Parameter-transformation relations for traveling-wave solutions of kdv-burgers equation

 Burgers suggested that the main properties of free-turbulence in the boundless area without basic flow might be understood with the aid of the following equation, which was much simpler than those of fluid dynamics, 更多还原

Two-time scales inner solutions and motion of a geostrophic vortex

Based on the authors' previous work, in this paper the systematical analyses on the motion and the inner solutions of a geostrophic vortex have been presented by means of thematched asymptotic expansion method with multiple time scales (S/gh001/2 and α S/gh001/2) and space scales. It has been shown that the leading inner solutions to the core structure in two-time scales analyses are identified with the results in normal one-time scale analyses. The time averages of the first-order solutions on short time variable τ are the same as the first-order solutions obtained in one normal time scale analyses. The geostrophic vortex induces an oscillatory motion in addition to moving with the background flow. The period, amplitude andthe deviation from the mean trajectory depend on the core structure and the initial conditions. The velocity of the motion of vortex center varies periodically and the time average of the velocity on short time variable τ is equal to the value of the local mean velocity.

Asymptotic solutions to a class of nonlinear oscillation systems

In this paper, we present an asymptotic method for the analysis of a class of strongly nonlinear oscillators, derive second-order approximate solutions to them expressed in terms of their amplitudes and phases, and obtain the equations governing the amplitudes and phases, by which the amplitudes of the corresponding limit cycles and their behaviour can be determined. As an example, we investigate the modified van der Pol oscillator and give the second-order approximate analytical solution of its limit cycle. The comparison with the numerical solutions shows that the two results agree well with each other.

The dynamical process of a coronal transient associated with an eruptive prominence .2. Analytical solutions in finite regions

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Caribbean connectivity: implications for Marine Protected Area Management. Proceedings of a Special Symposium, 9-11 November 2006, 59th Annual Meeting of the Gulf and Caribbean Fisheries Institute, Belize City, Belize

Executive Summary: Tropical marine ecosystems in the Caribbean region are inextricably linked through the movement of pollutants, nutrients, diseases, and other stressors, which threaten to further degrade coral reef communities. The magnitude of change that is occurring within the region is considerable, and solutions will require investigating pros and cons of networks of marine protected areas (MPAs), cooperation of neighboring countries, improved understanding of how external stressors degrade local marine resources, and ameliorating those stressors. Connectivity can be broadly defined as the exchange of materials (e.g., nutrients and pollutants), organisms, and genes and can be divided into: 1) genetic or evolutionary connectivity that concerns the exchange of organisms and genes, 2) demographic connectivity, which is the exchange of individuals among local groups, and 3) oceanographic connectivity, which includes flow of materials and circulation patterns and variability that underpin much of all these exchanges. Presently, we understand little about connectivity at specific locations beyond model outputs, and yet we must manage MPAs with connectivity in mind. A key to successful MPA management is how to most effectively work with scientists to acquire the information managers need. Oceanography connectivity is poorly understood, and even less is known about the shape of the dispersal curve for most species. Dispersal kernels differ for various systems, species, and life histories and are likely highly variable in space and time. Furthermore, the implications of different dispersal kernels on population dynamics and management of species is unknown. However, small dispersal kernels are the norm - not the exception. Linking patterns of dispersal to management options is difficult given the present state of knowledge. The behavioral component of larval dispersal has a major impact on where larvae settle. Individual larval behavior and life history details are required to produce meaningful simulations of population connectivity. Biological inputs are critical determinants of dispersal outcomes beyond what can be gleaned from models of passive dispersal. There is considerable temporal and spatial variation to connectivity patterns. New models are increasingly being developed, but these must be validated to understand upstream-downstream neighborhoods, dispersal corridors, stepping stones, and source/sink dynamics. At present, models are mainly useful for providing generalities and generating hypotheses. Low-technology approaches such as drifter vials and oceanographic drogues are useful, affordable options for understanding local connectivity. The “silver bullet” approach to MPA design may not be possible for several reasons. Genetic connectivity studies reveal divergent population genetic structures despite similar larval life histories. Historical stochasticity in reproduction and/or recruitment likely has important, longlasting consequences on present day genetic structure. (PDF has 200 pages.)

