Proceedings OCEANS最新文献

{"title":"Geosat Altimeter Observations of the Distribution and Movement of Sea Surface Height Anomalies in the North-East Pacific","authors":"J. Gower","doi":"10.1109/OCEANS.1989.586717","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.586717","url":null,"abstract":"","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123872041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acoustic Data Acquisition And Processing Systems","authors":"Grace R. Kamitakahara, R. Teichrob","doi":"10.1109/OCEANS.1989.587512","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.587512","url":null,"abstract":"Acoustic oceanography places special demands on high speed, high volume data collection and processing. Digital audio equipment provides opportunity for high quality digital recording of acoustic signals. Systems typically include one or more acoustic transducers from which signals are recorded through an audio PCM (pulse code modulation) unit onto a VCR (video cassette recorder), recording two 16-bit channels at 44.1 kHz each for up to 8 hours (Fig. la). System variations involve modifications to the PCM to allow input of additional digital data on the VCR recording and to extract the decoded serial data on playback in order to convert it to parallel for input to a computer. Different configurations may multiplex the analogue inputs (Fig. lb), or enter digital data directly into the encoder (Fig. IC). Playback systems allow the PCM to decode and error-correct the data for processing by computers (Fig 2a). The data is recovered from VCR in stream mode at the same data rate at which it was recorded (i.e. 176 K bytes per second). Real-time techniques to handle the data volume and rapid processing allow data to be stored onto 9 track tape (Fig. 3a); overviewed using histograms (Fig. 3b); windowed on selective events (Fig. 3c); averaged and processed in other ways using DSP (digital signal processing) hardware (Fig. 2b). These algorithms greatly compress the data, reducing it by 10 to 1000 times depending on the application. a n a l o g i n p u t s P C M V C R (a1","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123644362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocean Dumping Risk Assessment: Analysis Of Uncertainties Imposed By Variability In Chemical Bioconcentration, Commercial Fish Landings, And Human Fish Consumption","authors":"J. Lipton","doi":"10.1109/OCEANS.1989.586859","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.586859","url":null,"abstract":"Human consumption of marine organisms that have been contaminated by municipal sewage sludges dumped of the U.S. mid-Atlantic coast may pose significant health risks. In order to protect human health, researchers have modeled these risks. Such models have failed to reflect uncertainties imposed by parameter variability. An analysis was conducted to examine the effects of variability in bioconcentration, commercial fish landings, and seafood consumption on risk estimates. Calculated human health risks varied by three orders of magnitude when variability in these parameters was included in the risk model. Published bioconcentration factors (BCF) for DDT and for PCBs in different fish species were found to be log-normally distributed ( v = 5 . 0 , 0 = . 6 for DDT and p=5.2, a=.8 for PCBs) . This relationship was used to model health risks stemming from consumption of species for which BCF are unknown. The probability of health risks exeeding critical regulatory threshold (e.g. 10 -6) was estimated. Risk \"contingency tables,\" indicating the probability of exceeding target risk thresholds under different model assumptions, were then compiled. Finally, distributions of BCF, commercial fish landings, and fish consumption were used in a Monte-Carlo simulation of human health risks. Results indicate that parameter variability can lead to a range of estimated health risks which straddles current risk-management thresholds. Thus, if not explicitly considered, this variability can lead to errors in risk-based decision-making.","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123821950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Refractive Index Measurement Of Seawater: Several Methods","authors":"F. Caimi","doi":"10.1109/OCEANS.1989.587125","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.587125","url":null,"abstract":"","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128183090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Evaluation Of The Performance Of Five Types Of Sediment Toxicity Tests","authors":"E. Long, M. Buchman","doi":"10.1109/OCEANS.1989.586829","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.586829","url":null,"abstract":"The relative sensitivity, analytical precision, discriminatory power, concordance among end-points and concordance with sediment chemistry were compared among five sediment toxicity tests. The tests were performed with aliquots of 15 composited, homogenized sediment samples collected in San Francisco Bay and Tomales Bay, California. The end-points evaluated were: