production, Mtn Rye had higher grain yields than Kernza although yield decreased with increasing N rates. With further selection for floret fertility and seed size, Mtn Rye could prove a successful candidate for a perennial grain crop in Australia

Effects of Learning Strategy Awareness on Learning, Learners, and Instructor

Occupational and Adult Educatio

Seasat SAR test of the Virginian Sea Wave Climate Model

Coastal wave refraction imaged by the Seasat Synthetic Aperture Radar is compared to simulations produced by the Virginian Sea Wave Climate Model. Seasat SAR passes 974 at Cape Hatteras, and 974 and 1404 at Long Island, were examined using OFT and ZTS methods. Results generally confirm the validity of linear wave theory in modeling of shallow-water wave refraction --roughly half the deviations between VSWCM and SAR data for direction and wavelength are within 2 degrees and 10 meters. Convergence of wave orthogonals is found in predicted caustic regions. Available bathymetric data were adequate for the analysis. Some details in the pattern of deviations near Cape Hatteras suggested current shear and tidal effects associated with the Gulf Stream

Turbulent drag on a low-frequency vibrating grid in superfluid He-4 at very low temperatures

We present measurements of the dissipative turbulent drag on a vibrating grid in superfluid He-4 over a wide range of (low) frequencies. At high velocities, the dissipative drag is independent of frequency and is approximately the same as that measured in normal liquid He-4. We present measurements on a similar grid in superfluid He-3-B at low temperatures which shows an almost identical turbulent drag coefficient at low frequencies. However, the turbulent drag in He-3-B is substantially higher at higher frequencies. We also present measurements of the inertial drag coefficient for grid turbulence in He-4. The inertial drag coefficient is significantly reduced by turbulence in both superfluid and normal liquid He-4