摘要:

A short survey of results related to solitary internal waves in the ocean is presented. We discuss observations of solitary waves in shallow seas and deep ocean regions accumulated over the last two decades. Work containing more or less complete hydrodynamical data that allow one to construct adequate theoretical models and to compare theory with experimental results is considered in more detail. The relation between the features of observed solitary formations and those of solitons known in theory is also developed. A summary of theoretical models describing nonlinear internal wave propagation, including the basic evolution equations and their soliton solutions, is presented in an appendix.

ISSN:8755-1209    

DOI:10.1029/RG027i003p00293

年代:1989

数据来源: WILEY

摘要:

Multiphase flow and transport of compositionally complex fluids in geologic media is of importance in a number of applied problems which have major social and economic effects. In petroleum reservoir engineering, efficient recovery of energy reserves is the principal goal. Unfortunately, some of these hydrocarbons and other organic chemicals often find their way unwanted into the soils and groundwater supplies. Removal in the latter case is predicated on ensuring the public health and safety. In this paper, principles of modeling fluid flow in systems containing up to three fluid phases (namely, water, air, and organic liquid) are described. Solution of the governing equations for multiphase flow requires knowledge of functional relationships between fluid pressures, saturations, and permeabilities which may be formulated on the basis of conceptual models of fluid‐porous media interactions. Mechanisms of transport in multicomponent multiphase systems in which species may partition between phases are also described, and the governing equations are presented for the case in which local phase equilibrium may be assumed. A number of hypothetical numerical problems are presented to illustrate the physical behavior of systems in which multiphase flow and transport aris

ISSN:8755-1209    

DOI:10.1029/RG027i003p00311

年代:1989

数据来源: WILEY

摘要:

Growing atmospheric concentrations of carbon dioxide and other trace gases are leading to climatic changes with important implications for the hydrologic balance and water resources. These “greenhouse gases” are expected to alter the radiative balance of the atmosphere, causing increases in temperature and changes in many other climatic variables. Recent hydrological research strongly suggests that this so‐called “greenhouse effect” will alter the timing and magnitude of runoff and soil moisture, change lake levels, and affect water quality. Such changes raise the possibility of environmental and socioeconomic dislocations, and they have important implications for future water resources planning and management. This paper reviews state‐of‐the‐art research into the implications of climatic changes for the hydrologic cycle and for water resources and discusses the implications of such changes for future water planning

ISSN:8755-1209    

DOI:10.1029/RG027i003p00329

年代:1989

数据来源: WILEY

摘要:

Digital remotely sensed observations of the atmosphere, particularly from radars and satellites, have become increasingly available over the last 15 years. Together with developments in computer technology this has stimulated the design and operation of a variety of systems to exploit these data in weather forecasting. Growing awareness of the importance of detailed site specific weather information and forecasts from zero to a few hours ahead has led to the emergence of a particular kind of forecasting called nowcasting which depends on the exceptionally detailed knowledge of the current pattern of weather that remote sensing can provide. This type of weather forecasting is reviewed, with emphasis on the measurement and extrapolation up to about 2 hours ahead of fields of various weather parameters, especially rainfall. Trends in the design of nowcasting systems are discussed, and potential benefits summarized.

ISSN:8755-1209    

DOI:10.1029/RG027i003p00345

年代:1989

数据来源: WILEY

摘要:

During the last decade, ionosphericFregion modeling has reached an accurate climatological level. We now have global computer models of theFregion which simulate the interactions between physical processes in the ionosphere. Because of their complexity, these climatological models are confined to modern day supercomputers. This review focuses on the development and verification of these physical ionospheric models. Such models are distinct from local models, steady state models, and empirical models of the ionosphere, which are, by their conception, unable to represent physically the range ofFregion variability or storm dynamics. This review examines the limitations of the physical models, which are at the present time mainly associated with inputs to the ionospheric system. Of these, the magnetospheric electric field and auroral precipitation are by far the most dominant and yet the least well‐defined dynamic inputs. Several developments are currently under way which could well lead to meteorological modeling capabilities in the next decade. For this the use of higher‐resolution inputs, both temporal and spatial (for example, auroral imagery), is critical. Coupling the ionospheric models with thermospheric and magnetospheric models will lead to self‐consistency and probably a predictive capability. Coupling to thermospheric models is currently under way; however, coupling with the magnetosphere must await the development of a magnetospheric

ISSN:8755-1209    

DOI:10.1029/RG027i003p00371

年代:1989

数据来源: WILEY

摘要:

While a great deal of climate data have been gathered over the past hundred years, there remains a number of problems limiting our ability to fully utilize these data in reconstructing the climate of the past century. This is particularly true for research demanding high precision and/or detailed local or regional‐scale climate analyses. In this review we consider our ability to quantify climate change with respect to near‐surface air temperature (measured 1.25–2 m above ground), sea surface temperature, precipitation, snow cover, sea ice, and vegetation measured from space and the Earth's surface. Among the data issues we discuss are calibration, observing practices, urbanization, station changes, data representativeness, data access, and areal coverage. The diversity of measurements over the past century and the new monitoring system being introduced via space‐based and surface‐based platforms offer an unparalleled opportunity for global monitoring; but to quantify climate change, we must tackle such issues as changing retrieval algorithms, relatively short periods of record, satellite Earth location precision, incompatibility with previous conventional historical observations, calibration, and potentially overwhelming data volumes. A new specialty within the climate field is beginning to emerge to address these problems. Despite the litany of problems the instrumented climate record can tell us a great deal about the spatial distribution and secular trends in temperature and precipitation over many areas of the world. In the future a blend of many data types and observing systems will be necessary to better quantify climate change. These large data sets will have to be made accessible to scientists in such a way that allows them an opportunity to check the veracity of their hypotheses and predictions regarding clima

ISSN:8755-1209    

DOI:10.1029/RG027i003p00405

年代:1989

数据来源: WILEY