Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625521
G. Garnaga, Z. Stukova
The development of complex investigations is a useful tool for determining of the marine environment contamination with oil products. In the frame of national monitoring program, the concentrations of total oil hydrocarbons (THCs) and polycyclic aromatic hydrocarbons (PAHs) in water and bottom sediments were analyzed and numbers of oil-oxidizing bacteria were determined. Investigations show that THC concentrations in water frequently exceed the maximum permissible level (0.05 mg/L). Long-term studies show that there is an increasing tendency of THC concentrations in some regions of the Lithuanian part of the Baltic Sea. Concentrations of PAHs in water of the Baltic Sea and the Curonian Lagoon do not exceed maximum permissible levels. PAH concentrations in sediments are close to background values. Investigation result also reveal that the contamination of sediments with PAHs is apparently coming from the use of diesel engines. The comparison of quantitative annual distribution of oil-oxidizing bacteria in different regions shows that they occur in greater abundance in the intermediate waters, i.e. in the Baltic Sea area which is under the impact of the Curonian Lagoon waters and in the Klaipeda Strait. According to the investigation results of THCs, PAHs and oil-oxidizing bacteria, the Klaipeda Strait is the mostly contaminated with oil products. Complex investigations and monitoring of marine environment allow permanent control of the contamination and quality of the Baltic Sea and the Curonian Lagoon environment.
{"title":"Contamination of the south-eastern Baltic Sea and the curonian lagoon with oil products","authors":"G. Garnaga, Z. Stukova","doi":"10.1109/BALTIC.2008.4625521","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625521","url":null,"abstract":"The development of complex investigations is a useful tool for determining of the marine environment contamination with oil products. In the frame of national monitoring program, the concentrations of total oil hydrocarbons (THCs) and polycyclic aromatic hydrocarbons (PAHs) in water and bottom sediments were analyzed and numbers of oil-oxidizing bacteria were determined. Investigations show that THC concentrations in water frequently exceed the maximum permissible level (0.05 mg/L). Long-term studies show that there is an increasing tendency of THC concentrations in some regions of the Lithuanian part of the Baltic Sea. Concentrations of PAHs in water of the Baltic Sea and the Curonian Lagoon do not exceed maximum permissible levels. PAH concentrations in sediments are close to background values. Investigation result also reveal that the contamination of sediments with PAHs is apparently coming from the use of diesel engines. The comparison of quantitative annual distribution of oil-oxidizing bacteria in different regions shows that they occur in greater abundance in the intermediate waters, i.e. in the Baltic Sea area which is under the impact of the Curonian Lagoon waters and in the Klaipeda Strait. According to the investigation results of THCs, PAHs and oil-oxidizing bacteria, the Klaipeda Strait is the mostly contaminated with oil products. Complex investigations and monitoring of marine environment allow permanent control of the contamination and quality of the Baltic Sea and the Curonian Lagoon environment.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79155555","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625506
A. Kostianoy, P. Ermakov, D. Soloviev
Shipping The Nord Stream is a more than 1200-km long gas pipeline that will link Russia to Europe via the Baltic Sea from Vyborg in Russia to Greifswald in Germany. The construction process of the pipeline may cause, in particular, the following impact on the marine environment: (i) oil pollution due to the operation of ships, pipelay vessel, dredge ships and mechanisms in the sea; (ii) increase of suspended matter concentration due to dumping of sand and gravel, and dredging operations; (iii) provoking of local algal bloom events in summertime due to vertical mixing resulted from dumping and dredging works. Thus, there are two very important and interrelated tasks: (i) to monitor in the operational regime the ecological state of the sea at the site of the pipeline construction, and (ii) to discriminate between natural effects and anthropogenic impacts, related to the construction itself.
