Olga Yu. Lavrova

Operational satellite monitoring of oil spill pollution in the Southeastern Baltic Sea: 1.5 Years experience

In June 2003 LUKOIL-Kaliningradmorneft initiated a pilot project, aimed to the complex monitoring of the southeastern Baltic Sea, in connection with a beginning of oil production at continental shelf of Russia in March 2004. Operational monitoring was performed in June 2004-November 2005 on the base of daily satellite remote sensing (AVHRR NOAA, MODIS, TOPEX/Poseidon, Jason-1, ENVISAT ASAR and RADARSAT SAR imagery) of sea surface temperature (SST), sea level, chlorophyll concentration, mesoscale dynamics, wind and waves, and oil spills. As a result a complex information on oil pollution of the sea, SST, distribution of suspended matter, chlorophyll concentration, sea currents and meteorological parameters has been received. In total 274 oil spills were detected in 230 ASAR ENVISAT images (400×400 km, 75 m/pixel resolution) and 17 SAR RADARSAT images (300×300 km, 25 m/pixel resolution) received during 18 months. The interactive numerical model Seatrack Web SMHI (The Swedish Meteorological and Hydrological Institute) was used for a forecast of the drift of (1) all large oil spills detected by ASAR ENVISAT in the southeastern Baltic Sea and (2) virtual (simulated) oil spills from the D-6 platform. The latter was done daily for operational correction of the action plan for accident elimination at the D-6 and ecological risk assessment (oil pollution of the sea and the Curonian Spit). Probability of the oil spill drift directed to the Curonian Spit equals to 67%, but only in a half of these cases oil spills could reach the coast during 48 h after an accidental release of 10 m3 of oil.

Multisensor satellite monitoring of seawater state and oil pollution in the northeastern coastal zone of the Black Sea

A new approach aimed at a better understanding of the state of pollution of the Black Sea coastal zone is suggested. It consists of the combined use of all available quasi‐concurrent satellite information (NOAA AVHRR, TOPEX/Poseidon, Jason‐1, Terra/Aqua MODIS, Envisat ASAR, ERS‐2 SAR and QuikSCAT) and was first applied during an operational seawater monitoring campaign in the coastal zone of the northeastern Black Sea conducted in 2006. The monitoring is based on daily receiving, processing and analysis of data different in nature (microwave radar images, optical and infrared data), resolution and surface coverage. These data allow us to retrieve information on seawater pollution, sea surface and air–sea boundary layer conditions, seawater temperature and suspended matter distributions, chlorophyll‐a concentration, mesoscale water dynamics, near‐surface wind, and surface wave fields. Such an approach helps in oil spill detection with synthetic aperture radar (SAR), especially in distinguishing oil slicks from look‐alikes. The focus is on coastal seawater circulation mechanisms and their impact on the evolution of pollutants.

Multi-sensor survey of seasonal variability in coastal eddy and internal wave signatures in the north-eastern Black Sea

In this paper the remote sensing satellite sensor data (obtained by Envisat Advanced Synthetic Aperture Radar (ASAR), Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS), and National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) instruments) is used to study coastal dynamics of the north-eastern Black Sea. Occurrence, evolution and drift of small-scale eddies in coastal waters are investigated. Seasonal variability of their manifestations is established. Instances of surface manifestations of non-tidal internal waves (IW) are discovered. The main finding was that practically all cases of IW manifestations were observed in the vicinity of mesoscale sea eddy structures or hydrological fronts. The joint analysis of data from different sensors was performed to reveal specific conditions leading to the intensification of wave processes and to their manifestation in radar imagery as well as to determine possible sources of the IW generation.

Satellite Monitoring of Oil Pollution in the Southeastern Baltic Sea

The chapter shows the examples and results of satellite monitoring of oil pollution in the Southeastern Baltic Sea obtained in 2004–2012. The beginning of this work was initiated by “LUKOIL-Kaliningradmorneft” in relation to installation of the D-6 offshore platform and production of oil in spring 2004. The results clearly show that the Southeastern Baltic Sea is highly polluted by oil products, and that this is related to intense shipping activities in the region. No pollution in the vicinity of the D-6 oil platform was detected during these years. Interannual variability of the number and surface of oil spills, as well as their seasonal and diurnal variability is discussed. The problem of transboundary oil pollution transport between EEZs of Poland, Russia, and Lithuania is highlighted.

Satellite Monitoring of the Nord Stream Gas Pipeline Construction in the Gulf of Finland

This chapter explains the need for comprehensive satellite environmental monitoring of the Nord Stream gas pipeline construction in the Baltic Sea, including monitoring of oil pollution, the spread of suspended matter, algal bloom, and thermal effects at the sea surface. Examples of the different types of the observed contamination along the pipeline route long before the pipeline construction are shown. This chapter is focused on the results of oil pollution monitoring during the pipeline construction, and also shows the results concerning the satellite monitoring of ice cover, suspended matter, algal bloom, and thermal effects on the sea surface in the Gulf of Finland.

