586 research outputs found
Disconnections in management theory and practice: poetry, numbers and postmodernism
This essay is concerned with what Abbinnett described as fundamental to the discourses of social science: truth and its construction. The central problem around which the narrative is built is a growing disconnection in one area of social science, management research, between how truth is frequently defined and used and the approaches taken to constructing that truth. The result of this is an intellectual impurity whereby management research occupies an incoherent intellectual space somewhere between modernism and postmodernism. Our argument is that, for a host of probable reasons, management research in many areas is dominated by the search for rational and scientific truth through the use of quantitative methodologies underpinned by a positivist philosophy. The result of this is frequently truth diluted rather than truth distilled. The essay discusses different routes to establishing a type of truth, the location of management research within a modern-postmodern continuum and the implications of this for management researchers. We begin, however, with a brief discussion of the nature of truth in social science
Impact of geothermal heating on the global ocean circulation
The response of a global circulation model to a uniform geothermal heat flux of 50 mW m-2 through the sea floor is examined. If the geothermal heat input were transported upward purely by diffusion, the deep ocean would warm by 1.2°C. However, geothermal heating induces a substantial change in the deep circulation which is larger than previously assumed and subsequently the warming of the deep ocean is only a quarter of that suggested by the diffusive limit. The numerical ocean model responds most strongly in the Indo-Pacific with an increase in meridional overturning of 1.8 Sv, enhancing the existing overturning by approximately 25%
Is there really a value in entrepreneurship education?
This paper considers whether entrepreneurship education has a value outside of the education institutions in which it takes place. The paper takes an indirect form of enquiry and argues that entrepreneurship education is driven by three factors; the growing emphasis on supply side policy interventions in the economy; the emphasis placed on the agency of management in the growing literature on globalisation and international reforms to public sector organisations. The paper concludes that there is a tension between the activity as descriptive and the activity as promotion and until this tension is resolved it is unlikely that there will be clarity about the value of this form of education
Geothermal Heating and its Influence on the Meridional Overturning Circulation
The effect of geothermal heating on the meridional overturning circulation is examined using an idealized, coarse-resolution ocean general circulation model. This heating is parameterized as a spatially uniform heat flux of 50 mW m-2 through the (flat) ocean floor, in contrast with previous studies that have considered an isolated hotspot or a series of plumes along the mid-Atlantic ridge. The equilibrated response is largely advective: a deep perturbation of the meridional overturning cell on the order of several Sv is produced, connecting with an upper-level circulation at high latitudes, allowing the additional heat to be released to the atmosphere. Risingmotion in the perturbation deep cell is concentrated near the equator. The upward penetration of this cell is limited by the thermocline, analogous to the role of the stratosphere in limiting the upward penetration of convective plumes in the atmosphere. The magnitude of the advective response is inversely proportional to the deep stratification; with a weaker background meridional overturning circulation and a less stratified abyss, the overturning maximum of the perturbation deep cell is increased. This advective response also cools the low-latitude thermocline. The qualitative behavior is similar in both a single hemisphere and double hemisphere configuration.The anomalous circulation driven by geothermal fluxes is more substantial than previously thought. We are able to understand the structure and strength of the response in the idealized geometry and further extend these ideas to explain the results of Adcroft et al. [2001], where the impact of geothermal heating was examined using a global configuration
3D cut-cell modelling for high-resolution atmospheric simulations
Owing to the recent, rapid development of computer technology, the resolution
of atmospheric numerical models has increased substantially. With the use of
next-generation supercomputers, atmospheric simulations using horizontal grid
intervals of O(100) m or less will gain popularity. At such high resolution
more of the steep gradients in mountainous terrain will be resolved, which may
result in large truncation errors in those models using terrain-following
coordinates. In this study, a new 3D Cartesian coordinate non-hydrostatic
atmospheric model is developed. A cut-cell representation of topography based
on finite-volume discretization is combined with a cell-merging approach, in
which small cut-cells are merged with neighboring cells either vertically or
horizontally. In addition, a block-structured mesh-refinement technique is
introduced to achieve a variable resolution on the model grid with the finest
resolution occurring close to the terrain surface. The model successfully
reproduces a flow over a 3D bell-shaped hill that shows a good agreement with
the flow predicted by the linear theory. The ability of the model to simulate
flows over steep terrain is demonstrated using a hemisphere-shaped hill where
the maximum slope angle is resolved at 71 degrees. The advantage of a locally
refined grid around a 3D hill, with cut-cells at the terrain surface, is also
demonstrated using the hemisphere-shaped hill. The model reproduces smooth
mountain waves propagating over varying grid resolution without introducing
large errors associated with the change of mesh resolution. At the same time,
the model shows a good scalability on a locally refined grid with the use of
OpenMP.Comment: 19 pages, 16 figures. Revised version, accepted for publication in
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Freshwater transport in the coupled ocean-atmosphere system: a passive ocean
Conservation of water demands that meridional ocean and atmosphere freshwater transports (FWT) are of equal magnitude but opposite in direction. This suggests that the atmospheric FWT and its associated latent heat (LH) transport could be thought of as a \textquotedblleft coupled ocean/atmosphere mode\textquotedblright. But what is the true nature of this coupling? Is the ocean passive or active?
