Venus: The 17- to 38-micron spectrum     

R.A. Reed  W.J. Forrest  J.R. Houck  J.B. Pollack 《Icarus》1978,33(3):554-557

The Venus emission spectrum was measured from the NASA Lear Jet on five nights in June 1975. A cooled grating spectrometer with a resolution of γ/δγ ? 25 over the spectral interval 17 to 38μm was used. The main features in the observed spectrum are consisten with the theoretical emission spectrum of a haze of aqueous sulfuric acid droplets suspended in a CO₂ atmosphere.  相似文献   

Harbours – silting and environmental sedimentology   总被引：1，自引：0，他引：1  

Rodney L. Stevens 《Environmental Geology》2003,43(4):432-433

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Everywhere different? Globalisation and the impact of international migration on Sydney and Melbourne     

James Forrest  Michael Poulsen  Ron Johnston 《Geoforum》2003,34(4):499-510

Using a new approach to classifying migrant group concentrations, we test for evidence of the effects of globalisation, associated by some with ‘protopostmodernity’, on two Australian cities. Sydney is characterised as an emergent world city and a focus of ‘new economy’ activities. Melbourne is associated with ‘old economy’ activities, dominated by manufacturing. In the Australian context, the onset of globalisation also coincided with significant changes to immigration policy: the end of a ‘white Australia’ policy in the early 1970s in favour of a skills-based policy, regardless of race or ethnicity. We argue that the evidence of the spatial behaviour of ethnic groups for these two cities highlights the essential continuity of ethnic segregation and spatial assimilation processes in two cities where segregation levels and experience are fundamentally different from many overseas examples. We further argue for a need to recognise that context, and the ethnic experience, are everywhere different, both intra- and internationally.  相似文献   

Fluid compositions in equilibrium with silica-undersaturated magmas in the system Na<Subscript>2</Subscript>O–Al<Subscript>2</Subscript>O<Subscript>3</Subscript>–SiO<Subscript>2</Subscript>–H<Subscript>2</Subscript>O: clues to the composition of fenitizing fluids     

Robin F. Preston  Gary Stevens  Terence S. McCarthy 《Contributions to Mineralogy and Petrology》2003,144(5):559-569

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A Numerical Study Of Nocturnal Wavelike Motion In Forests     

Xinzhang Hu  Xuhui Lee  David E. Stevens  Ronald B. Smith 《Boundary-Layer Meteorology》2002,102(2):199-223

In this paper, we use a two-dimensional eddy-resolved model to investigate the instability of a parallel shear flow in a stably stratified boundary layer whose lower domain is occupied by a canopy. The results support our contention that wave motion in the canopy is initiated by shear in an air layer near the treetops. Significant modification by the wave motion of the mean velocity and temperature fields is found even before the wave reaches saturation. The wave fluxes of momentum and heat are not constant with height. Downwind tilting braids are found at the finite amplitude stage of the wave growth and could persist after wave breaking; these downwind tilting structures are believed to be the same as the temperature microfronts reported in the literature. We also present an analysis of the velocity and temperature fields of an observed wave event in the time-height domain and show that the simulation has captured the broad features of the observation.  相似文献   

Constraints on Infrasound Scaling and Attenuation Relations from Soviet Explosion Data     

J. L. Stevens  I. I. Divnov  D. A. Adams  J. R. Murphy  V. N. Bourchik 《Pure and Applied Geophysics》2002,159(5):1045-1062

—?The Institute for the Dynamics of the Geospheres (IDG) in Moscow, Russia, contains an archive of infrasound recordings from Soviet atmospheric nuclear tests that were conducted in 1957 and 1961, and has digitized the highest quality records from this data set. We have measured the infrasound signals from these records and compared them with previously developed scaling and attenuation relations. We find that the data are in best agreement with a scaling and attenuation relation developed by the Los Alamos National Laboratory (LANL) which can be written as logP = 3.37 + 0.68 logW? 1.36logR where P is zero to peak pressure amplitude in Pascals, W is the yield in kilotons, and R is the source to receiver distance in kilometers. We use the scaling relations to define an infrasound magnitude, and to estimate the detection capability of the International Monitoring System (IMS) being developed as part of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The detection threshold for the proposed 60-station IMS network is estimated to be slightly higher than the CTBT design goal of 1 kiloton in some locations.  相似文献   

Digital Rectification Techniques for Architectural and Archaeological Presentation     

P. G. Bryan  I. Corner  & D. Stevens 《The Photogrammetric Record》1999,16(93):399-415

Some exciting developments have been made recently, in the field of digital image rectification, which are of interest to both the photogrammetric specialist and non-specialist. This paper outlines the technical processes involved in generating digitally rectified images, as well as raising some of the issues that are becoming apparent when applying this modern technology to archaeological and architectural presentation.  相似文献   

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere     

Bjorn Stevens  Hélène Brogniez  Christoph Kiemle  Jean-Lionel Lacour  Cyril Crevoisier  Johannes Kiliani 《Surveys in Geophysics》2017,38(6):1371-1397

In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical troposphere—below the height, \(z_*,\) of the triple-point isotherm, \(T_*.\) The measurements are evaluated in light of understanding of how lower-tropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between \(T_*\) and the temperature at which primary ice forms gives a ‘first-mover advantage’ to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near \(T_*\) implies relative humidity reversals below \(z*\) which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically important aspects of the vertical structure of water vapor from space using only passive sensors.  相似文献   

Predicting seasonal ocean variability around New Zealand using a coupled ocean-atmosphere model     

Catherine O. de Burgh-Day  Claire M. Spillman  Craig Stevens  Oscar Alves  Graham Rickard 《新西兰海洋与淡水研究杂志》2019,53(2):201-221

We present a first assessment of the Sea Surface Temperature (SST) and 300m Heat Content (HC) ensemble mean skill of the Australian Community Climate and Earth-System Simulator-Seasonal v1.0 (ACCESS-S1) around New Zealand on seasonal timescales, using a set of retrospective ensemble forecasts for 1990-2012. This was verified against Reynolds AVHRR analysis and Bluelink ReANalysis 3.5 (BRAN3.5). For inshore areas with depth <300m, the model shows skill forecasting for summer at a lead time of 0 months, with 66% and 65% of model grid cells having correlation coefficients exceeding 0.6 for SST and 300m HC respectively. Regions of lower skill seem to be associated with the model representation of the complex and variable frontal systems around New Zealand, and an overly-strong response to the El Niño Southern-Oscillation (ENSO). Nevertheless, the skill of ACCESS-S1 around New Zealand suggests there is potential for the development of useful seasonal forecast products for the region.  相似文献   

Cosmopolitan urbanism - Edited by Jon Binnie, Julian Holloway, Steven Millington and Craig Young     

Quentin Stevens 《Area》2007,39(3):407-408

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