Shallow bathymetry is important for ocean exploration, and the development of high-precision inversion methods, especially shallow waters with poor quality, a major research aim. Synthetic aperture radar (SAR) image data benefit from wide coverage, high measurement density, rapidity, low consumption but are limited by accuracy. Alternatively, multibeam have coverage difficult to obtain In this ...

National Oceanic and Atmospheric Administration’s National Ocean Service uses observations, hydrodynamic models and interpolation techniques to develop many of its products and services. We examine how two projects, computation of tidal datums for vertical datum transformation and the estimation of tidal characteristics for hydrographic surveys, are being developed in Alaska and how they may be...

This thesis studies the role of cross-isopycnal mixing in general circulation dynamics , from both the theoretical and observational points of view. The first two chapters discuss some theoretical aspects of cross-isopycnal mixing in the oceans. In chapter one, an integral constraint relating the interior stratification and air-sea heat fluxes is derived, based on the condition that the total m...

Introduction: The U.S. Geological Survey’s (USGS) Center of Excellence in Geospatial Information Science (CEGIS) is conducting generalization research in cooperation with the University of Colorado—Boulder and Pennsylvania State University to support display and delivery of The National Map and other USGS geospatial data at multiple scales. This paper focuses on generalization of the National H...

Quanti-qualitative changes in Dinophysis and Alexatidrium populations from the Gulf of Venice NW Adriatic Sea were studied on a short time scale (44 h cycles). Under hydrographic conditions of marked thermo-haline stratification (July 1995), D. sacculus populations assembled in the surface waters (12 24 yt isopycnals). Division processes took place mostly in the early hours of the morning and a...

The water louse Asellus aquaticus is a widespread, euryoecious species, mostly uniform throughout its range. However, six subspecies are known from the Dinaric karst in the northwestern Balkans. They include some specialized subterranean populations. The pattern of genetic variation among subterranean and surface populations in this hydrographically highly fragmented karst region was investigat...

This paper presents a two-layer network for extracting hydrographic objects, such as rivers, from satellite images. The first layer is a locally connected network, which per$orms nonlinear smoothing. A unique property of the network is that boundaries and junctions are preserved with high accuracy while noise within each region is greatly suppressed. A second layer is a locally excitatory globa...

Many marine protists form resting stages that can remain viable in coastal sediments for several decades. Their long-term survival offers the possibility to explore the impact of changes in environmental conditions on population dynamics over multidecadal time scales. Resting stages of the phototrophic dinoflagellate Pentapharsodinium dalei were isolated and germinated from five layers in dated...