A New Leak Detection System for Long-Distance Pipelines Utilizing Soil-Gas Techniques     

K.F. Liang  M.C. Tom Kuo 《Ground Water Monitoring & Remediation》2006,26(3):53-59

  相似文献   

GPS/GNSS Current Bibliography     

Tomás Soler 《GPS Solutions》2006,10(1):63-66

  相似文献   

On the physics of the Atlantic Multidecadal Oscillation   总被引：1，自引：0，他引：1  

Henk A. Dijkstra  Lianke te Raa  Maurice Schmeits  Jeroen Gerrits 《Ocean Dynamics》2006,56(1):36-50

The Atlantic Multidecadal Oscillation (AMO) is a pronounced signal of climate variability in the North Atlantic sea-surface temperature field. In this paper, we propose an explanation of the physical processes responsible for the timescale and the spatial pattern of the AMO. Our approach involves the analysis of solutions of a hierarchy of models. In the lowest member of the model hierarchy, which is an ocean-only model for flow in an idealized basin, the variability shows up as a multidecadal oscillatory mode which is able to destabilize the mean thermohaline circulation. In the highest member of the model hierarchy, which is the Geophysical Fluid Dynamics Laboratory R30 climate model, multidecadal variability is found as a dominant statistical mode of variability. The connection between both results is established by tracing the spatial and temporal expression of the multidecadal mode through the model hierarchy while monitoring changes in specific quantities (mechanistic indicators) associated with its physics. The proposed explanation of the properties of the AMO is eventually based on the changes in the spatial patterns of variability through the model hierarchy.Responsible Editor: Tal Ezer  相似文献   

The Natural Hazards Theme of the International Year of Planet Earth     

Tom Beer 《Natural Hazards》2007,42(3):469-480

The United Nations has declared 2008 to be the International Year of Planet Earth. It is being organised under the auspices of the International Union of Geological Sciences and UNESCO. Planning for the International Year of Planet Earth has consisted of establishing 10 major science themes including Hazards. The Hazards Theme is centred around the following key questions: (1) How have humans altered the geosphere, the biosphere and the landscape, thereby creating long-term changes detrimental to life and the environment and triggering certain hazards, while increasing societal vulnerability to geophysical (geological and hydrometeorological) hazards? (2) What technologies and methodologies are required to assess the vulnerability of people and places to hazards and how might these be used at a variety of spatial scales? (3) How do geophysical hazards compare relative to each other regarding current capabilities for monitoring, prediction and mitigation and what can be done in the short-term to improve these capabilities (4) What barriers exist to the utilisation of risk and vulnerability information by governments (and other entities) for risk and vulnerability reduction policies and planning (including mitigation) from each of the geophysical hazards? Following the 26 December 2004 Indian Ocean Tsunami and the UN World Conference on Disaster Reduction held in Kobe, Japan in January 2005, the International Council for Science (ICSU) decided to establish a major research programme and initiative on Natural and Human Induced Environmental Hazards and Disasters that will co-operate with the Hazards theme of the International Year and continue through to 2011.  相似文献   

Detection of iodine monoxide radicals in the marine boundary layer using laser induced fluorescence spectroscopy     

Lisa K. Whalley  Kate L. Furneaux  Tom Gravestock  Helen M. Atkinson  Catherine S. E. Bale  Trevor Ingham  William J. Bloss  Dwayne E. Heard 《Journal of Atmospheric Chemistry》2007,58(1):19-39

A Laser Induced Fluorescence (LIF) instrument has been developed to detect iodine monoxide (IO) radicals in the atmosphere. An all solid-state Nd:YAG pumped Ti:Sapphire laser operating at approximately 445 nm was used to excite the (2,0) band of the IO A²Π_3/2 ← X²Π_3/2 electronic transition, with off-resonance fluorescence in the (2,5) band detected at 521 nm. The sensitivity of the instrument was determined by calibration. IO (between 10 and 150 pptV) was generated following the 184.9 nm photolysis of N₂O/CF₃I/N₂ mixtures with O₃ actinometry used to determine the photolysis flux. The detection limit was determined to be 0.3 pptV for a 300 s integration period, with an uncertainty of 23% (1σ). The instrument was deployed in August/September 2006 during the RHaMBLe (Reactive Halogens in the Marine Boundary Layer) campaign in Roscoff, France. Located on a small jetty, a few metres from the water’s edge at high tide, the instrument measured significant levels of IO on 11 days, with a maximum of 27.6 ± 3.2 pptV observed on one day (averaged over 10 s) representing the highest IO mixing ratio recorded in the marine boundary layer to date. IO displayed a clear diurnal profile with a maximum at low tide during the daytime. These results represent the first point measurements of IO in the atmosphere by LIF.  相似文献   

GPS & GLONASS Current Bibiography     

Tomás Soler 《GPS Solutions》1998,2(2):69-71

  相似文献   

Global geopolitical change and the Asia-Pacific: a regional perspective, Edited by Dennis Rumley, Tatsuya Chiba, Akihiko Takagi and Yoriko Fukushima.     

Tom Nierop 《GeoJournal》1998,45(3):235-237

  相似文献   

A Method for Installing Piezometers in Large Cobble Bed Rivers     

David R. Geist  Mark C. Joy  David R. Lee  Tom Gonser 《Ground Water Monitoring & Remediation》1998,18(1):78-82

An impact drive point method is described for emplacing piezometers in a cobble river bottom where this has previously been difficult without the use of drilling rigs. To force the drive point piezometers through coble, the vibrational impact of an air-powered hammer was carried directly to the drive point by the use of an internal drive rod. After insertion to depth, the drive rod was removed from the lower portion of the piezometer and a standpipe was added to extend the piezometer above the river level. Piezometers installed in this way have permitted water quality analysis and dynamic measurement of vertical potentials in cobble sediments ranging in size from 2.5 to >30 cm and the method has been successfully used in the Columbia River, USA, and Töss River, Switzerland. This innovative method provides information on the hydrodynamics of pore water in highly permeable, cobble deposits that are common in high-energy river and lake bottoms. Piezometers installed using the internal drive rod method facilitate the assessment of the temporal and spatial dynamics of recharge and discharge at the ground water/surface water interface and analyses of the ecological connectivity between the hyporheic zone and surface water of rivers and streams. This information will lead to improved management decisions related to our nation's ground water and surface water supplies.  相似文献   

A comment on determining the induced magnetic field in bodies of arbitrary shape     

Josef Bochníček  Tomáš Zelinka  Reviewer T. Kolbenheyer 《Studia Geophysica et Geodaetica》1981,25(4):411-412

Summary The authors prove that the solution of Laplace's equation under Neumann's boundary conditions can be transformed to an advantage into determining the field which is generated by charges, induced by the external field at surfaces of discontinuity.  相似文献   

Physical geology: Principles,processes, and problems,C. J. Cazaeu,R. D. Hatcher and F. T. Siemankowski,Harper & Row,Publishers, 1976. Price: $11.20     

Tom Dunne 《地球表面变化过程与地形》1978,3(4):427-427

  相似文献