Recent decades have seen a degradation of the environmental quality in semi-enclosed seas, which are particularly sensitive to population pressures due to their naturally low flushing rates related to their geometry. The North Sea, Baltic Sea and the Black Sea are amongst the most seriously threatened seas in the Euro-Asian region. Each semi-enclosed sea has a distinct pattern of circulation, transport, mixing, associated with the particular geometry, topography, boundary processes, interior stratification, atmospheric forcing, ice fonnation, straits / sill controls, and the specific inputs of freshwater, nutrients and pollutants. The workshop investigated the distinctive physical and ecological characteristics of the three seas in a comparative manner, in order to identify the types of driving forces and dynamic controls operating on productivity, nutrient cycling, physical transport and mixing mechanisms. A comparative study of these controlling mechanisms would allow us to better understand ecosystem sensitivity in these different environments. The workshop presentations highlighted the complexity of the semi-enclosed seas related to the interaction amongst the physical, chemical and biological fields, and differences in time and space scales in each of the systems. Further, a strong climate signal exists in these systems, manifest in the interannual, interdecadal and longer term variability. Part of the variability appears connected with background climatic variability.

Optical remote sensing is of invaluable help in understanding the marine environment and its biogeochemical and physical processes. The Coastal Zone Color Scanner (CZCS), which operated on board the Nimbus-7 satellite from late 1978 to early 1986, has been the main source of ocean colour data. Much work has been devoted to CZCS data processing and analysis techniques throughout the 1980s. After a decade of experience, the Productivity of the Global Ocean (PGO) Activity - which was established in the framework of the International Space Year 1992 (ISY '92) by SAFISY, the Space Agency Forum of ISY - sponsored a workshop aimed at providing a reference in ocean colour science and at promoting the full exploitation of the CZCS historical data in the field of biological oceanography. The present volume comprises a series of state-of-the-art contributions on theory, applications and future perspectives of ocean colour. After an introduction on the historical perspective of ocean colour, a number of articles are devoted to the CZCS theoretical background, on radiative transfer and in-water topics, as well as on calibration, atmospheric correction and pigment concentration retrieval algorithms developed for the CZCS. Further, a review is given of major applications of CZCS data around the world, carried out in the past decade. The following part of the book is centered on the application of ocean colour to the assessment of marine biological information, with particular regard to plankton biomass, primary productivity and the coupling of physical/biological models. The links between global oceanic production and climate dynamics are also addressed. Finally, the last section is devoted to future approaches and goals of ocean colour science, and to planned sensors and systems. The book is required reading for those involved in ocean colour and related disciplines, providing an overview of the current status in this field as well as stimulating the debate on new ideas and developments for upcoming ocean colour missions.

Thisvolumecontainsacollectionofpapersbyinternationalexpertsingeoph- ical ?uid dynamics, based upon presentations at a colloquium held in memory of Pedro Ripa on the ?rst anniversary of his untimely death. They review or present recent developments in hydrodynamic stability theory, Hamiltonian ?uid mechanics, balanceddynamics, waves, vortices, generaloceanographyand the physical oceanography of the Gulf ofCalifornia; all of them subjects in which Professor Ripamadeimportant contributions. His work, but also his friendly spiritandkindnesswerehighly regardedandappreciatedby colleagues and students alike around the world. This book is a tribute to his scienti?c legacy and constitutes a valuable reference for researchers and graduate s- dents interested in geophysical and general ?uid mechanics. Earlyin his career asa physicaloceanographer, Pedro Ripa made two la- mark contributions to geophysical ?uid dynamics. In 1981, he showed that the conservation of the potential vorticity is related to the invariance of the eq- tions of motion under the symmetry transformationsof the labels that identify the ?uid particles. That is, potential vorticity conservation is a consequence, via Noether's theorem, of the particle re-labelling symmetry. Two years later he published a paper entitled "General stability conditions for zonal ?ows in a one-layer model on the beta-plane or the sphere," where he established nec- sary conditions for stability in the shallow water equations, nowadays known as "Ripa's Theorem. " This is one of the very few Arnol'd-like stability con- tions that goes beyond two-dimensional or quasi-geostrophic ?ow, and stands alongside other famous stability criteria in making the foundations of the ?eld.

