Auswahl der wissenschaftlichen Literatur zum Thema „Coastal Gas Link (CGL)“

Abstract. A model of iodine chemistry in the marine boundary layer (MBL) has been used to investigate the impact of daytime coastal emissions of molecular iodine (I2). The model contains a full treatment of gas-phase iodine chemistry, combined with a description of the nucleation and growth, by condensation and coagulation, of iodine oxide nano-particles. In-situ measurements of coastal emissions of I2 made by the broadband cavity ring-down spectroscopy (BBCRDS) and inductively coupled plasma-mass spectrometry (ICP/MS) techniques are presented and compared to long path differential optical absorption spectroscopy (DOAS) observations of I2 at Mace Head, Ireland. Simultaneous measurements of enhanced I2 emissions and particle bursts show that I2 is almost certainly the main precursor of new particles at this coastal location. The ratio of IO to I2 predicted by the model indicates that the iodine species observed by the DOAS are concentrated over a short distance (about 8% of the 4.2 km light path) consistent with the intertidal zone, bringing them into good agreement with the I2 measurements made by the two in-situ techniques. The model is then used to investigate the effect of iodine emission on ozone depletion, and the production of new particles and their evolution to form stable cloud condensation nuclei (CCN).

Abstract. A model of iodine chemistry in the marine boundary layer (MBL) has been used to investigate the impact of daytime coastal emissions of molecular iodine (I2). The model contains a full treatment of gas-phase iodine chemistry, combined with a description of the nucleation and growth, by condensation and coagulation, of iodine oxide nano-particles. In-situ measurements of coastal emissions of I2 made by the broadband cavity ring-down spectroscopy (BBCRDS) and inductively coupled plasma-mass spectrometry (ICP/MS) techniques are presented and compared to long path differential optical absorption spectroscopy (DOAS) observations of I2 at Mace Head, Ireland. Simultaneous measurements of enhanced I2 emissions and particle bursts show that I2 is almost certainly the main precursor of new particles at this coastal location. The ratio of IO to I2 predicted by the model indicates that the iodine species observed by the DOAS are concentrated over a short distance (about 8% of the 4.2 km light path) consistent with the intertidal zone, bringing them into good agreement with the I2 measurements made by the two in-situ techniques. The model is then used to investigate the effect of iodine emission on ozone depletion, and the production of new particles and their evolution to form stable cloud condensation nuclei (CCN).

The Bacton Sandscaping scheme is a large-scale beach nourishment, designed to protect the Bacton Gas Terminal from cliff and beach erosion while also reducing flood and erosion risk to the communities of Bacton and Walcott, buying the time they need for adaptation to coastal change. The scheme was inspired by the even larger Dutch Zandmotor project, translating the concept to the different geography and governance setting of the UK - it can be seen as the Zandmotor's 'little nephew'. The term 'Sandscaping' was introduced to illustrate the large-scale and ambitious nature of the concept: work at a large scale, designing to work with natural processes and to achieve multiple objectives.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/FA3DjdCgKrk

Environmental Context.Bursts of ultra-fine particles (diameter < 10 nm) in the daytime coastal marine boundary layer at low tide coincide with the observation of iodine oxide radicals. The detection of iodine in the particles suggests a direct link between the biogenic emission of iodine-containing vapours and subsequent particle nucleation and growth. These coastal aerosols are therefore most likely iodine oxide polymers. However, the reaction pathways leading to the homogeneous nucleation of these particles are currently an area of uncertainty, as is their final composition. These ultra-fine particles are potentially important as a source of cloud condensation nuclei, and as a major pathway for enriching iodine in marine aerosol. Abstract.Iodine oxide nanoparticles were generated photochemically from I2 in the presence of O3, and their morphology and composition analyzed by transmission electron microscopy (TEM). The particles exhibit fractal morphologies consistent with agglomerative coagulation, and have an O/I ratio of 2.45 ± 0.08, indicating that they are composed of I2O5. Quantum calculations show that gas-phase I2O5 could be formed by a series of exothermic reactions involving the oxidation of I2O2, I2O3 and I2O4 by O3. In order to form pure I2O5 particles, modelling calculations indicate that the rate coefficients for these reactions probably need to be faster than 6 × 10−13 cm3 molecule−1 s−1 at 295 K. Applying this model to the atmosphere shows that ultra-fine iodine oxide particles formed in the coastal marine boundary layer would then consist of I2O5.

