VLBI observations of GNSS-satellites: from scheduling to analysis   总被引：1，自引：1，他引：0  

Lucia Plank  Andreas Hellerschmied  Jamie McCallum  Johannes Böhm  Jim Lovell 《Journal of Geodesy》2017,91(7):867-880

The possibility of observing satellites with the very long baseline interferometry (VLBI) technique has been discussed for several years in the geodetic community, with observations of either existing satellites of the global navigation satellite systems or of satellites dedicated to realise a space tie. Such observations were carried out using the Australian telescopes in Hobart and Ceduna which, for the first time, integrated all the necessary steps: planning the observations (automated scheduling), correlation of the data and the generation of a series of time delay observables suitable for a subsequent geodetic analysis. We report on the development of new and the adaptation of existing routines for observing and data processing, focusing on technology development. The aim was to use methods that are routinely used in geodetic VLBI. A series of test experiments of up to six hours duration was performed, allowing to improve the observations from session to session and revealing new problems still to be solved. The newly developed procedures and programs now enable more observations. Further development assumed, this bears the prospect of being directly applied to the observation of dedicated space-tie satellites.  相似文献   

The effects of acid sulphate run-off on a subtidal estuarine macrobenthic community in the Richmond River, NSW, Australia   总被引：1，自引：0，他引：1  

Corfield  Jamie 《ICES Journal of Marine Science》2000,57(5):1517-1523

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Can stable oxygen and hydrogen isotopes from Australian subfossil Chironomus head capsules be used as proxies for past temperature change?     

Jie Christine Chang  James Shulmeister  Craig Woodward  Greg Michalski 《Journal of Paleolimnology》2016,56(4):331-348

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Are we adapting to climate change? A catchment-based adaptation assessment tool for freshwater ecosystems     

Anna Lukasiewicz  Jamie Pittock  C. Max Finlayson 《Climatic change》2016,138(3-4):641-654

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Health and environmental co-benefits and conflicts of actions to meet UK carbon targets     

Alison C. Smith  Michael Holland  Outi Korkeala  Jamie Warmington  Daniel Forster  Helen ApSimon 《Climate Policy》2016,16(3):253-283

Many actions to reduce GHG emissions have wider impacts on health, the economy, and the environment, beyond their role in mitigating climate change. These ancillary impacts can be positive (co-benefits) or negative (conflicts). This article presents the first quantitative review of the wider impacts on health and the environment likely to arise from action to meet the UK's legally-binding carbon budgets. Impacts were assessed for climate measures directed at power generation, energy use in buildings, and industry, transport, and agriculture. The study considered a wide range of health and environmental impacts including air pollution, noise, the upstream impacts of fuel extraction, and the lifestyle benefits of active travel. It was not possible to quantify all impacts, but for those that were monetized the co-benefits of climate action (i.e. excluding climate benefits) significantly outweigh the negative impacts, with a net present value of more than £85 billion from 2008 to 2030. Substantial benefits arise from reduced congestion, pollution, noise, and road accidents as a result of avoided journeys. There is also a large health benefit as a result of increased exercise from walking and cycling instead of driving. Awareness of these benefits could strengthen the case for more ambitious climate mitigation action.

Policy relevance

This article demonstrates that actions to mitigate GHG emissions have significant wider benefits for health and the environment. Including these impacts in cost–benefit analysis would strengthen the case for the UK (and similar countries) to set ambitious emissions reduction targets. Understanding co-benefits and trade-offs will also improve coordination across policy areas and cut costs. In addition, co-benefits such as air quality improvements are often immediate and local, whereas climate benefits may occur on a longer timescale and mainly in a distant region, as well as being harder to demonstrate. Dissemination of the benefits, along with better anticipation of trade-offs, could therefore boost public support for climate action.  相似文献   

Progress and Challenges in Coupled Hydrodynamic-Ecological Estuarine Modeling     

Neil K. Ganju  Mark J. Brush  Brenda Rashleigh  Alfredo L. Aretxabaleta  Pilar del Barrio  Jason S. Grear  Lora A. Harris  Samuel J. Lake  Grant McCardell  James O’Donnell  David K. Ralston  Richard P. Signell  Jeremy M. Testa  Jamie M. P. Vaudrey 《Estuaries and Coasts》2016,39(2):311-332