{"title":"Complex satellite monitoring of the nord stream gas pipeline construction","authors":"A. Kostianoy, P. Ermakov, D. Soloviev","doi":"10.1109/BALTIC.2008.4625506","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625506","url":null,"abstract":"Shipping The Nord Stream is a more than 1200-km long gas pipeline that will link Russia to Europe via the Baltic Sea from Vyborg in Russia to Greifswald in Germany. The construction process of the pipeline may cause, in particular, the following impact on the marine environment: (i) oil pollution due to the operation of ships, pipelay vessel, dredge ships and mechanisms in the sea; (ii) increase of suspended matter concentration due to dumping of sand and gravel, and dredging operations; (iii) provoking of local algal bloom events in summertime due to vertical mixing resulted from dumping and dredging works. Thus, there are two very important and interrelated tasks: (i) to monitor in the operational regime the ecological state of the sea at the site of the pipeline construction, and (ii) to discriminate between natural effects and anthropogenic impacts, related to the construction itself.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81634134","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625491
R. Jasinevicius, V. Petrauskas
After widely known implementations of perfect ideas, expressed by researchers R. Axelrod, L. Zadeh and B. Kosko, the fuzzy cognitive map (FCM) became an important tool for decision makers in various practical areas, such as business evaluation, risk management, international policy making, medical diagnostics and others. The principle possibility of FCM involvement into a regional oceanic modeling system (ROMS) was presented during the US/EU Baltic International Symposium in Klaipeda in May 2006. Todaypsilas experience permits to extend the concept of FCM nodes, including additional fuzzy expert knowledge and enriching the representation of real situations under consideration. This paper presents a systematic approach, based on the authorspsila research, to the idea of FCM extension and its transformation into a rule-based fuzzy expert map (FEM), presents a simplified fragment of FEM use for a port security system, and discusses further perspectives of developing new tools for decision makers in risk management systems in general.
{"title":"Fuzzy expert maps for risk management systems","authors":"R. Jasinevicius, V. Petrauskas","doi":"10.1109/BALTIC.2008.4625491","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625491","url":null,"abstract":"After widely known implementations of perfect ideas, expressed by researchers R. Axelrod, L. Zadeh and B. Kosko, the fuzzy cognitive map (FCM) became an important tool for decision makers in various practical areas, such as business evaluation, risk management, international policy making, medical diagnostics and others. The principle possibility of FCM involvement into a regional oceanic modeling system (ROMS) was presented during the US/EU Baltic International Symposium in Klaipeda in May 2006. Todaypsilas experience permits to extend the concept of FCM nodes, including additional fuzzy expert knowledge and enriching the representation of real situations under consideration. This paper presents a systematic approach, based on the authorspsila research, to the idea of FCM extension and its transformation into a rule-based fuzzy expert map (FEM), presents a simplified fragment of FEM use for a port security system, and discusses further perspectives of developing new tools for decision makers in risk management systems in general.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89665736","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625554
M. Migliaccio, A. Gambardella, F. Nunziata
Synthetic aperture radar (SAR) ship detection is an important application in the context of environment and security monitoring. Ship detection techniques are generally based on statistically significant contrast between the ship and the local ocean background. Typically, high resolution (few tenths of meters) SAR images need to be considered. Such images are heavily affected by the presence of the speckle, and, for this reason, many ship detection algorithms employ constant false alarm rate (CFAR) algorithms. In this study, a different approach is proposed. The speckle is not mitigated but considered as a source of information. The ship is considered as a dominant scatterer responsible for a strong and coherent backscatter signal. Hence, the different behavior of the speckle statistics in presence of a dominant scatterer exploited. A new simple and very effective filtering technique, which is able to process high resolution SAR images, has been conceived an implemented. Experiments, accomplished over C-band Single Look Complex ERS 1/2 SAR images, show the effectiveness of this new approach for ship detection.
{"title":"Ship detection over single-look complex SAR images","authors":"M. Migliaccio, A. Gambardella, F. Nunziata","doi":"10.1109/BALTIC.2008.4625554","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625554","url":null,"abstract":"Synthetic aperture radar (SAR) ship detection is an important application in the context of environment and security monitoring. Ship detection techniques are generally based on statistically significant contrast between the ship and the local ocean background. Typically, high resolution (few tenths of meters) SAR images need to be considered. Such images are heavily affected by the presence of the speckle, and, for this reason, many ship detection algorithms employ constant false alarm rate (CFAR) algorithms. In this study, a different approach is proposed. The speckle is not mitigated but considered as a source of information. The ship is considered as a dominant scatterer responsible for a strong and coherent backscatter signal. Hence, the different behavior of the speckle statistics in presence of a dominant scatterer exploited. A new simple and very effective filtering technique, which is able to process high resolution SAR images, has been conceived an implemented. Experiments, accomplished over C-band Single Look Complex ERS 1/2 SAR images, show the effectiveness of this new approach for ship detection.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84518104","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625495
V. Zhurbas, J. Elken, G. Vali
A model system consisting of a circulation model and a random-walk model is developed to simulate suspended particulate matter transport in the bottom boundary layer (BBL) of the southern Baltic Sea. The circulation model is based on POM, the Princeton Ocean Model, in which the vertical grid size is refined towards the bottom in order to resolve BBL properly. 3D fields of velocity, vertical and lateral apparent diffusivities generated by the circulation model are used as an input for the random walk model to simulate transport and dispersion of particles with prescribed settling velocity. The random-walk scheme allows for non-uniform vertical profiles of the vertical apparent diffusivity, and test runs have been done to make sure that the model does not display unrealistic removal of particles from highly turbulent BBL and further accumulation in low-diffusivity above-lying layers. A number of numerical experiments have been performed to study pathways of suspended particles released in the BBL in the centre of the Bornholm Deep at different wind conditions. At northerly and easterly winds the particles initially move westward and then get involved into either northern or southern detours around the Deep. The particles from the northern detour are finally absorbed into the Slupsk Furrow while those of the southern detour do not enter the Furrow keeping on cyclonic rotation within the Bornholm Basin. To the contrast, for the westerly and southerly wind conditions the particles move to the northeast for some 20 km and then get involved into the cyclonic rotation. The cyclonic rotation implies the convergence of currents in the BBL due the Ekman transport and, in view of continuity, the upwelling, so that the particles will remain trapped within the Bornholm Deep if the settling velocity is large enough to overcome the upwelling. Since the westerly wind conditions dominate in the climatic sense, the trapping effect may be considered as an important factor that controls dispersion of chemical warfare agents dumped in the Bornholm Deep after the World War II.