In a changing climate, understanding how soil hydrology impacts greenhouse gas dynamics will be important for the future management of the soils in the forests on the Canadian Pacific west coast. In a laboratory study, the impact of soil hydrology on potential net methane (CH4) exchange rates and the abundance of methanotrophs (CH4oxidation) and methanogens (CH4production) in upland and water-saturated wet soils were investigated. CH4oxidation and production rates were highest in the wet soils, which corresponded to higher numbers of methanotrophs and methanogens, indicating a link between the microbial abundance and CH4exchange rates. Also, CH4production was induced in the upland soils, indicating the presence of methanogens. The optimum soil moisture content for CH4oxidation was highest in upland soils and the wet soils sustained higher CH4oxidation rates over a broader range of soil moisture. These results underline the importance of the soil hydrological controls of CH4oxidation in contrasting soils and forest types, which deserves further attention in field-based studies.

The problem of global warming is becoming more and more serious. N2O is a potent greenhouse gas. Most current studies on dissolved N2O concentration have focused on inland freshwater and seawater while paying less attention to coastal agricultural catchment areas. The coastal agricultural catchment area is the link between the farmland ecosystem and the aquatic ecosystem, which is shallow in water depth. Moreover, due to the high salt content and obvious periodic change, it is highly sensitive to environmental changes and human activities and has strong potential for N2O emission. Therefore, it is of great significance to understand the characteristics of the changes in the dissolved N2O concentration in the shallow-water ecosystem under the saline-alkali environment of the coastal reclamation area and to identify the main controlling factors. The soil of Yudong reclamation area in Rudong County, Jiangsu Province was collected to carry out the submerged cultivation experiment. In order to simulate the saline-alkali situation of the coastal reclamation area, four salt gradients (S1–S4), four alkali gradients (A1–A4), and three levels of exogenous nitrogen concentration (N1–N3). In addition, the experiment set a control treatment (CK) without salt and alkali addition. After 2 weeks of cultivation in a shallow water layer of about 5 cm, the dissolved N2O concentration and its influencing factors were measured and analyzed by collecting the overlying water sample and sediment after 24 h of fertilization. The results showed that changes in the saline-alkali environment in shallow-water ecosystems significantly affected the changes in dissolved N2O concentration. The saline-alkali indicators (EC and pH of the overlying water and sediment), DO of the overlying water, and the microbial genes nirS, nirK, and nosZ were the key influencing factors of N2O production in shallow-water systems. The correlation between nirS gene abundance and the dissolved N2O concentration was the highest. The BP neural network model can be used to simulate and predict the dissolved N2O concentration in overlying water under saline-alkali environment. Based on the experimental results, this study can provide a scientific basis for understanding the nitrogen cycling process in shallow-water ecosystems in the coastal reclamation area, improving the absorption of non-point-source nitrogen and reducing N2O emissions in shallow-water wetlands.

AbstractThree ice cores drilled in the central part of the Antarctic continent extend back to the last glacial period: one from West Antarctica (Byrd) and two from East Antarctica (Vostok and Dome C). This period is also partly covered by a few cores from the coastal areas. In these cores, climatic information is mostly derived from the isotopic profiles (δD or δ18O) from which surface temperature and, more indirectly, precipitation rate can be estimated. The main objective has been to compare thoroughly the three deep ice cores for the main part of the last glacial period (from ca. 65,000–15,000 yr B.P.). The time scales have been examined in detail and a new 40,000 yr chronology for the Dome C core adopted. Special emphasis is placed on the link between the concentration of 10Be and past accumulation changes and on the use of peaks in the concentration of this cosmogenic isotope as stratigraphic markers. Elevation changes of the ice sheet, derived from gas content and isotopic data, bear directly on interpretations of past temperature and precipitation rate changes.

