National Ocean Service

About: National Ocean Service is a government organization based out in Silver Spring, Maryland, United States. It is known for research contribution in the topics: Algal bloom & Population. The organization has 500 authors who have published 643 publications receiving 46096 citations.

Intercomparison Between Towed And Stationary Acoustic Doppler Current Profilers

Abstract: This paper discusses the use of a towed acoustic Doppler current profiler (ADCP) for the purpose of evaluating in situ current meters. Data are presented from comparison tests between a towed and bottom-mounted ADCP. Velocity contours parallel and transverse to the main navigation channel under the Sunshine Skyway Bridge (SSB) in Tampa, Florida from a 600 KHz towed ADCP are compared to bottom-mounted current profiles from a 1200 KHz ADCP placed under the SSB. Data are presented to show instrument differences which are a combiination of random and systematic error. The study finds that the bottom-mounted ADCP is measuring current speeds accurately and is in the optimal location to report maximum channel currents under the SSB. The present location of the bottom-mounted ADCP under the SSB in the middle of the main navigation channel reports velocities accurate to 5 cmls. This metho+ is considered a viable technique for evaluating the reliability of moored or bottom-mounted units.

A brief survey of oil spill weathering models

Abstract: This chapter reviews traditional methods to characterize spilled oil and to model significant physical and chemical weathering processes that such oil will likely undergo. These processes include spreading, dispersion, oil–particle aggregation, emulsification, evaporation, dissolution, and photooxidation. However, important biologically influenced processes such as biodegradation and marine snow are not covered in this chapter as they are outside the expertise of the author. Excluded from this review for brevity are spills under special conditions such as spills in rivers, marshes, and, except for a minor aside, ice-infested waters. Useful precursor environmental models such as wave development and Langmuir processes are briefly summarized as these have a large impact on oil slick behavior. In recognition of the increased research effort springing from recent spills of international significance, the author includes a representative but not comprehensive discussion of resulting important new findings that may alter traditional ideas on spill weathering and behavior.

On the measurement of currents for real-time applications: An overview

Abstract: The greatest benefit of some of the new current measurement techniques being developed may not be in the areas of improved accuracy or handling the dynamics better; it may simply be in their ability to avoid many of the problems that cause so much inconvenience and expense when using conventional methods. Some of these new techniques are either land-based or installed in the water at the edge of a waterway, and thus are no more difficult to maintain than a tide gage. Such techniques are, therefore, appropriate for permanent real-time systems in harbors and estuaries. In this paper various current measurement techniques are looked at from the point of view of their usefulness in real-time harbor applications. Various techniques for real-time applications over the continental shelf are also discussed.

Algorithms for Processing and Analysis of Ocean Color Satellite Data for Coastal Case 2 Waters

Abstract: SeaWiFS has the ability to enhance our understanding of many oceanographic processes. However, its utility in the coastal zone has been limited by valid bio-optical algorithms and by the determination of accurate water reflectances, particularly in the blue bands (412-490 nm), which have a significant impact on the effectiveness of all bio-optical algorithms. We have made advances in three areas: algorithm development (Table 16.1), field data collection, and data applications.

A model of the effects of a shelf break and of wind stress on the dynamics of oceanic fonts

Abstract: A mathematical model dependent upon across-shelf and vertical coordinates, but independent of along-shelf coordinates is used to study the effects of a shelf break and of wind stress on the dynamics of oceanic fronts. The governing equations are the coupled diffusion equations and the full non-linear Navier-Stokes equations for a fluid on a f-plane. The problem is given variable bottom topography and/or an applied wind stress. A weak front is developed initially with no wind stress. When equlibrium is reached the wind stress is applied, which causes mixing and a forcing of the front off the shelf break.