Assessment of the use of space technology in the monitoring of oil spills and ocean pollution: Technical volume. Executive summary

The potential of space systems and technology for detecting and monitoring ocean oil spills and waste pollution was assessed as well as the impact of this application on communication and data handling systems. Agencies charged with responsibilities in this area were identified and their measurement requirements were ascertained in order to determine the spatial resolution needed to characterize operational and accidental discharges. Microwave and optical sensors and sensing techniques were evaluated as candidate system elements. Capabilities are described for the following: synthetic aperture radar, microwave scatterometer, passive microwave radiometer, microwave altimeter, electro-optical sensors currently used in airborne detection, existing space-based optical sensors, the thematic mapper, and the pointable optical linear array

Design of a flexible containment system for deep ocean oil spills

Thesis (S.M.)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 153-155).BP needed almost 3 months to cap the Deepwater Horizon spill; improved response techniques are needed for the future. This work presents the design and deployment plan for a new type of containment system that captures the vast majority of hydrocarbons exiting the wellhead. The structure is lightweight, flexible and modular, using a passively induced chimney affect as its working principle. It is modular to create one design that fits any number and size of wells. Modularity comes from 100m sections of thin Kevlar fabric, forming a cylinder that starts several meters above the seabed and ends several meters below the sea surface. The system is stored onshore mostly assembled until needed. The 3m-diameter shroud induces a flow that dilutes the gas to avoid hydrate formation. Yet the velocity is sufficiently small for gas to dissolve, reducing surface gas concentrations below workers' safety thresholds. The chimney effect causes a pressure differential over the material; reinforcement ribs are required to keep the system from collapsing inward. At the shroud top, the jet enters a containment pen, which is loosely attached to the shroud allowing it to ride the waves in heave, but constraining roll, pitch and yaw. The pen diameter allows oil to separate from the water; a skimmer weir in the pen collects almost pure oil and pumps it to a tanker. An air can at the shroud top provides pre-tension that restrains lateral deflections due to a uniform current, and helps reduce the collapse due to the pressure differential. The deflection and collapse are calculated for a uniform current using catenary equations. The results are used to verify the applicability of OrcaFlex, software commonly used by the offshore industry, which is then used to confirm the systems ability to satisfy design requirements under realistic conditions (a sea spectrum and non-uniform current). The 'one design fits all' objective is tested by initially designing the system for a moderate size reference well, and then scaling it up (with minor modifications) to fit the Macondo well. The results confirm that one design of the system can contain spills of moderate size in addition to those similar to the Deepwater Horizon.by Natasha Maas.S.M

Literature Review: Review of Recent Developments of Bioremediation Applications to Ocean Oil Spills

This paper explores recent developments in microbial remediation, specifically oil-degrading bacteria, and its potential use in ocean oil spills. Marine oil spills are a growing issue worldwide, due to its hazardous impact on both public and environmental welfare. Conventional oil spill management practices are inefficient, since significant amounts of oil remain in the water post-treatment. A possibly efficient and environmentally friendly solution is bioremediation, also known as microbial remediation. Bioremediation is a form of microbial enhanced oil recovery (MEOR), which is a biotechnological process that utilizes microorganisms to break down organic compounds, such as oil. By use of oil degrading bacteria, bioremediation applications may prove to be a feasible method in oil spill management. In this review, a systematic approach was used to find literature that could be analyzed to find which bacterial strains and supplementations would improve bioremediation as a method for mitigating ocean oil spills. It was concluded that certain bacterial strains are effective at degrading oil, given that certain metabolic and nutrient conditions are provided. Bacterial strains capable of decontaminating marine oil spills include Mycobacterium vanbaalenii, and Alcanivorax borkumensis, and Cycloclasticus, along with several others. Algae and dispersants used in conjunction with marine bacteria enhanced oil-degradation rates. However, more studies are needed to further investigate more potential bacterial strains capable of oil-degradation, and if other supplementations oil spill recovery in oil spills.https://digitalscholarship.unlv.edu/durep_posters/1044/thumbnail.jp

