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   

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   

Comments on “The significance of coral reefs as global carbon sinks—response to greenhouse” by D.W. Kinsey and D. Hopley     

Stuart R Gaffin  Rodney M Fujita 《Global and Planetary Change》1992,5(4)

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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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珠江三角洲沉积物的岩石磁学性质及其环境意义   总被引：1，自引：0，他引：1  

杨小强  Rodney Grapes  周厚云  阳杰 《中国科学D辑》2007,37(11):1493-1503

选取珠江三角洲区域位于广州番禺的PD钻孔进行沉积物岩石磁学和环境磁学记录的研究. 岩石磁学实验表明钻孔大部分沉积物以低矫顽力的磁铁矿类矿物为主要控磁矿物, 但仍存在少量铁硫化物. 在有机质丰富的灰黑色黏土沉积中, 铁硫化物含量增加, 成为影响沉积物磁性特征的主要矿物, 标志着海退后富含有机质而缺氧的沼泽环境. 以赤铁矿和针铁矿类矿物为主要控磁矿物的花斑黏土, 表明了一个较长时期的暴露风化过程, 代表着沉积间断. 在以磁铁矿类矿物作为主要载磁矿物的沉积物中, 磁铁矿浓度及粒度的变化主导磁化率(κ)、饱和等温剩磁(SIRM)等环境磁学参数的变化, SIRM/κ 和χ_arm/SIRM的大小旋回响应于海平面的升-降过程, 它们的高值反映了磁性矿物粒度变细、海平面上升. 在沉积学分析的基础上, 根据环境磁学参数截然不同的变化规律, 结合微体古生物数据, 将珠江三角洲沉积物代表的环境分为两次显著的海平面上升－下降旋回, 晚更新世和全新世的海侵又包含若干个比较明显的次级海平面波动过程.  相似文献   

Study of near-surface models for large-eddy simulations of a neutrally stratified atmospheric boundary layer     

Inanc Senocak  Andrew S. Ackerman  Michael P. Kirkpatrick  David E. Stevens  Nagi N. Mansour 《Boundary-Layer Meteorology》2007,124(3):405-424

In large-eddy simulations (LES) of the atmospheric boundary layer (ABL), near-surface models are often used to supplement subgrid-scale (SGS) turbulent stresses when a major fraction of the energetic scales within the surface layer cannot be resolved with the temporal and spatial resolution at hand. In this study, we investigate the performance of both dynamic and non-dynamic eddy viscosity models coupled with near-surface models in simulations of a neutrally stratified ABL. Two near-surface models that are commonly used in LES of the atmospheric boundary layer are considered. Additionally, a hybrid Reynolds- averaged/LES eddy viscosity model is presented, which uses Prandtl’s mixing length model in the vicinity of the surface, and blends in with the dynamic Smagorinsky model away from the surface. Present simulations show that significant portions of the modelled turbulent stresses are generated by the near-surface models, and they play a dominant role in capturing the expected logarithmic wind profile. Visualizations of the instantaneous vorticity field reveal that flow structures in the vicinity of the surface depend on the choice of the near-surface model. Among the three near-surface models studied, the hybrid eddy viscosity model gives the closest agreement with the logarithmic wind profile in the surface layer. It is also observed that high levels of resolved turbulence stresses can be maintained with the so-called canopy stress model while producing good agreement with the logarithmic wind profile.  相似文献   

Deep radio imaging of the SCUBA 8-mJy survey fields: submillimetre source identifications and redshift distribution     

R. J. Ivison  T. R. Greve  Ian Smail  J. S. Dunlop  N. D. Roche  S. E. Scott  M. J. Page  J. A. Stevens  O. Almaini  A. W. Blain  C. J. Willott  M. J. Fox  D. G. Gilbank  S. Serjeant  D. H. Hughes 《Monthly notices of the Royal Astronomical Society》2002,337(1):1-25

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Progress in NTHMP Hazard Assessment     

Frank I. González  Vasily V. Titov  Harold O. Mofjeld  Angie J. Venturato  R. Scott Simmons  Roger Hansen  Rodney Combellick  Richard K. Eisner  Don F. Hoirup  Brian S. Yanagi  Sterling Yong  Mark Darienzo  George R. Priest  George L. Crawford  Timothy J. Walsh 《Natural Hazards》2005,35(1):89-110

The Hazard Assessment component of the U.S. National Tsunami Hazard Mitigation Program has completed 22 modeling efforts covering 113 coastal communities with an estimated population of 1.2 million residents that are at risk. Twenty-three evacuation maps have also been completed. Important improvements in organizational structure have been made with the addition of two State geotechnical agency representatives to Steering Group membership, and progress has been made on other improvements suggested by program reviewers.  相似文献   

Chandra and XMM–Newton observations of NGC 4214: the hot interstellar medium and the luminosity function of dwarf starbursts     

Joanna M. Hartwell  Ian R. Stevens  David K. Strickland †  Timothy M. Heckman  Lesley K. Summers 《Monthly notices of the Royal Astronomical Society》2004,348(2):406-420

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