The Australian Metropolis: A Planning History: By S. Hamnett and R. Freestone.     

Caroline Miller 《New Zealand geographer》2001,57(1):59-60

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Stably stratified flows in meteorology     

J. C. R. Hunt  G. J. Shutts  S. H. Derbyshire 《Dynamics of Atmospheres and Oceans》1996,23(1-4)

It is generally believed by those undertaking research in the fundamental aspects of geophysical fluid dynamics and meteorology that their results contribute to the improvements to numerical weather prediction and in practical weather forecasting. However, the techniques whereby the appropriate research results are selected and incorporated into the numerical models are not widely known, particularly the methods for representing the phenomena whose horizontal scale is less than that of the grid boxes.(say, 50 km). Some accounts of numerical weather prediction imply that the representation of subgrid-scale phenomena is formally similar to classical physics. In fact, atmospheric motions on these scales are not like molecular motions in an ideal gas, but show considerable structure, approximating to combinations of various idealized states. Great skill and experience in this specialized activity has been applied to deciding on these states, finding physical criteria for defining them and then modelling the relevant phenomena occurring on this scale. In this paper, we focus on a restricted range of phenomena associated with stably stratified flows, notably mountain waves, convection and clouds, and boundary layer phenomena. This category provides many examples of structures which need to be considered in detail to reconstruct the large-scale picture accurately, as well as in local forecasting.  相似文献   

On mass transport in deep water waves     

J. N. Hunt  S. K. A. Massoud 《Pure and Applied Geophysics》1962,53(1):65-76

Summary Various formulations of the mass-transport problem are compared for progressive waves in deep water. In order to calculate the mass-transport velocity as a function of depth in the main body of the fluid, it is necessary to include the effect of viscous wave attenuation. It is shown that the usual assumptions of periodicity in distance and attenuation with time or periodicity in time and attenuation with distance, are both physically unsatisfactory. The first does not specify a unique solution, and the second is incompatible with the assumption of zero surface stress. A certain critical constant tangential wind stress will maintain strictly time-periodic deep water waves. The corresponding attenuation with distance is then calculated to order ³. A constant tangential stress greater or less than the critical causes waves, necessarily decaying with distance, to grow or decay with time.  相似文献   

The opacity of some local Martian dust storms observed by the Viking IRTM     

Garry E. Hunt  Elizabeth A. Mitchell  Alan R. Peterfreund 《Icarus》1980,41(3):389-399

In this paper we analyze some Viking infrared thermal mapping (IRTM) measurements of local Martian dust storms observed in the southern tropical region of the planet between L_s=225 and 262°. The derived opacities of these storms show that in the most opaque regions of the cloud, the optical thickness may be ≈6. Away from the individual clouds, the opacity is ≈2, which is still about four times the background level of dustiness in the Martian atmosphere. We find considerable structure in the derived opacity which will create corresponding variations in the atmospheric heating, which in turn may have an important feedback upon the local winds.  相似文献   

Influence of wind upon water quality in Liverpool Bay     

P. Foster  K.B. Pugh  D.T.E. Hunt  G.M. Foster  G. Savidge 《Marine pollution bulletin》1977,8(1):11-12

Comprehensive distribution patterns of physical and chemical characteristics have been obtained from a series of cruises in Liverpool Bay. The marked feature of these distributions was their temporal variability, suggesting that the surface residual circulation is also temporally variable. The influence of wind stress upon the circulation pattern and hence water quality of this sea area is illustrated.  相似文献   

Ecohydrology--why hydrologists should care   总被引：1，自引：0，他引：1  

Hunt RJ  Wilcox DA 《Ground water》2003,41(3):289-289

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Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sediments from Hong Kong   总被引：4，自引：0，他引：4  

Müller JF  Gaus C  Prange JA  Päpke O  Poon KF  Lam MH  Lam PK 《Marine pollution bulletin》2002,45(1-12):372-378

Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in 14 sediment samples collected from four sites in the Mai Po Marshes Nature Reserve (within a RAMSAR Site) and from another six sites in Victoria Harbour and along the Hong Kong coastline. Elevated levels of PCDDs, and particularly OCDD, were detectable in all samples collected from the Mai Po Marshes and five of the six sites. In contrast to PCDDs, PCDFs were mainly found in sediment samples collected from industrial areas (Kwun Tong and To Kwa Wan) in Victoria Harbour. PCDD/F levels and congener profiles in the samples from the Mai Po Marshes Nature Reserve in particular show strong similarities to those reported in studies which have attributed similar elevated PCDD concentrations to nonanthropogenic PCDD sources.  相似文献   

Foreword: Ground Water Flow Modeling with the Analytic Element Method     

Hendrik M. Haitjema  Randall J. Hunt  Igor Jankovic  Wim J. de Lange 《Ground water》2006,44(1):1-2

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The Medieval Warm Period, the Little Ice Age and simulated climatic variability   总被引：1，自引：0，他引：1  

B. G. Hunt 《Climate Dynamics》2006,27(7-8):677-694

The CSIRO Mark 2 coupled global climatic model has been used to generate a 10,000-year simulation for ‘present’ climatic conditions. The model output has been analysed to identify sustained climatic fluctuations, such as those attributed to the Medieval Warm Period (MWP) and the Little Ice Age (LIA). Since no external forcing was permitted during the model run all such fluctuations are attributed to naturally occurring climatic variability associated with the nonlinear processes inherent in the climatic system. Comparison of simulated climatic time series for different geographical locations highlighted the lack of synchronicity between these series. The model was found to be able to simulate climatic extremes for selected observations for century timescales, as well as identifying the associated spatial characteristics. Other examples of time series simulated by the model for the USA and eastern Russia had similar characteristics to those attributed to the MWP and the LIA, but smaller amplitudes, and clearly defined spatial patterns. A search for the frequency of occurrence of specified surface temperature anomalies, defined via duration and mean value, revealed that these were primarily confined to polar regions and northern latitudes of Europe, Asia and North America. Over the majority of the oceans and southern hemisphere such climatic fluctuations could not be sustained, for reasons explained in the paper. Similarly, sustained sea–ice anomalies were mainly confined to the northern hemisphere. An examination of mechanisms associated with the sustained climatic fluctuations failed to identify a role for the North Atlantic Oscillation, the El Niño-Southern Oscillation or the Pacific Decadal Oscillation. It was therefore concluded that these fluctuations were generated by stochastic processes intrinsic to the nonlinear climatic system. While a number of characteristics of the MWP and the LIA could have been partially caused by natural processes within the climatic system, the inability of the model to reproduce the observed hemispheric mean temperature anomalies associated with these events indicates that external forcing must have been involved. Essentially the unforced climatic system is unable to sustain the generation of long-term climatic anomalies.  相似文献   

Comparison of TL multiple aliquot, single grain GLSL SAR and C-14 ages for the Puritjarra, Australia, rock shelter     

J.R. Prescott  F.M. Williams  C.D. Hunt 《Quaternary Geochronology》2007,2(1-4):344-349

We report single-grain quartz luminescence ages for the Puritjarra rock shelter, with the aim of resolving an apparent discrepancy between ages obtained by ¹⁴C and a variety of luminescence methods, previously reported. Ages now found at all depths to 75 cm (ages to 30 ka) can be interpreted as largely resolving the differences. This implied caveat arises because single-grain methods are statistically inefficient. As a consequence, a degree of interpretation is inevitable in analysing the data. The emphasis in the present paper is an analysis making use of weighted histograms. The measurements by single grain OSL and ¹⁴C, including ABOX–SC, taken together, can be regarded as compatible. They indicate human occupation of the Puritjarra rock shelter at least as early as 30 ka BP.  相似文献