Fractal approach of turbulent dispersion

There are several techniques suitable for measuring and modelling dispersion from scalar or velocity-field measurements in a turbulent flow. Each of these has peculiar features and sometimes, even different scaling, and a careful choice has to be made depending on the kind of information available and needed. A useful way to investigate diffusion is to make use of the fractal and multifractal information that ocean and atmospheric flows provide. Here we present some fractal based techniques, where the velocity and scalar fields are related to the spectral spatial information that they provide and are used to predict diffusivity and mixing.In addition an Eulerian description can be obtained by interpolation from Lagrangian information, which is much easier to model via Kinematic Simulation or synthetic turbulence type models, because the detail velocity field is eventually sampled in a random statistical way in the whole domain during their time evolution. It is not possible to get reliable Lagrangian information using PIV since the transformation from the Eulerian description to the Lagrangian one implies an integration in time of the velocity field, especially when considering phenomena that show high sensitivity to initial conditions (turbulent flows). We show some examples of oil spill dispersion in the ocean surface and discuss several multifractal and scaling approaches.Peer ReviewedPostprint (published version

Characteristics of the Bohai Sea oil spill and its impacton the Bohai Sea ecosystem

In this paper, ENVISAT ASAR data and the Estuary, Coastal and Ocean Model was&nbsp; used to analyze and compare characteristics of the Bohai Sea oil spill. The oil&nbsp; slicks have spread from the point of the oil spill to the east and north-western&nbsp; Bohai Sea. We make a comparison between the changes caused by the oil spill on&nbsp; the chlorophyll concentration and the sea surface temperature using MODIS data,&nbsp; which can be used to analyze the effect of the oil spill on the Bohai Sea&nbsp; ecosystem. We found that the Bohai Sea oil spill caused abnormal chlorophyll&nbsp; concentration distributions and red tide nearby area of oil spill.</span

Challenges and opportunities in understanding microbial communities with metagenome assembly (accompanied by IPython Notebook tutorial)

Metagenomic investigations hold great promise for informing the genetics, physiology, and ecology of environmental microorganisms. Current challenges for metagenomic analysis are related to our ability to connect the dots between sequencing reads, their population of origin, and their encoding functions. Assembly-based methods reduce dataset size by extending overlapping reads into larger contiguous sequences (contigs), providing contextual information for genetic sequences that does not rely on existing references. These methods, however, tend to be computationally intensive and are again challenged by sequencing errors as well as by genomic repeats While numerous tools have been developed based on these methodological concepts, they present confounding choices and training requirements to metagenomic investigators. To help with accessibility to assembly tools, this review also includes an IPython Notebook metagenomic assembly tutorial. This tutorial has instructions for execution any operating system using Amazon Elastic Cloud Compute and guides users through downloading, assembly, and mapping reads to contigs of a mock microbiome metagenome. Despite its challenges, metagenomic analysis has already revealed novel insights into many environments on Earth. As software, training, and data continue to emerge, metagenomic data access and its discoveries will to grow

Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 38 (2011): L09602, doi:10.1029/2011GL047174.Hydrocarbons released following the Deepwater Horizon (DH) blowout were found in deep, subsurface horizontal intrusions, yet there has been little discussion about how these intrusions formed. We have combined measured (or estimated) observations from the DH release with empirical relationships developed from previous lab experiments to identify the mechanisms responsible for intrusion formation and to characterize the DH plume. Results indicate that the intrusions originate from a stratification-dominated multiphase plume characterized by multiple subsurface intrusions containing dissolved gas and oil along with small droplets of liquid oil. Unlike earlier lab measurements, where the potential density in ambient water decreased linearly with elevation, at the DH site it varied quadratically. We have modified our method for estimating intrusion elevation under these conditions and the resulting estimates agree with observations that the majority of the hydrocarbons were found between 800 and 1200 m.Funding for this project was supported by the National Science Foundation under RAPID grants CBET‐1045831, CBET‐1046890, and OCE‐1048976, and by the U. S. Geological Survey, Coastal and Marine Geology Program

Proceedings of the Workshop on Government Oil Spill Modeling

Oil spill model users and modelers were brought together for the purpose of fostering joint communication and increasing understanding of mutual problems. The workshop concentrated on defining user needs, presentations on ongoing modeling programs, and discussions of supporting research for these modeling efforts. Specific user recommendations include the development of an oil spill model user library which identifies and describes available models. The development of models for the long-term fate and effect of spilled oil was examined