Environmental context Halocarbons are trace gases important in atmospheric ozone chemistry whose biogenic production – among other factors – depends on light-induced stress of marine algae. Several studies have confirmed this effect in laboratory experiments but knowledge in natural systems remains sparse. In mesocosm experiments, which are a link between field and laboratory studies, we observed that the influence of natural levels of ultraviolet radiation on halocarbon dynamics in the marine surface waters was either insignificant or concealed by the complex interactions in the natural systems. Abstract The aim of the present study was to evaluate the influence of different light quality, especially ultraviolet radiation (UVR), on the dynamics of volatile halogenated organic compounds (VHOCs) at the sea surface. Short term experiments were conducted with floating gas-tight mesocosms of different optical qualities. Six halocarbons (CH3I, CHCl3, CH2Br2, CH2ClI, CHBr3 and CH2I2), known to be produced by phytoplankton, together with a variety of biological and environmental variables were measured in the coastal southern Baltic Sea and in the Raunefjord (North Sea). These experiments showed that ambient levels of UVR have no significant influence on VHOC dynamics in the natural systems. We attribute it to the low radiation doses that phytoplankton cells receive in a normal turbulent surface mixed layer. The VHOC concentrations were influenced by their production and removal processes, but they were not correlated with biological or environmental parameters investigated. Diatoms were most likely the dominant biogenic source of VHOCs in the Baltic Sea experiment, whereas in the Raunefjord experiment macroalgae probably contributed strongly to the production of VHOCs. The variable stable carbon isotope signatures (δ13C values) of bromoform (CHBr3) also indicate that different autotrophic organisms were responsible for CHBr3 production in the two coastal environments. In the Raunefjord, despite strong daily variations in CHBr3 concentration, the carbon isotopic ratio was fairly stable with a mean value of –26‰. During the declining spring phytoplankton bloom in the Baltic Sea, the δ13C values of CHBr3 were enriched in 13C and showed noticeable diurnal changes (–12‰ ±4). These results show that isotope signature analysis is a useful tool to study both the origin and dynamics of VHOCs in natural systems.

This study aimed to investigate the volatile flavor compounds and tastes of six kinds of sauced pork from the southwest and eastern coastal areas of China using gas chromatography–ion mobility spectroscopy (GC-IMS) combined with an electronic nose (E-nose) and electronic tongue (E-tongue). The results showed that the combined use of the E-nose and E-tongue could effectively identify different kinds of sauced pork. A total of 52 volatile flavor compounds were identified, with aldehydes being the main flavor compounds in sauced pork. The relative odor activity value (ROAV) showed that seven key volatile compounds, including 2-methylbutanal, 2-ethyl-3, 5-dimethylpyrazine, 3-octanone, ethyl 3-methylbutanoate, dimethyl disulfide, 2,3-butanedione, and heptane, contributed the most to the flavor of sauced pork (ROAV ≥1). Multivariate data analysis showed that 13 volatile compounds with the variable importance in projection (VIP) values > 1 could be used as flavor markers to distinguish six kinds of sauced pork. Pearson correlation analysis revealed a significant link between the E-nose sensor and alcohols, aldehydes, terpenes, esters, and hetero-cycle compounds. The results of the current study provide insights into the volatile flavor compounds and tastes of sauced pork. Additionally, intelligent sensory technologies can be a promising tool for discriminating different types of sauced pork.

Abstract. Measurements of individual NOy components were carried out at Halley station in coastal Antarctica. The measurements were made as part of the CHABLIS campaign (Chemistry of the Antarctic Boundary Layer and the Interface with Snow) and cover over half a year, from austral winter 2004 through to austral summer 2005. They are the longest duration and most extensive NOy budget study carried out to date in polar regions. Results show clear dominance of organic NOy compounds (PAN and MeONO2) during the winter months, with low concentrations of inorganic NOy, but a reversal of this situation towards summer when the balance shifts in favour of inorganic NOy. Multi-seasonal measurements of surface snow nitrate correlate strongly with inorganic NOy species. One case study in August suggested that particulate nitrate was the dominant source of nitrate to the snowpack, but this was not the consistent picture throughout the measurement period. An analysis of NOx production rates showed that emissions of NOx from the snowpack dominate over gas-phase sources of "new NOx", suggesting that, for certain periods in the past, the flux of NOx into the boundary layer can be calculated from ice core nitrate data.