survival and avoidance of solid phase sediments by the amph ipods R h e p o x y n i u s abroriius and Anipelisca abdita; survival and abnormal development i n the embryos of the mussel Mytilus edulis exposed to elutriates; fertilization success, abnormal development, echinochrome pigment content, incidence of micronuclei, and other cytological/cytogenetic abnormalities and mitoses per embryo in the embryos of the urchin StrorigyloceNtrotus purpuratus exposed to elutriates; and survival and egg production in the polychaete Dinophilus gyrocil iatus exposed to interstitial (pore) water. Each sample was also tested for trace metal and organic compound concentration, organic carbon content, and texture. Two of the five tests (survival among M. edulis and survival among R . abroriius) were highly sensitive to the samples and had relatively high precision, but the results were correlated most highly with sedimentological variables. One of the tests (survival ainonz A. abdita) was relatively insensitive, but the METHODS Fifteen sediment samples collected in clusters of three from each of five locations in the San Francisco Bay/Tomales Bay, California area were tested. Sampling locations were selected to represent a gradient from relatively highly contaminated to minimally contaminated conditions. Each toxicity test was also performed with sediment from either the respective animal collection site or from a presumed pristine site near the laboratory in which the tests were performed. These sediments were treated as laboratory controls. Since the same material was not used as controls for all the toxicity tests, the results of testing the controls were not strictly equivalent among the toxicity tests. Nevertheless, the controls served as independent test media for evaluating the viability of the test organisms and the internal consistency of testing procedures. Also, the results from testing the controls were used to determine which samples were indicated to be \"toxic,\" i.e., significantly different from respective controls, in the data analyses. Sediment Sampling. Sediments were sampled in February 1987 with a 0.1m2 Ybung grab sampler (similar to a Van Veen grab sampler). Multiple (usually 6 to 10) grab samples,were taken at each station and the upper 1 cm of sediment was removed with a Teflonlined calibrated scoop and placed in a Teflon-l'ined, stainless steel basin until about 7L of sediment had been accumulated and composited to form each sample. The sediments were then stirred until the composited sample appeared homogeneous. Portions of varying sizes of the composited samples then were remov","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128887547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimum Hull Form Of The Ocean Stable Laboratory (Tension Leg Platform Type)","authors":"T. Yasuda, K. Kudo","doi":"10.1109/OCEANS.1989.587078","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.587078","url":null,"abstract":"","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128344522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimum Scatterometer Frequency for Sensing SEA Surface Wind Speed in Cloudy Conditions","authors":"A. Sarkar, R. Kumar, M. Mohan","doi":"10.1109/OCEANS.1989.586718","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.586718","url":null,"abstract":"","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"2001 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128563550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absolute Gravity Measurements: Global Sea Level Change","authors":"V.E. Carter, G. Peter","doi":"10.1109/OCEANS.1989.592867","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.592867","url":null,"abstract":"Melting of the ice masses that covered large portions of North America and northern Europe during the last ice age have redistributed major loads on the crust and mantle. The process has caused an upward rebound that still exceeds 1 cm/year in Canada and Scandinavia and a few millimeters/year in more southerly areas. The formation of foldbelts and basins by global tectonic forces is another source for uplifts and subsidences of similar magnitude in many regions of the world. In the United States several areas are affected by vertical land motions, including the general area of the Great Lakes, large sections of the Gulf of Mexico, and the Atlantic and Pacific coasts. In order to detect eustatic sea level changes from tidal records, the vertical motions affecting coastal areas have to be determined accurately. A quick and relatively inexpensive way of monitoring vertical motions is through repeat gravity observations. Discounting changes of density redistribution, elevation changes on the surface of the Earth are reflected in changes in the value of gravity. For a 1 cm elevation change the gravity change is approximately 3 pGals. A change of this size in gravity now can be detected, using an absolute gravity instrument developed by the Joint Institute for Laboratory Astrophysics (JILA). During the past 2 years the National Geodetic Survey (NGS) has been using this