First Biennial Ocean Climate Summit: Finding Solutions for San Francisco Bay Area’s Coast and Ocean. Proceedings of the Summit: April 29, 2008, Golden Gate Club, The Presidio San Francisco, California

Executive Summary: The marine environment plays a critical role in the amount of carbon dioxide (CO2) that remains within Earth’s atmosphere, but has not received as much attention as the terrestrial environment when it comes to climate change discussions, programs, and plans for action. It is now apparent that the oceans have begun to reach a state of CO2 saturation, no longer maintaining the “steady-state” carbon cycle that existed prior to the Industrial Revolution. The increasing amount of CO2 present within the oceans and the atmosphere has an effect on climate and a cascading effect on the marine environment. Potential physical effects of climate change within the marine environment, including ocean acidification, changes in wind and upwelling regimes, increasing global sea surface temperatures, and sea level rise, can lead to dramatic, fundamental changes within marine and coastal ecosystems. Altered ecosystems can result in changing coastal economies through a reduction in marine ecosystem services such as commercial fish stocks and coastal tourism. Local impacts from climate change should be a front line issue for natural resource managers, but they often feel too overwhelmed by the magnitude of this issue to begin to take action. They may not feel they have the time, funding, or staff to take on a challenge as large as climate change and continue to not act as a result. Already, natural resource managers work to balance the needs of humans and the economy with ecosystem biodiversity and resilience. Responsible decisions are made each day that consider a wide variety of stakeholders, including community members, agencies, non-profit organizations, and business/industry. The issue of climate change must be approached as a collaborative effort, one that natural resource managers can facilitate by balancing human demands with healthy ecosystem function through research and monitoring, education and outreach, and policy reform. The Scientific Expert Group on Climate Change in their 2007 report titled, “Confronting Climate Change: Avoiding the Unmanageable and Managing the Unavoidable” charged governments around the world with developing strategies to “adapt to ongoing and future changes in climate change by integrating the implications of climate change into resource management and infrastructure development”. Resource managers must make future management decisions within an uncertain and changing climate based on both physical and biological ecosystem response to climate change and human perception of and response to the issue. Climate change is the biggest threat facing any protected area today and resource managers must lead the charge in addressing this threat. (PDF has 59 pages.)

Black Holes, Cosmological Solutions, Future Singularities, and Their Thermodynamical Properties in Modified Gravity Theorie

54 p.

Dissolved oxygen probes: making oxygen measurements routine like temperature, St Petersburg, Florida, January 4-6, 2006: workshop proceedings

The Alliance for Coastal Technologies (ACT) Workshop "Making Oxygen Measurements Routine Like Temperature" was convened in St. Petersburg, Florida, January 4th - 6th, 2006. This event was sponsored by the University of South Florida (USF) College of Marine Science, an ACT partner institution and co-hosted by the Ocean Research Interactive Observatory Networks (ORION). Participants from researcldacademia, resource management, industry, and engineering sectors collaborated with the aim to foster ideas and information on how to make measuring dissolved oxygen a routine part of a coastal or open ocean observing system. Plans are in motion to develop large scale ocean observing systems as part of the US Integrated Ocean Observing System (100s; see http://ocean.us) and the NSF Ocean Observatory Initiative (001; see http://www.orionprogram.org/00I/default.hl). These systems will require biological and chemical sensors that can be deployed in large numbers, with high reliability, and for extended periods of time (years). It is also likely that the development cycle for new sensors is sufficiently long enough that completely new instruments, which operate on novel principles, cannot be developed before these complex observing systems will be deployed. The most likely path to development of robust, reliable, high endurance sensors in the near future is to move the current generation of sensors to a much greater degree of readiness. The ACT Oxygen Sensor Technology Evaluation demonstrated two important facts that are related to the need for sensors. There is a suite of commercially available sensors that can, in some circumstances, generate high quality data; however, the evaluation also showed that none of the sensors were able to generate high quality data in all circumstances for even one month time periods due to biofouling issues. Many groups are attempting to use oxygen sensors in large observing programs; however, there often seems to be limited communication between these groups and they often do not have access to sophisticated engineering resources. Instrument manufacturers also do not have sufficient resources to bring sensors, which are marketable, but of limited endurance or reliability, to a higher state of readiness. The goal of this ACT/ORION Oxygen Sensor Workshop was to bring together a group of experienced oceanographers who are now deploying oxygen sensors in extended arrays along with a core of experienced and interested academic and industrial engineers, and manufacturers. The intended direction for this workshop was for this group to exchange information accumulated through a variety of sensor deployments, examine failure mechanisms and explore a variety of potential solutions to these problems. One anticipated outcome was for there to be focused recommendations to funding agencies on development needs and potential solutions for 02 sensors. (pdf contains 19 pages)