Abstract This chapter discusses the chemistry of dissolved oxygen (DO), which plays a critical role in regulating the redox chemistry of natural waters. DO concentrations are controlled by a range of chemical and biological redox processes and by physical factors that affect O2 solubility and transfer rates across the air-water interface. The importance of biological processes in controlling DO conditions in aquatic systems is indicative of a link to nutrient cycle processes described in Chapter 19. Spatial and temporal patterns of DO concentrations in lakes and rivers, and the widespread phenomenon of hypoxia in coastal waters, are explained in the context of major driving forces: solubility, gas-transfer kinetics, and nutrient inputs from land. Analysis of DO by the classic Winkler titration is described as an archetypal redox titration. Chemical principles underlying DO analysis by now more widely used instrumental methods (electrodes and optodes) also are explained.

Two full scale burst tests for the assessment of different crack arrestor designs were carried out on the pipes that will be used in the Coastal GasLink (CGL) Pipeline project. The tests supported by LNG Canada and TransCanada Technology Management Program were conducted at the Spadeadam test site of DNV GL, United Kingdom (UK), on 1219 mm (48 inch) outside diameter CSA Z245.1 Category II Grade 550 pipe at a nominal pressure of 13.38 MPa (1,940 psig) with 80% SMYS and temperature of −5°C, and with a gas representative of the richest gas envisaged for transport in the CGL pipeline project. The reservoirs are spaced with a gap between the reservoir ends of approximately 130 m, where the test section, comprising eleven pipe lengths and a tie-in pup, was installed. The centre of the test section consisted of an 18.5 mm thick low toughness initiation pipe. The remaining pipes were referenced as 1E to 5E in the easterly direction and similarly 1W to 5W in the westerly direction. The propagation pipes (1E and 1W) with 18.5 mm wall thickness, used to establish steady-state propagation, were located immediately either side of the central initiation pipe. For the first test, two crack arrestor pipes with 29.6 mm wall thickness were installed adjacent to the propagation pipes in the west and east directions, with a lead-in transition of 18.5 mm wall thickness for a distance of 130 mm then a 4:1 taper running back to the full pipe wall thickness. To the east, the first crack arrestor pipe had an average Charpy Vee-notch (CVN) energy of 246 J and to the west it had an average CVN energy of 341 J at the inboard end. In both directions, the fracture propagated from the initiation pipe, through the propagation pipes (1E/1W) before arresting in the first 29.6 mm thick crack arrestor pipes (2E/2W). In both directions, the arrest resulted in the fracture turning at the toe of the tapered transition on the front end of crack arrestor pipes 2E and 2W. The pipe arrangement for the second test was similar to the first one. In the east direction, in order to optimize crack arrestor design, two 24.7 mm wall thickness pipes replaced the 29.6 mm pipes which were used in the first test. In the west direction, the test section contained four 18.5 mm wall thickness test pipes arranged with a progressively increasing Charpy energy, up to 452 J. A low toughness, 18.5 mm thick pipe (5W), with a 1.8 m long Clock Spring® crack arrestor completed the test section. To the east, the fracture propagated from the initiation pipe through pipe 1E before arresting near the inboard end of the crack arrestor pipe 2E. In the west direction, the fracture was observed to run through all four of the pipes arranged with increasing CVN energy, before being arrested by the Clock Spring® crack arrestor fitted to the fifth pipe.