instrument to test its performance, and to develop and refine observational, data reduction, and analysis procedures. Absolute gravity has been determined at more than 40 sites, and several more sites have been evaluated for suitability for future long-term observations. From repeat measurements at 10 of the observation points we estimate that at carefully selected sites the measurements have a precision of better than 1 to 2 pGals and an accuracy of perhaps 3 to 5 pGals. Based on these encouraging results, the NGS has begun the development of an absolute gravity reference network to monitor vertical motions in North America. The gravity reference network will be used to derive improved estimates of vertical motions caused by glacial rebound and tectonic forces at tide gauge stations. This will improve the estimates of the change in global sea level from historical tide gauge records, as well as current and future observations. We believe that the use of this new absolute gravity instrument may be the most cost effective and sensitive tool for monitoring and mapping vertical motions during the next decade.","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129849365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sea Ice Drift And Deformation In The Western Arctic","authors":"C. Pease, P. Turet","doi":"10.1109/OCEANS.1989.587524","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.587524","url":null,"abstract":"Groups of ARGOS sea ice buoys were deployed in the Bering, Chukchi, and Beaufort seas over a decade. The pattern that emerges shows that Norton Sound and the coastal zone of the Seward Peninsula episodically produce ice that is both exported to the Arctic through Bering Strait and fed to the conveyor belt system of the southem Bering Sea. Additional major ice formation centers for the Bering system are the west coast of Alaska from the Yukon to Nunivak Island during easterly winds and the St. Lawrence Island polynya and Chukotsk Peninsula during northerly winds. Additional ice formation centers for the Chukchi system are the west coast of Alaska during easterly winds and intrusions of ice from the Beaufort coastal zone. There is a net partitioning of the drift in the Chukchi between the Alaskan Coastal Current and the broad flow out Hope Valley toward Wrangel Island. Although the vector mean drift in Bering Strait is northward, the mean is smaller than the currents at depth because of wind reversals and the interannual variability is large. Mesoscale strain was estimated for triplets of ARGOS buoy tracks in the westem Arctic. On the open Bering Shelf tidal energy dominates both the velocity field (20 50 %) and the components of the strain field. Also the M4 tidal component of the ice velocity is about 45% of the amplitude of M,, while M, in the ocean current is about 2%. This partial shift from semi-diurnal (12.4-hr) to 6.2-hour energy is caused by a compressional wave which propagates through the pack at both extremes of the semi-diumal tidal oscillation. Daily gaps in the ARGOS coverage due to the distribution of satellite passes at low polar latitudes can be bridged best by using the tidal information from regional current measurements with appropriately enhanced M, to help generate a synthetic series, rather than least-squares or spline curve fitting techniques.","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128294729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Supervisory Control Architecture for Sea Grant I Rov","authors":"D. Humphrey","doi":"10.1109/OCEANS.1989.586694","DOIUrl":"https://doi.org/10.1109/OCEANS.1989.586694","url":null,"abstract":"This paper describes a supervisory control system for remotely operated vehicles (ROV) and details its implementation on the Sea Grant I ROV. The Sea Grant I was donated to MIT in 1 9 8 2 in non-operating condition and by 1 9 8 6 was operable but only under manual control. The hardware and software of the current supervisory control system is built upon that which existed in 1986 . Those features of the old software which were good have been retained but the majority of the system software is either completely new or has been revised. The specific features of the new system are described in detail along with the system analysis which determined the method of software implementation. The new system is flexible in allowing the operator to choose the combination of control modes best suited to a particular task. Results of actual tests are provided which show that good control of the vehicle has been obtained in a fashion which is largely independent of operator experience. An example of water temperature monitoring is demonstrated. The supervisory control system which has been implemented on the Sea Grant I makes the ROV an excellent system for carrying out research in ROV control systems or in the applications of ROVs to underwater scientific research.","PeriodicalId":331017,"journal":{"name":"Proceedings OCEANS","volume":"25 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128737891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}