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.  相似文献   

A clear and present danger: Ladakh's increasing vulnerability to flash floods and debris flows          下载免费PDF全文

Alan D. Ziegler  Sebastian I. Cantarero  Robert J. Wasson  Pradeep Srivastava  Sonam Spalzin  Winston T. L. Chow  Jamie Gillen 《水文研究》2016,30(22):4214-4223

This preliminary investigation of the recent spate of deadly flash floods and debris flows in Ladakh (India) over the last decade identifies uncontrolled development in hazardous locations as an important factor contributing to loss of life and property damage in this high mountain desert. The sediments exposed in the channel banks and on the alluvial fans of several mountain streams in the area indicate a long history of flash floods and debris flows resulting from intense storms, which appear to have increased in frequency within the last decade. The signposts of these recurrent hazards are being ignored as a growing economy, which is boosted by a well‐established tourism industry, is now driving development onto lands that are susceptible to floods and debris flow hazards. In this science briefing we argue that the increasing vulnerability in Ladakh should be addressed with sound disaster governance strategies that are proactive, rather than reactionary. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

The Precambrian–Cambrian nonconformity at the Ercall Quarries,The Wrekin,Shropshire, UK     

Jamie K. Pringle  Ian G. Stimpson 《Geology Today》2013,29(5):195-199

The Precambrian–Cambrian boundary is iconic, marking the first appearance of shelly fauna in the fossil record, and opening the Phanerozoic Eon. In England and Wales, the transition from predominantly Precambrian igneous rocks to Cambrian sedimentary strata is generally unconformable. An exceptional exposure of this transition can be observed in the Ercall Quarries in Shropshire, a classic locality in all senses of the word.  相似文献   

Depositional processes across the Sinú Accretionary Prism,offshore Colombia     

Jamie S. Vinnels  Robert W.H. Butler  William D. McCaffrey  Douglas A. Paton 《Marine and Petroleum Geology》2010,27(4):794-809

The Pliocene to Recent of the Sinú Accretionary Prism, offshore Colombia, features gravity current dominated basins characterised primarily by channel- and sheet-like architectures and those with dominantly hemipelagic fills. The prism is fed by rivers that drain from uplifted older basins and volcanic Andean terranes to the south and east which source large volumes of sediment to the Colombian Shelf into the Colombian Basin. Some basin fills show evidence of both localised fold-induced sediment failure and regional-scale shelf collapse, both related to the generation and destruction of oversteepened slopes. Large scale collapses can create new sediment routing pathways and/or local depocentres into which sediment subsequently accumulates. In the Colombian Basin, even relatively distal basins show evidence of channel activity related primarily to the creation of new sediment distribution pathways through breaches in the substrate barriers between basins. These channels are often orientated parallel to the regional drainage trend, suggesting that regional sediment transport trends can assert themselves relatively early in a basin filling history regardless of the local bathymetric grain. While, at a regional scale, sediment dispersal fairways reflect drainage from the continental shelf to the basin floor, intraslope basins form local bathymetric obstructions that can drive local spatial variations in sediment distribution. Thus, both local and regional length scales of bathymetric control are evident within the intraslope basins of the Sinú Accretionary Prism. Although regional dispersal patterns generally become more important in time, individual intraslope basins exhibit more complex filling histories because events such as sill or shelf collapse may serve to disrupt established distribution pathways, initiating repeated episodes of adjustment.  相似文献   

Pilgrims,progress, and the political economy of disaster preparedness – the example of the 2013 Uttarakhand flood and Kedarnath disaster          下载免费PDF全文

Alan D. Ziegler  Robert J. Wasson  Alok Bhardwaj  Y. P. Sundriyal  S. P. Sati  Navin Juyal  Vinod Nautiyal  Pradeep Srivastava  Jamie Gillen  Udisha Saklani 《水文研究》2014,28(24):5985-5990

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