Committee Mandate Concern for investigation and applications of ships, offshore structures and engineering equipment for ocean space utilization in the context of marine resource exploitation, human habitation and other marine infrastructure. Focus should be given to fluid-structure interaction associated with large marine structures and structural flexibility. Due consideration should be given to the comparison of modelling approaches, existing and emerging guidance & best practices. Introduction In the light of rising sea level, scarcity of land-based resources and increasingly populated coastal areas, interest of project developers and countries turns towards the ocean, exploring the possibilities of utilizing this space for various purposes. With the oceans covering roughly 70% of the Earth’s surface and more than half of the world’s population clustered in coastal areas, the oceans are a natural direction to turn to. Ocean Space Utilization (OSU), i.e., the use of ocean waters and/or the seabed for human activities, is by no means new. Shipping and fishing in ocean waters date back millennia. During the last century, aquaculture of seafood production developed into a global industry. Also, the seabed has provided minerals (mostly sand) as building material. Recently, the marine mining industry experienced a development from traditional sand dredging to deep sea mining for precious or rare mineral resources. The offshore oil and gas industry developed from first wooden platforms in the shallow coastal waters of the Gulf of Mexico to Floating Production Storage and Offloading systems and subsea equipment in more than 2000 m water depth offshore Brazil. More recently, the wind energy industry followed the steps of the oil and gas industry and moved from land-based installations first to shallow coastal waters with bottom-founded wind turbines and now starts developing offshore floating wind turbines for larger water depth and greater distances to shore. Marine Renewable Energies (MRE) including Wave Energy Converters (WEC), flow turbines for electricity production from ocean or tidal currents, and Ocean Thermal Energy Conversion (OTEC) are emerging. Another recent form of renewable energy production on the ocean are Offshore Floating Photovoltaic (OFPV) Installations (Karpouzoglou et al., 2020; Trapani & Millar, 2016; Trapani & Redón Santafé, 2015). Furthermore, marine infrastructure projects of floating airports (Suzuki, 2005), floating bridges and submerged tunnels (Moan & Eidem, 2020; Watanabe et al., 2015), floating oil storage terminals (Ueda, 2015; Zhang et al., 2020), floating logistics hubs/ports (Waals et al., 2018), a floating event stage (Koh and Lim, 2015), as well as even entire floating cities (Callebaut, 2015) are discussed in the literature. Eventually, recreational use and ocean research also belong to the broad field of Ocean Space Utilization. As an inventory of Ocean Space Utilization projects, this committee gathered as many OSU projects as possible in various stages (from concept study to commercial project) and from various fields in a project atlas based on Google maps. Offshore oil and gas projects are excluded from the atlas to prevent overloading it. Figure 1.1 shows a screenshot of the project atlas with a global overview of all projects. The projects can be grouped and color-coded by OSU field or by project status as shown in the two columns on the right of the figure. At the time of writing, this project atlas contained 235 projects. Even without offshore oil and gas projects, the energy field, comprising mainly offshore wind farms, dominates the list with 90 projects. Two other large fields of OSU are food production, i.e., mainly (offshore) aquaculture with 46 projects, and infrastructure projects (35) like floating bridges and airports. From the project list by field, it is apparent that there are many projects associated with more than one field. This signifies the new trend of multi-use ocean space utilization. An example for this multi-use is mussel farming within an offshore wind farm (see Edulis project in food & energy field). Regarding the project stage, the project entries range from mere concepts and research projects to fully operational structures. The database behind this project atlas contains more information on the individual projects with details on the field (use), project name and location, coordinates, the associated institution as well as a link for further information.

This Coastal and Hydraulics Engineering Technical Note (CHETN) describes a method for evaluating the received coverage from Automatic Identification System (AIS) shoreside sites along the Missouri River managed by the US Army Corps of Engineers (USACE) Lock Operations Management Application (LOMA), and presents the results of that analysis. The purpose is to identify AIS coverage gaps in the current system. Reception of AIS transmissions between shore-based transceivers and vessels is generally line-of-sight between the vessel and the AIS site antenna. However, signal reception may be affected by factors such as the distance and terrain between the vessel and the transceiver site, quality of the transceiver installation, state of the equipment either aboard the vessel or at the shore transceiver station, and atmospheric phenomena. Quantifying coverage gaps along the inland waterways system can inform research that uses AIS data, provide information on the performance of the AIS network, and provide guidance for efforts to address coverage gaps to improve navigation safety. In autumn 2020, severe shoaling was occurring on the Missouri River. As the shoals were identified, the Kansas City District requested the LOMA system transmit AIS Aid to Navigation (AtoN) to mark the shoals in several critical areas. However, vessel pilots sometimes reported that they were not receiving the AIS AtoN being transmitted. At the request of the Kansas City District, the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), conducted a coverage analysis using data collected from the LOMA AIS transceivers in the area to determine if there were coverage issues and their extent and to aid in determining the best means of addressing any coverage gaps.