The Experts below are selected from a list of 63 Experts worldwide ranked by ideXlab platform
Olga Lavrova - One of the best experts on this subject based on the ideXlab platform.
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IGARSS - Oil Slicks from Natural Hydrocarbon Seeps in the Southeastern Black Sea, Their Drift and Fate as Observed via Remote Sensing
IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018Co-Authors: M. Mityagina, Olga LavrovaAbstract:The paper discusses our studies of oil pollution due to natural hydrocarbon seeps on the seafloor in the South-Eastern Black Sea. The patterns of surface oil pollution of the South-Eastern Black Sea are analyzed and described. Trajectories of oil slicks from seabed seepages are analyzed on the base of satellite remote sensing data for 2010–2017. The quantitative assessment of inter-annual, seasonal and spatial variability of natural oil pollution of the region of interest is performed. Maps of oil pollution risks of sea surface and shores in the South-Eastern Black Sea are created. The precise estimation of the actual seafloor source location is made on the base of satellite data. The impact of dynamic and circulation processes and natural factors (Current Meandering, vortical activity, and wind patterns) on the stretching, spread, and disappearance of oil films is discussed.
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Multi-sensor satellite survey of natural oil slicks in the southeastern Black Sea
Remote Sensing of the Ocean Sea Ice Coastal Waters and Large Water Regions 2017, 2017Co-Authors: M. Mityagina, Olga LavrovaAbstract:Results of satellite observations of the Southeastern Black Sea are presented. Our work is aimed to the development and enhancement of satellite remote sensing technics for monitoring of sea surface oil pollution caused by the natural seepages of hydrocarbons from the seabed. We showed that multi-sensor approach to the satellite remote sensing survey contributes to a more comprehensive interpretation of the data and helps in developing a better understanding of the sea surface film pollution pattern. By using high-resolution satellite data, we were able to get a clear picture of a spatial and temporal variability of surface oil films and to show that their geographical distribution correlates with geographical locations of natural hydrocarbon seeps in this region. We used SAR for the precise estimation of the actual seafloor source location. We investigated the effect of surface winds and Currents on transport, spreading, evolution, and persistence of oil slicks on the sea surface. We further demonstrated the importance of the effects of dynamic and circulation processes and natural factors (Current Meandering, vortical activity, and wind patterns) on the trajectory and fate of the released oil. We put together detailed maps of the sea surface oil pollution caused by natural hydrocarbons showings from the sea bottom in the south-eastern of the Black Sea and outlined the regions of the heaviest pollution.
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Multi-sensor satellite survey of surface oil pollution in the Caspian Sea
Remote Sensing of the Ocean Sea Ice Coastal Waters and Large Water Regions 2015, 2015Co-Authors: M. Mityagina, Olga LavrovaAbstract:The results of long-term satellite survey of the aquatic area of the Caspian Sea are presented. The patterns of surface oil pollution of the Caspian Sea are described and analysed. It is demonstrated that surface oil pollution is often caused by natural causes, namely by natural hydrocarbon seepages and mud volcanoes activity on the sea bottom. A combined analysis of oil film signatures in satellite radar and optical imagery data is performed. Mapping of the main types of surface pollution of the Caspian Sea is performed and areas of the heaviest pollution are outlined and analysed. Dependence of radar signatures of sea surface oil patches on the wind/wave conditions is investigated. The large amount of the data available allowed us to make some generalizations and obtain statistically significant results on a spatial and temporal variability of various sea surface film manifestations in SAR images. The impact of dynamic and circulation processes and natural factors (Current Meandering, vortical activity, temperature and wind patterns) on spatial and temporal distributions and intensity of oil films is studied. The connection between manifestations of natural seepages and mud volcanoes and earthquake activity in South Caspian and adjacent areas is established.
M. Mityagina - One of the best experts on this subject based on the ideXlab platform.
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IGARSS - Oil Slicks from Natural Hydrocarbon Seeps in the Southeastern Black Sea, Their Drift and Fate as Observed via Remote Sensing
IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018Co-Authors: M. Mityagina, Olga LavrovaAbstract:The paper discusses our studies of oil pollution due to natural hydrocarbon seeps on the seafloor in the South-Eastern Black Sea. The patterns of surface oil pollution of the South-Eastern Black Sea are analyzed and described. Trajectories of oil slicks from seabed seepages are analyzed on the base of satellite remote sensing data for 2010–2017. The quantitative assessment of inter-annual, seasonal and spatial variability of natural oil pollution of the region of interest is performed. Maps of oil pollution risks of sea surface and shores in the South-Eastern Black Sea are created. The precise estimation of the actual seafloor source location is made on the base of satellite data. The impact of dynamic and circulation processes and natural factors (Current Meandering, vortical activity, and wind patterns) on the stretching, spread, and disappearance of oil films is discussed.