The Arctic sea ice is characterized by profound changes caused by surface melting processes and the formation of melt ponds in summer. Melt ponds contribute to the ice-albedo feedback as they reduce the surface albedo of sea ice, and hence accelerate the decay of Arctic sea ice. To quantify the melting of the entire Arctic sea ice, satellite based observations are necessary. Due to different spectral properties of snow, ice, and water, theoretically, multi-spectral optical sensors are necessary for the analysis of these distinct surface types. This study demonstrates the potential of optical sensors to detect melt ponds on Arctic sea ice. For the first time, an Arctic-wide, multi-annual melt pond data set for the years 2000-2011 has been created and analyzed.

Fifteen years ago NATO organised a conference entitled 'Ocean Acoustic Modelling'. Many of its participants were again present at this variability workshop. One such participant. in concluding his 1975 paper, quoted the following from a 1972 literature survey: ' ... history presents a sad lack of communications between acousticians and oceanographers' Have we done any better in the last 15 years? We believe so, but only moderately. There is still a massive underdeveloped potential for acousticians and oceanographers to make significant progress together. Currently, the two camps talk together insufficiently even to avoid simple misun derstandings. such as those in Table 1. Table 1 Ocsanographic and acoustic jargon (from an idea by Pol/ardi Jargon Oceanographic use Acoustic use dbordB decibar (depth in m) decibel (energy level) PE primitive equations parabolic equations convergence zone converging currents converging rays (downwelling water) (high energy density) front thermohaline front wave, ray or time front speed water current speed sound propagation speed 1 The list goes on.

Carbon dioxide and other `greenhouse' gases are increasing in the atmosphere due to the burning of fossil fuels, the destruction of rain forests, etc., leading to predictions of a gradual global warming which will perturb the global biosphere. An important process which counters this trend toward potential climate change is the removal of carbon dioxide from the surface ocean by photosynthesis. This process packages carbon in phytoplankton which enter the food chain or sink into the deep sea. Their ultimate fate is a `rain' of organic debris out of the surface-mixed layer of the ocean. On a global scale, the mechanisms and overall rate of this process are poorly known. The authors of the 25 papers in this volume present their state-of-the-art approaches to quantifying the mechanisms by which the `rain' of biogenic debris nourishes deep ocean life. Prominent deep sea ecologists, geochemists and modelers address relationships between data and models of carbon fluxes and food chains in the deep ocean. An attempt is made to estimate the fate of carbon in the deep sea on a global scale by summing up the utilization of organic matter among all the populations of the abyssal biosphere. Comparisons are made between these ecological approaches and estimates of geochemical fluxes based on sediment trapping, one-dimensional geochemical models and horizontal (physical) input from continental margins. Planning interdisciplinary enterprises between geochemists and ecologists, including new field programs, are summarized in the final chapter. The summary includes a list of the important gaps in understanding which must be addressed before the role of the deep-sea biota in global-scale processes can be put in perspective.

This symposium continues a long tradition for IUGGjIUTAM symposia going back to "Fundamental Problems in Thrbulence and their Relation to Geophysics" Marseille, 1961. The five topics that were emphasized were: turbulence modeling, statistics of small scales and coherent structures, con vective turbulence, stratified turbulence, and historical developments. The objective was to consider the ubiquitous nature of turbulence in a variety of geophysical problems and related flows. Some history of the contribu tions of NCAR and its alumni were discussed, including those of Jackson R Herring, who has been a central figure at NCAR since 1972. To the original topics we added rotation, which appeared in many places. This includes rotating stratified turbulence, rotating convective turbulence, horizontal rotation that appears in flows over terrain and the role of small scale vorticity in many flows. These complicated flows have recently begun to be simulated by several groups from around the world and this meeting provided them with an excellent forum for exchanging results, plus inter actions with those doing more fundamental work on rotating stratified and convective flows. New work on double diffusive convection was given in two presentations. The history of Large Eddy Simulations was presented and several new approaches to this field were given. This meeting also spawned some interesting interactions between observational side and how to inter pret the observations with modeling and simulations around the theme of particle dispersion in these flows.