{"title":"Pathways of suspended particles released in the bottom boundary layer of the Bornholm Deep, Baltic Sea (numerical simulations)","authors":"V. Zhurbas, J. Elken, G. Vali","doi":"10.1109/BALTIC.2008.4625495","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625495","url":null,"abstract":"A model system consisting of a circulation model and a random-walk model is developed to simulate suspended particulate matter transport in the bottom boundary layer (BBL) of the southern Baltic Sea. The circulation model is based on POM, the Princeton Ocean Model, in which the vertical grid size is refined towards the bottom in order to resolve BBL properly. 3D fields of velocity, vertical and lateral apparent diffusivities generated by the circulation model are used as an input for the random walk model to simulate transport and dispersion of particles with prescribed settling velocity. The random-walk scheme allows for non-uniform vertical profiles of the vertical apparent diffusivity, and test runs have been done to make sure that the model does not display unrealistic removal of particles from highly turbulent BBL and further accumulation in low-diffusivity above-lying layers. A number of numerical experiments have been performed to study pathways of suspended particles released in the BBL in the centre of the Bornholm Deep at different wind conditions. At northerly and easterly winds the particles initially move westward and then get involved into either northern or southern detours around the Deep. The particles from the northern detour are finally absorbed into the Slupsk Furrow while those of the southern detour do not enter the Furrow keeping on cyclonic rotation within the Bornholm Basin. To the contrast, for the westerly and southerly wind conditions the particles move to the northeast for some 20 km and then get involved into the cyclonic rotation. The cyclonic rotation implies the convergence of currents in the BBL due the Ekman transport and, in view of continuity, the upwelling, so that the particles will remain trapped within the Bornholm Deep if the settling velocity is large enough to overcome the upwelling. Since the westerly wind conditions dominate in the climatic sense, the trapping effect may be considered as an important factor that controls dispersion of chemical warfare agents dumped in the Bornholm Deep after the World War II.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88483624","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625535
U. Lips, I. Lips, T. Liblik, J. Elken
Weekly mapping of vertical temperature and salinity fields was carried out across the Gulf of Finland in summer 2006 and spring 2007. Using successive cross-gulf vertical sections of salinity and wind data from the region the variations of estuarine and transverse circulation are described. Changes of deep layer phosphate-phosphorus concentrations are found to be related to the described variations in circulation patterns in a season with strong vertical stratification of the water column. Cumulative volume transport estimates were obtained using the results of a 3D baroclinic circulation model (HIROMB). We suggest that the north-easterly winds, which intensify the estuarine circulation and lead to the upwelling events along the southern coast of the Gulf of Finland, could have a major impact to the Gulfpsilas ecosystem by importing more saline and phosphorus rich waters. These events with many-fold more intense upward movement and mixing of deep waters (upward diapycnal transport) could contribute significantly to the ventilation of deep layers of the northern Baltic proper.