Satellite Survey of Inner Seas: Oil Pollution in the Black and Caspian Seas

The paper discusses our studies of oil pollution in the Black and Caspian Seas. The research was based on a multi-sensor approach on satellite survey data. A combined analysis of oil film signatures in satellite synthetic aperture radar (SAR) and optical imagery was performed. Maps of oil spills detected in satellite imagery of the whole aquatic area of the Black Sea and the Middle and the Southern Caspian Sea are created. Areas of the heaviest pollution are outlined. It is shown that the main types of sea surface oil pollution are ship discharges and natural marine hydrocarbon seepages. For each type of pollution and each sea, regions of regular pollution occurrence were determined, polluted areas were estimated, and specific manifestation features were revealed. Long-term observations demonstrate that in recent years, illegal wastewater discharges into the Black Sea have become very common, which raises serious environmental issues. Manifestations of seabed hydrocarbon seepages were also detected in the Black Sea, primarily in its eastern part. The patterns of surface oil pollution of the Caspian Sea differ considerably from those observed in the Black Sea. They are largely determined by presence of big seabed oil and gas deposits. The dependence of surface oil SAR signatures on wind/wave conditions is discussed. The impact of dynamic and circulation processes on oil films drift and spread is investigated. A large amount of the data available allowed us to make some generalizations and obtain statistically significant results on spatial and temporal variability of various surface film manifestations.The examples and numerical data we provide on ship spills and seabed seepages reflect the influence of the pollution on the sea environment.

Investigation of fine spatial structure of currents and submesoscale eddies based on satellite radar data and concurrent acoustic measurements

Satellite high-resolution radar data from Envisat ASAR, RADARSAT-2 and TerraSAR-X sensors are used for the detection and investigation of fine structure of currents and submesoscale eddies. The fine structure of sea currents is manifested in radar images as quasiperiodic slick strips of a horizontal scale from tens of meters to several kilometers. The strips are typically elongated along the currents apparently indicating their jet character and intermittence. The focus is on filamentary slick bands involved into small scale vortical processes and allowing estimation of spatial characteristics of submesoscale eddies based on their SAR signatures. Submesoscale or eddies with diameters of less than Rossby radius of deformation could hardly be investigated by traditional oceanographic means due to spontaneity of their appearance, nonstationarity and short lifetimes. Sources of their generation are still not well known. A large archive of satellite data accumulated during 1999-2011 over different parts of the Black, Baltic and Caspian Seas has been analyzed in order to search, systemize and reveal mechanisms of formation and evolution of small scale eddy structures in these areas. Atmospheric and hydrological fronts and current instability have been found to play a significant role in submesoscale eddies generation. Subsatellite measurements using acoustic Doppler profiler (ADCP) have been performed aimed at verification and adjustment of the results obtained based on satellite radar data. The formation and drift of a near-shore submesoscale anticyclonic eddies of 5-7 km in diameter were observed.

SAR observations of typical phenomena in the Black Sea shore area

Summer/autumn experiments conducted for the past four years by Space Research Institute RAS near Ghelendzhik, Black Sea shore, allowed to closely monitor sea and atmosphere dynamics in the region. Over 35 ERS-2 SAR images obtained exhibit large variety of important phenomena: atmospheric and oceanic fronts pollution and other slicks, atmospheric convection, vortices, lee patterns, etc. Available extensive data covering all-year sea state, NOAA data and hydrometeorological condition help to adequately interpret SAR signatures. The focus is on three phenomena: lee structures in the atmosphere downwind from the coastal ridge and their dependencies of their growth rate and spatial characteristics on wind speed and direction and medium stratification; vortices which are a frequent occasion in the 100-km coastal zone where north-western current predominates; considerable oil pollution of the coast registered in the end of July 2002.

Effect of Wind and Hydrographic Conditions on the Transport of Vistula Lagoon Waters Into the Baltic Sea: Results of a Combined Experiment

The influence of wind and hydrodynamic processes on the spreading of turbid waters from the Vistula Lagoon into the Baltic Sea was studied. Our research is based on joint analyses of remote sensing data and those from concurrent in situ measurements of the three-dimensional structure of the outflow. A strong difference in the water optical properties of the Baltic Sea and the Vistula Lagoon caused by an intense summer bloom of cyanobacteria allowed studies of the evolution and transformation of the outflow in mid-July-early August 2014 using Ocean Color satellite data. Our in situ measurements revealed that waters from the Vistula Lagoon were exclusively present in the upper water layer. The study was conducted under various wind and, therefore, under different upwelling/downwelling conditions, thereby determining different patterns of wind-driven currents, which enabled us to assess their impact on the propagation of the lagoon outflow. One of these patterns was reaching to the south, along the Vistula Spit, and another one reaching to the north, along the Sambia Peninsula. We show that the main spreading direction of the plume strongly coincides with that of wind-driven currents. However, if vortical structures are present in the Bay of Gdańsk, they also affect the plume transformation, and that should be taken into account when the propagation of water pollution is forecasted.

Dynamic Phenomena in the Coastal Waters of the North-Eastern Black Sea Retrieved from Satellite Data

Our paper discusses satellite observations data for the north-eastern Black Sea. Our study is based on remote sensing satellite data obtained by ERS-2 SAR, Envisat ASAR, Terra and Aqua MODIS, and NOAA AVHRR instruments. The data from different sensors was analyzed jointly to investigate coastal water circulation and in particular the occurrence, evolution and drift of vortical structures. One result of our investigation included a discovery of surface manifestations of non-tidal internal waves generated in the vicinities of sea eddy structures. Another finding was a seasonal variability of vortex structures in the coastal zone.