Lake Mendota has often been called "the most studied lake in the world. " Beginning in the "classic" period of limnology in the late 19th century and continuing through the present time, this lake has been the subject of a wide variety of studies. Although many of these studies have been published in accessible journals, a significant number have appeared in local monographs and reports, ephemeral documents, or poorly distributed journals. To date, there has been no attempt at a synthetic treatment ofthe vast amount of work that has been published. One intent of the present book is to present a com prehensive compilation of the major early studies on Lake Mendota and to examine how they impinge on important present-day biological questions. In addition, this book presents a summary of field and laboratory work carried out in my own laboratory over a period of about 6 years and shows where correlations with earlier work exist. The book should be ofinterest to limnologists desiring a ready reference to data and published papers on this important lake, to biogeochemists, ocean ographers, and low-temperature geochemists interested in lakes as model sys tems for global processes, and to lake managers interested in understanding short-term and long-term changes in lake systems. Although the major thrust ofthe present book is ecologicaland environmental, sufficient background has been presented on other aspects ofLake Mendota's limnology so that the book should also be useful to nonbiologists."

Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

Oceanographic discontinuities (e. g. frontal systems, upwelling areas, ice edges) are often areas of enhanced biological productivity. Considerable research on the physics and biology of the physical boundaries defining these discontinues has been accomplished (see [I D. The interface between water and sediment is the largest physical boundary in the ocean, but has not received a proportionate degree of attention. The purpose of the Nato Advanced Research Workshop (ARW) was to focus on soft-sediment systems by identifying deficiencies in our knowledge of these systems and defining key issues in the management of coastal sedimentary habitats. Marine sediments play important roles in the marine ecosystem and the biosphere. They provide food and habitat for many marine organisms, some of which are commercially important. More importantly from a global perspective, marine sediments also provide "ecosystem goods and services" [2J. Organic matter from primary production in the water column and contaminants scavenged by particles accumulate in sediments where their fate is determined by sediment processes such as bioturbation and biogeochemical cycling. Nutrients are regenerated and contaminants degraded in sediments. Under some conditions, carbon accumulates in coastal and shelf sediments and may by removed from the carbon cycle for millions of years, having a potentially significant impact on global climate change. Sediments also protect coasts. The economic value of services provided by coastal areas has recently been estimated to be on the order of $12,568 9 10 y" [3J, far in excess of the global GNP.

The authors explain the rewarding results from the interdisciplinary collaboration between an environmental study group working on coastal ecosystems and effects of oil spills and applied mathematicians modelling wave motion on sandy beaches. By using the unified Navier-Stokes equations with a Bingham fluid model for spilled oil, multi-phase flow analysis were made. Decomposition of spilled oil by bacteria was simulated as a chemical reaction, and the theoretical and numerical analysis suggested a countermeasure to help reduce stress on coastal ecosystems. The new understanding of how ecosystems both depend upon, and help to determine, the nature of the shoreline demonstrates promising ways to better assist and exploit the regenerative powers inherent in nature.