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Multi-sensor satellite survey of natural oil slicks in the southeastern Black Sea
Remote Sensing of the Ocean Sea Ice Coastal Waters and Large Water Regions 2017, 2017Co-Authors: M. Mityagina, Olga LavrovaAbstract:Results of satellite observations of the Southeastern Black Sea are presented. Our work is aimed to the development and enhancement of satellite remote sensing technics for monitoring of sea surface oil pollution caused by the natural seepages of hydrocarbons from the seabed. We showed that multi-sensor approach to the satellite remote sensing survey contributes to a more comprehensive interpretation of the data and helps in developing a better understanding of the sea surface film pollution pattern. By using high-resolution satellite data, we were able to get a clear picture of a spatial and temporal variability of surface oil films and to show that their geographical distribution correlates with geographical locations of natural hydrocarbon seeps in this region. We used SAR for the precise estimation of the actual seafloor source location. We investigated the effect of surface winds and Currents on transport, spreading, evolution, and persistence of oil slicks on the sea surface. We further demonstrated the importance of the effects of dynamic and circulation processes and natural factors (Current Meandering, vortical activity, and wind patterns) on the trajectory and fate of the released oil. We put together detailed maps of the sea surface oil pollution caused by natural hydrocarbons showings from the sea bottom in the south-eastern of the Black Sea and outlined the regions of the heaviest pollution.
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Multi-sensor satellite survey of surface oil pollution in the Caspian Sea
Remote Sensing of the Ocean Sea Ice Coastal Waters and Large Water Regions 2015, 2015Co-Authors: M. Mityagina, Olga LavrovaAbstract:The results of long-term satellite survey of the aquatic area of the Caspian Sea are presented. The patterns of surface oil pollution of the Caspian Sea are described and analysed. It is demonstrated that surface oil pollution is often caused by natural causes, namely by natural hydrocarbon seepages and mud volcanoes activity on the sea bottom. A combined analysis of oil film signatures in satellite radar and optical imagery data is performed. Mapping of the main types of surface pollution of the Caspian Sea is performed and areas of the heaviest pollution are outlined and analysed. Dependence of radar signatures of sea surface oil patches on the wind/wave conditions is investigated. The large amount of the data available allowed us to make some generalizations and obtain statistically significant results on a spatial and temporal variability of various sea surface film manifestations in SAR images. The impact of dynamic and circulation processes and natural factors (Current Meandering, vortical activity, temperature and wind patterns) on spatial and temporal distributions and intensity of oil films is studied. The connection between manifestations of natural seepages and mud volcanoes and earthquake activity in South Caspian and adjacent areas is established.
Heesook Kang - One of the best experts on this subject based on the ideXlab platform.
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Florida Current Meandering and evolution of cyclonic eddies along the Florida Keys Reef Tract: Are they interconnected?
Journal of Geophysical Research, 2012Co-Authors: Vassiliki H. Kourafalou, Heesook KangAbstract:[1] The Florida Current (FC) is the branch of the Gulf Stream system within the Straits of Florida, connected to the Loop Current in the Gulf of Mexico. Cyclonic, cold-core eddies travel along this oceanic Current system, entering the Straits of Florida in the vicinity of the Dry Tortugas and evolving along the Florida Keys island chain and coral reefs. The development of the high-resolution (∼900 m) hydrodynamic model Florida Straits, South Florida, and Florida Keys (FKeyS), nested within a Gulf of Mexico model (both based on the Hybrid Coordinate Ocean Model), has enabled new findings in eddy variability. Together with high-resolution (∼1 km) ocean color imagery, multiyear model archives have been employed to study the changes in the position of the FC front and the relationship with eddy evolution. It was found that eddy interactions and transformations are common, with multiple eddy cells within individual eddies or new cells emerging from existing vortices. Features in the Dry Tortugas area previously thought to be semipermanent are shown to be frequently transformed and/or replenished. A mechanism of local cyclogenesis is also proposed. Incoming eddies interact with and influence the downstream propagation of previous eddies. Systems of eddies, rather than individual vortices, can form the elongated features observed between the FC front and the Atlantic Florida Keys Shelf. Topography plays an important role in eddy dissipation or growth. A close synergy between eddy evolution and FC Meandering is revealed. The results have implications on the connectivity of remote coastal and reef ecosystems.