{"title":"Estuarine transport versus vertical movement and mixing of water masses in the Gulf of Finland (Baltic Sea)","authors":"U. Lips, I. Lips, T. Liblik, J. Elken","doi":"10.1109/BALTIC.2008.4625535","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625535","url":null,"abstract":"Weekly mapping of vertical temperature and salinity fields was carried out across the Gulf of Finland in summer 2006 and spring 2007. Using successive cross-gulf vertical sections of salinity and wind data from the region the variations of estuarine and transverse circulation are described. Changes of deep layer phosphate-phosphorus concentrations are found to be related to the described variations in circulation patterns in a season with strong vertical stratification of the water column. Cumulative volume transport estimates were obtained using the results of a 3D baroclinic circulation model (HIROMB). We suggest that the north-easterly winds, which intensify the estuarine circulation and lead to the upwelling events along the southern coast of the Gulf of Finland, could have a major impact to the Gulfpsilas ecosystem by importing more saline and phosphorus rich waters. These events with many-fold more intense upward movement and mixing of deep waters (upward diapycnal transport) could contribute significantly to the ventilation of deep layers of the northern Baltic proper.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89125908","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625507
T. Fristedt, B. Lundqvist, M. Aklint, J. Hall, P. Soderberg
In the ocean there are mainly two ways of characterizing the properties of the sediment structure. One technique is to observe the properties by physically collecting core samples by in-situ instrumentation. The other is to use remote techniques to estimate the acoustic properties of the sediment and from these observations invert the sediment thickness and sound velocity by interpreting the reflected sound. One of the drawbacks of the acoustic technique is that its range sometimes may be limited by gas trapped in the sediments, which severely impedes the sound propagation. This situation is often encountered in the Stockholm archipelago. For these areas it is possible to use low-frequency electromagnetic fields to achieve basically the same type of sediment property description. A model-based technique has been developed for characterizing the sediment conductivity and thickness by inversion of electromagnetic data. A field trial was undertaken in May 2007 where electromagnetic data was collected by a towed sensor which also included a one-axis electromagnetic multi-frequency source in addition to the electric receiver. Results from the analysis are presented and discussed in terms of its appropriateness for use in footprint techniques for determining sediment layer thickness and sediment conductivity along the tow track.
{"title":"Electromagnetic footprint measurements from a towed platform for characterizing sub-bottom conductivities and structures in the Stockholm archipelago","authors":"T. Fristedt, B. Lundqvist, M. Aklint, J. Hall, P. Soderberg","doi":"10.1109/BALTIC.2008.4625507","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625507","url":null,"abstract":"In the ocean there are mainly two ways of characterizing the properties of the sediment structure. One technique is to observe the properties by physically collecting core samples by in-situ instrumentation. The other is to use remote techniques to estimate the acoustic properties of the sediment and from these observations invert the sediment thickness and sound velocity by interpreting the reflected sound. One of the drawbacks of the acoustic technique is that its range sometimes may be limited by gas trapped in the sediments, which severely impedes the sound propagation. This situation is often encountered in the Stockholm archipelago. For these areas it is possible to use low-frequency electromagnetic fields to achieve basically the same type of sediment property description. A model-based technique has been developed for characterizing the sediment conductivity and thickness by inversion of electromagnetic data. A field trial was undertaken in May 2007 where electromagnetic data was collected by a towed sensor which also included a one-axis electromagnetic multi-frequency source in addition to the electric receiver. Results from the analysis are presented and discussed in terms of its appropriateness for use in footprint techniques for determining sediment layer thickness and sediment conductivity along the tow track.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82658314","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625515
E. Ramsey, A. Rangoonwala
We describe newly developed remote sensing tools to map the localized occurrences and regional distribution of the marsh dieback in coastal Louisiana. As a final goal of our research and development, we identified what spectral features accompanied the onset of dieback and could be directly linked to the optical signal measured at the satellite. In order to accomplish our research goal, we carried out two interlinked objectives. First, we determined the spectral features within the hyperspectral spectra of the impacted plant that could be linked to the spectral return. This was accomplished by measuring the differences in leaf optical properties of impacted and non impacted marsh plants in such a way that the measured differences could be linked to the dieback onset and progression. The spectral analyses were constrained to selected wavelengths (bands of reflectance data) historically associated with changes in leaf composition and structure caused by changes in the plant biophysical environment. Second, we determined what changes in the canopy reflectance (canopy signal sensed at the satellite) could be linked to dieback onset and progression. Third, we transformed a suite of six Landsat Thematic Mapper images collected before, during, and in the final stages of dieback to maps of dieback occurrences.