Global warming, melting polar caps, rising sea levels and intensifying wave-current action, factors responsible for the alarming phenomena of coastal erosion on the one hand and adverse environmental impacts and the high cost of 'hard' protection schemes, on the other, have created interest in the detailed examination of the potential and range of applicability of the emerging and promising category of 'soft' shore protection methods. 'Soft' methods such as beach nourishment, submerged breakwaters, artificial reefs, gravity drain systems, floating breakwaters, plantations of hydrophylous shrubs or even dry branches, applied mostly during the past 20 years, are recognised as possessing technical, environmental and financial advantageous properties deserving more attention and further developmental experimentation than has occured hitherto. On the other hand, 'hard' shore protection methods such as seawalls, groins and detached breakwaters, artefacts borrowed from port design and construction technology, no matter how well designed and well implemented they may be, can hardly avoid intensification of the consequential erosive, often devastating, effects on the down-drift shores. Moreover, they often do not constitute environmentally and financially attractive solutions for long stretches of eroding shoreline. Engineers and scientists practising design and implementation of shore defence schemes have been aware for many years of the public demand for improved shore protection technologies. They are encouraging efforts that promise enrichment of those environmentally sound and financially attractive methods that can be safely applied.

High Performance Computing in the Geosciences surveys the state of the art of programs presently being developed which require high performance computing for their implementation, provides a guide for decision making in regard to computing directions in future numerical models, and provides an overview of future developments in massively parallel processing and their implications for numerical modelling in the geosciences.

In the framework of the Diderot Mathematical Forum (DMF) of the European Mathematical Society (EMS), December 19-20, 1997, a Videoconference was held linking three teams of specialists in Amsterdam, Madrid and Venice respectively. The general subject of this videoconference, the second one of the DMF series, was Mathematics and Environment and more specifically, Problems related to Water.

This volume contains the texts of the Madrid site contributions with important, new and unpublished, examples on the modeling, mathematical and numerical analysis and treatment of the associated control problems of relevant questions arising in Oceanography and Environment.

To place this book in perspective it is useful for the reader to be aware of the recent history of the topic of underwater sound generation at the ocean surface by natural mechanisms. A meeting in Lerici, Italy in 1987 was convened within the NATO Advanced Research Workshop series, to bring together underwater acousticians and ocean hydrodynamicists to examine various mechanisms which generate sound naturally at the ocean surface. A record of that meeting was published in the NATO scientific publication series in 1988 under the title 'Sea Surface Sound'. That meeting was successful in inspiring and co ordinating both participants and non-attending colleagues to examine some key issues which were raised during the course of presentations and discussions. The understanding among those present was that another meeting should be convened 3 years hence to report and review progress in the subject. Accordingly the second conference was convened in Cambridge in 1990, whose proceedings are presented here. This volume represents a very gratifying increase in only a 3 year interval in our understanding of a number of physical processes which generate sound at the peripheries of oceans. In fact it represents both the acceleration of singular effort as well as the development of interdisciplinary sophistication and co-operation. The enthusiasm, goodwill, and intense scientific curiosity which characterized the Lerici meeting carried through to Cambridge. The collegial atmosphere established by the participants was perfectly timed to foster another major advance in studies of ocean surface sound.

Studies of convection in geophysical flows constitute an advanced and rapidly developing area of research that is relevant to problems of the natural environment. During the last decade, significant progress has been achieved in the field as a result of both experimental studies and numerical modelling. This led to the principal revision of the widely held view on buoyancy-driven turbulent flows comprising an organised mean component with superimposed chaotic turbulence. An intermediate type of motion, represented by coherent structures, has been found to play a key role in geophysical boundary layers and in larger scale atmospheric and hydrospheric circulations driven by buoyant forcing. New aspects of the interaction between convective motions and rotation have recently been discovered and investigated. Extensive experimental data have also been collected on the role of convection in cloud dynamics and microphysics. New theoretical concepts and approaches have been outlined regarding scaling and parameterization of physical processes in buoyancy-driven geophysical flows. The book summarizes interdisciplinary studies of buoyancy effects in different media (atmosphere and hydrosphere) over a wide range of scales (small scale phenomena in unstably stratified and convectively mixed layers to deep convection in the atmosphere and ocean), by different research methods (field measurements, laboratory simulations, numerical modelling), and within a variety of application areas (dispersion of pollutants, weather forecasting, hazardous phenomena associated with buoyant forcing).