Here we analyze a series of simulations with a coupled ocean-atmosphere-sea ice model employing highly idealized geometries but with markedly different coupled climates and patterns of ocean circulation. Exploiting streamfunctions in specific humidity coordinates for the atmosphere and salt coordinates for the ocean to represent FWT in their respective medium, we find that atmospheric FWT/LH transport is essentially independent of the ocean state. Ocean circulation and salinity distribution adjust to achieve a return freshwater pathway demanded of them by the atmosphere. So, although ocean and atmosphere FWTs are indeed coupled by mass conservation, the ocean is a passive component acting as a reservoir of freshwater
Sensitivity and variability redux in hot-Jupiter flow simulations
We revisit the issue of sensitivity to initial flow and intrinsic variability in hot-Jupiter atmospheric flow simulations, originally investigated by Cho et al. (2008) and Thrastarson & Cho (2010). The flow in the lower region (~1 to 20 MPa) `dragged' to immobility and uniform temperature on a very short timescale, as in Liu & Showman (2013), leads to effectively a complete cessation of variability as well as sensitivity in three-dimensional (3D) simulations with traditional primitive equations. Such momentum (Rayleigh) and thermal (Newtonian) drags are, however, ad hoc for 3D giant planet simulations. For 3D hot-Jupiter simulations, which typically already employ strong Newtonian drag in the upper region, sensitivity is not quenched if only the Newtonian drag is applied in the lower region, without the strong Rayleigh drag: in general, both sensitivity and variability persist if the two drags are not applied concurrently in the lower region. However, even when the drags are applied concurrently, vertically-propagating planetary waves give rise to significant variability in the ~0.05 to 0.5 MPa region, if the vertical resolution of the lower region is increased (e.g. here with 1000 layers for the entire domain). New observations on the effects of the physical setup and model convergence in ‘deep’ atmosphere simulations are also presented
Mesoscale modulation of air-sea CO2 flux in Drake Passage
Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 6635–6649, doi:10.1002/2016JC011714.We investigate the role of mesoscale eddies in modulating air-sea CO2 flux and associated biogeochemical fields in Drake Passage using in situ observations and an eddy-resolving numerical model. Both observations and model show a negative correlation between temperature and partial pressure of CO2 (pCO2) anomalies at the sea surface in austral summer, indicating that warm/cold anticyclonic/cyclonic eddies take up more/less CO2. In austral winter, in contrast, relationships are reversed: warm/cold anticyclonic/cyclonic eddies are characterized by a positive/negative pCO2 anomaly and more/less CO2 outgassing. It is argued that DIC-driven effects on pCO2 are greater than temperature effects in austral summer, leading to a negative correlation. In austral winter, however, the reverse is true. An eddy-centric analysis of the model solution reveals that nitrate and iron respond differently to the same vertical mixing: vertical mixing has a greater impact on iron because its normalized vertical gradient at the base of the surface mixed layer is an order of magnitude greater than that of nitrate.NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center Grant Number: SMD-15-5752;
NSF MOBY project Grant Numbers: (OCE-1048926), OCE-1259388, PLR-1341647, AOAS-0944761, and AOAS-066975;
NOAA Climate Program Office Grant Number: (NA12OAR4310058)2017-03-1
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