{"title":"Characterizing the marsh dieback spectral response at the plant and canopy level with hyperspectral and temporal remote sensing data","authors":"E. Ramsey, A. Rangoonwala","doi":"10.1109/BALTIC.2008.4625515","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625515","url":null,"abstract":"We describe newly developed remote sensing tools to map the localized occurrences and regional distribution of the marsh dieback in coastal Louisiana. As a final goal of our research and development, we identified what spectral features accompanied the onset of dieback and could be directly linked to the optical signal measured at the satellite. In order to accomplish our research goal, we carried out two interlinked objectives. First, we determined the spectral features within the hyperspectral spectra of the impacted plant that could be linked to the spectral return. This was accomplished by measuring the differences in leaf optical properties of impacted and non impacted marsh plants in such a way that the measured differences could be linked to the dieback onset and progression. The spectral analyses were constrained to selected wavelengths (bands of reflectance data) historically associated with changes in leaf composition and structure caused by changes in the plant biophysical environment. Second, we determined what changes in the canopy reflectance (canopy signal sensed at the satellite) could be linked to dieback onset and progression. Third, we transformed a suite of six Landsat Thematic Mapper images collected before, during, and in the final stages of dieback to maps of dieback occurrences.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75903629","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625523
S. Ermakov
A brief review of experiments on damping of short wind waves due to surfactant (monomolecular) and oil films carried out at the Institute of Applied Physics RAS using radar and optical methods is given. The damping degree of wind waves (spectral contrast) in film slicks is analyzed in a wide (decimeter-centimetre-scale) wavelength range of wind waves at different wind speeds and physical characteristics of films. A simple local balance model of the wind wave spectrum is developed to describe the film effect on short wind waves. Differencies in the spectral contrasts for film slicks and for some ldquolook-alikesrdquo, in particular, for wind depression areas (WDA) are revealed: the spectral contrast for film slicks increases with surface wave number, while for WDA the contrast is practically constant for decimeter-centimeter-scale wind waves. The specific behaviour of the spectral contrast can be used as a slick ldquospectral signrdquo.
{"title":"Possibilities of identification of oil films using radar probing of the sea surface","authors":"S. Ermakov","doi":"10.1109/BALTIC.2008.4625523","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625523","url":null,"abstract":"A brief review of experiments on damping of short wind waves due to surfactant (monomolecular) and oil films carried out at the Institute of Applied Physics RAS using radar and optical methods is given. The damping degree of wind waves (spectral contrast) in film slicks is analyzed in a wide (decimeter-centimetre-scale) wavelength range of wind waves at different wind speeds and physical characteristics of films. A simple local balance model of the wind wave spectrum is developed to describe the film effect on short wind waves. Differencies in the spectral contrasts for film slicks and for some ldquolook-alikesrdquo, in particular, for wind depression areas (WDA) are revealed: the spectral contrast for film slicks increases with surface wave number, while for WDA the contrast is practically constant for decimeter-centimeter-scale wind waves. The specific behaviour of the spectral contrast can be used as a slick ldquospectral signrdquo.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79680373","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}
Pub Date : 2008-05-27DOI: 10.1109/BALTIC.2008.4625534
J. Kotta, K. Herkül, I. Kotta, H. Orav-Kotta, R. Aps
The effect of dredging on the biomass structure of benthic invertebrate communities was examined at 9 sites in the northeastern Baltic Sea during 2002-2007. We analyzed whether and how bottom topography, depth and sediment type contributed to these relationships. In general, the effects of dredging on benthic invertebrates were weak. Dredging clearly increased the biomass of bivalves but the communities recovered in about a year. Bottom topography affected the response of invertebrates to dredging. Flat bottoms were more sensitive to dredging compared to sites situating on slopes. Spatial modelling was proved as a useful tool to predict spatial variability in the effects of dredging on benthic invertebrate communities.
{"title":"Effects of harbour dredging on soft bottom invertebrate communities: Does environmental variability affect the community responses?","authors":"J. Kotta, K. Herkül, I. Kotta, H. Orav-Kotta, R. Aps","doi":"10.1109/BALTIC.2008.4625534","DOIUrl":"https://doi.org/10.1109/BALTIC.2008.4625534","url":null,"abstract":"The effect of dredging on the biomass structure of benthic invertebrate communities was examined at 9 sites in the northeastern Baltic Sea during 2002-2007. We analyzed whether and how bottom topography, depth and sediment type contributed to these relationships. In general, the effects of dredging on benthic invertebrates were weak. Dredging clearly increased the biomass of bivalves but the communities recovered in about a year. Bottom topography affected the response of invertebrates to dredging. Flat bottoms were more sensitive to dredging compared to sites situating on slopes. Spatial modelling was proved as a useful tool to predict spatial variability in the effects of dredging on benthic invertebrate communities.","PeriodicalId":6307,"journal":{"name":"2008 IEEE/OES US/EU-Baltic International Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83451542","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}
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