Marie-helene Radenac - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variability of the surface chlorophyll in the western tropical Pacific from SeaWiFS data
Deep Sea Research Part I: Oceanographic Research Papers, 2006Co-Authors: Monique Messié, Marie-helene RadenacAbstract:We used Sea-viewing Wide Field-of-view Sensor (SeaWiFS) to document the seasonal cycle of surface chlorophyll in the western tropical Pacific. Surface waters in this region can be divided into two ecosystems. The western end of the cold, salty waters of the cold tongue with high nutrient low chlorophyll (HNLC) characteristics occupies most of the eastern part Of the region, while warm, fresh, and oligotrophic waters of the warm pool stand in the western part. Nevertheless, disruption of the oligotrophy may show up at different locations. We reconstructed the seasonal cycle of chlorophyll, sea surface temperature (SST), winds, and surface Currents from satellite data and satellite-derived products by extracting the annual and semi-annual harmonics of the time series at each grid point. The calculation was done for the 1999-2004 years in order to exclude the consequences of the major 1997-1998 El Nino Southern Oscillation event. The variance explained by the seasonal cycle for this period highlights three regions with high seasonality: (1) The oligotrophy/HNLC transition zone undergoes meridional seasonal displacements. The cold tongue is at its northernmost (southernmost) position during boreal spring (fall). These displacements can be explained in terms of meridional advection of chlorophyll-rich waters and are consistent with the seasonal cycle of the north and south equatorial counterCurrents that transport phytoplankton-poor waters. (2) Ocean-color images show seasonal enrichments in the far western north equatorial counterCurrent (NECC) area, especially during boreal spring. The chlorophyll maximum coincides with the maximum NECC velocity, follows a SST minimum, and occurs during the upwelling-favorable phase of the wind stress curl. We attribute these enrichments to local upwelling associated with Current Meandering, horizontal advection from further west, and transport of nutrient-rich waters by the New Guinea coastal underCurrent. (3) Near the Solomon Archipelago, we observe enhancements of chlorophyll concentration southwest of the islands in austral winter, when both the southwestward surface Currents and the southeasterly wind stress are strongest. This may be a combination of an island-mass effect and wind-driven upwelling. Horizontal advection from the Solomon area leads to an almost conCurrent seasonal chlorophyll enrichment in the northern Coral Sea. In the Gulf of Papua, high chlorophyll concentrations at the same time can be explained by the presence of a strong cyclonic circulation. This study highlights the richness of the response of surface chlorophyll to physical processes at the seasonal time scale in a region usually acknowledged as oligotrophic.
Vassiliki H. Kourafalou - One of the best experts on this subject based on the ideXlab platform.
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Florida Current Meandering and evolution of cyclonic eddies along the Florida Keys Reef Tract: Are they interconnected?
Journal of Geophysical Research, 2012Co-Authors: Vassiliki H. Kourafalou, Heesook KangAbstract:[1] The Florida Current (FC) is the branch of the Gulf Stream system within the Straits of Florida, connected to the Loop Current in the Gulf of Mexico. Cyclonic, cold-core eddies travel along this oceanic Current system, entering the Straits of Florida in the vicinity of the Dry Tortugas and evolving along the Florida Keys island chain and coral reefs. The development of the high-resolution (∼900 m) hydrodynamic model Florida Straits, South Florida, and Florida Keys (FKeyS), nested within a Gulf of Mexico model (both based on the Hybrid Coordinate Ocean Model), has enabled new findings in eddy variability. Together with high-resolution (∼1 km) ocean color imagery, multiyear model archives have been employed to study the changes in the position of the FC front and the relationship with eddy evolution. It was found that eddy interactions and transformations are common, with multiple eddy cells within individual eddies or new cells emerging from existing vortices. Features in the Dry Tortugas area previously thought to be semipermanent are shown to be frequently transformed and/or replenished. A mechanism of local cyclogenesis is also proposed. Incoming eddies interact with and influence the downstream propagation of previous eddies. Systems of eddies, rather than individual vortices, can form the elongated features observed between the FC front and the Atlantic Florida Keys Shelf. Topography plays an important role in eddy dissipation or growth. A close synergy between eddy evolution and FC Meandering is revealed. The results have implications on the connectivity of remote coastal and reef ecosystems.