Acoustic Signal Processing for Ocean Explortion has two major goals: (i) to present signal processing algorithms that take into account the models of acoustic propagation in the ocean and; (ii) to give a perspective of the broad set of techniques, problems, and applications arising in ocean exploration. The book discusses related issues and problems focused in model based acoustic signal processing methods. Besides addressing the problem of the propagation of acoustics in the ocean, it presents relevant acoustic signal processing methods like matched field processing, array processing, and localization and detection techniques. These more traditional contexts are herein enlarged to include imaging and mapping, and new signal representation models like time/frequency and wavelet transforms. Several applied aspects of these topics, such as the application of acoustics to fisheries, sea floor swath mapping by swath bathymetry and side scan sonar, autonomous underwater vehicles and communications in underwater are also considered.

This collection of 52 papers presents the state-of-the-art of Oceanology of China Seas, including Yellow Sea, East China Sea and South China Sea. The papers are published in two volumes comprising six parts: Volume 1: Physical Oceanography, Marine Chemistry and Marine Biology. Volume 2: Marine Geology, Coastal Research and Marine Physics and Technology. The purpose of this book is to introduce to the world the most representative research of Chinese oceanographers and provide marine developers with a significant reference work. For marine scientists and developers at oceanographic institutions, academia and naval research establishments. It will also be of value to the oil company geologist having an interest in the exploration of China Seas.

This volume is one outcome of the 6th International Conference on Paleoceano graphy (ICP VI). The conference was held August 23-28, 1998 in Lisbon, Portugal. The meeting followed the traditional format of a small number of invited oral presentations complemented by a large number ofcontributed posters. Over 550 participants attended, representing thirty countries and nearly 450 posters were presented. The invited speakers addressed the main themes of the 5oral sessions. The session topics were: Polar-Tropical and Interhemisphere Linkages; Does the Ocean Cause, or Respond to, Abrupt Climatic Changes?; Biotic Responses to Major Paleoceanographic Changes; Past Warm Climates; and Innovations In Monitoring Ocean History. This is the first time in ICP history that the Conference Proceedings are published. The aim of the organisers with the publication of this book is two-fold: to provide a useful review of the field and to document the ideas/controversies raised during the con ference that may stimulate future work. The book reflects the initial intentions of the conference, but it is not a conven tional conference proceedings, given that the papers have been reviewed by formal exter nal referees. Each of the conference topics is introduced by a review article designed to summarize the state of the art in each theme followed by articles prepared by the invited speakers. As with most conference proceedings, each theme is covered heterogenously. Some topics have all the expected contributions, others are less well covered."

The Fourteenth International Tsunami Symposium held from 31 July to 3 August 1989 in Novosibirsk, U.S.S.R., was sponsored by the International Union of Geodesy and Geophysics. Sixty-five scientists from 13 countries met to exchange information on recent advances in tsunami research. The Symposium was a great success due to the enthusiasm of the participants, the quality of research presented, and the great organization provided by the Soviet hosts. Teams of dedicated workers, under the fine leadership of Academician A. S. Alexseev and Dr V. K. Gusiakov, blended social and scientific activities in a memorable fashion. The 62 presentations of the Symposium were divided into six areas of research: generation (7), propagation (12), coastal effects (10), observations (11), seismics and tectonics (10), and hazard mitigation (12). A summary of the research presented appears as the first article in this special issue. Following the Symposium, a team of session chairmen nominated 20 of these oral presentations to be published in a special issue devoted to the International Tsunami Symposium.

The future of the Common Fisheries Policy depends on progress in the relevant areas of research. This applies to the whole range of management decisions, where precise, reliable and complete data are essential to inform those who must decide on the pursuit of existing activities, especially in the area of maritime fisheries, and the development of promising new activities such as aquaculture. Every day the Director-General of DG XIV requires more and more information to prepare decisions which will affect the future of all those in the Community who are dependent on fishing and aquaculture. There is thus a high level of direct demand from DG XIV. Over and above this immediate and specific requirement for short- and medium-term applications, research affects the competitivity of the Community. This is one area which favours the collaboration across frontiers of all those who seek to advance knowledge. But although DG XIV is uniquely placed to appreciate the importance of research into fisheries and aquaculture, there is no question of succumbing to the temptation to directly control the scope of research or its conduct. The notion of subsidiarity can best be understood by examining the existing structures in the Member States. The Commission must act first and foremost as a catalyst, by promoting the circulation of information and the coordination of research programmes.

Challenging problems involvrllg jet and plume phenomena are common to many areas of fundamental and applied scientific research, and an understanding of plume and jet behaviour is essential in many geophysical and industrial contexts. For example, in the field of meteorology, where pollutant dispersal takes place by means of atmospheric jets and plumes formed either naturally under conditions of convectively-driven flow in the atmospheric boundary layer, or anthropogenically by the release of pollutants from tall chimneys. In other fields of geophysics, buoyant plumes and jets are known to play important roles in oceanic mixing processes, both at the relatively large scale (as in deep water formation by convective sinking) and at the relatively small scale (as with plume formation beneath ice leads, for example). In the industrial context, the performances of many engineering systems are determined primarily by the behaviour of buoyant plumes and jets. For example, (i) in sea outfalls, where either sewage or thermal effluents are discharged into marine and/or freshwater environments, (ii) in solar ponds, where buoyant jets are released under density interfaces, (iii) in buildings, where thermally-generated plumes affect the air quality and ventilation properties of architectural environments, (iv) in rotating machinery where fluid jet~ are used for cooling purposes, and (v) in long road and rail tunnels, where safety and ventilation prcedures rely upon an understanding of the behaviour of buoyant jets. In many other engineering and oceanographic contexts, the properties of jets and plumes are of great importance.

This Brief deals with the reconstruction of Holocene paleoenvironment in the central part of Bangladesh in relation to relative sea-level (RSL) changes which is 200 km north from the present coastline. Lithofacies characteristics, mangal peat, diatom and paleophysiographical evidences were considered to reconstruct the past position and C-14 ages were used to determine the time of formation of the relative sea-level during the Holocene. With standard reference datum the required m.s.l. at the surface of five sections are calculate and the RSL curve suggests that Bangladesh has experienced two mid Holocene RSL transgressions punctuated by regressions. The abundant marine diatom and mangrove pollens indicates that the highest RSL transgression in Bangladesh is around 6000 cal BP which is attained at least 4.5 to 5m higher than the modern m.s.l. After this phase, the relative sea-level started to fall and consequently a freshwater peat developed around 5980 5700 cal BP. The abundant mangrove pollens in salt-marsh succession shows the regression around 5500 cal BP and, the height was 1 2 m higher than the modern sea level. These and more interesting findings are discussed in this Brief.

In Chapter 1 the methodological principles of systemization and visualization of multidimensional ecological information for its operational dissemination among potential users are stated. Their realization results in creation of the geographic-and ecologic model of marine basin as an information base for diagnosis of the marine ecosystem state, estimation of consequences of economic activity, and modelling of its changes with the use of mathematical tools. In Chapter 2 the geographic-and-ecological aspects of mathematical modelling of marine ecosystems, the possibilities and peculiarities of the most adequate models, the Russian hydrodynamic model of oil spills "SPILLMOD" and hydroecological model of organogenic compound transformation in the sea, are investigated. In the following six Chapters the examples of practical realization of geographic-and-ecological (as information source) and mathematical (as computing apparatus) modelling at the investigations of specific ecological problems associated with consequences of natural hazards and economic activity on aquatory and within the whole Black Sea basin are given.

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