Background: Autoimmune diseases are more prevalent in women than in men, and such a disparity als... more Background: Autoimmune diseases are more prevalent in women than in men, and such a disparity also exists in animal models. In our studies with the mouse model of experimental autoimmune encephalomyelitis (EAE) induced with myelin proteolipid protein 139-151 (PLP) for multiple sclerosis, gender differences are well documented, in that only female, but not male, SJL mice show chronic relapsingremitting paralysis. Since EAE is typically mediated by CD4 T cells, we tested a hypothesis that the generation and expansion of antigen-specific CD4 T cells might be different between genders. Methods and findings: First, by creating a newer and more sensitive version of major histocompatibility complex class II tetramers called dextramers, we noted no differences in the generation of PLP-specific T cells in the peripheral repertoires of male and female SJL mice. Second, comparable numbers of PLP-specific T cells were found to be infiltrated into the brains of both genders as verified by flow cytometric analysis. Third, evaluation of molecules that positively or negatively regulate the expansion of effector T cells revealed that expression of cytotoxic T-lymphocyte associated protein 4 was tended to be more in the T cells that infiltrate into the brains of male than female mice. Finally, we analyzed the proteomic profiles in PLP 139-151specific T cells to identify additional novel molecules that may potentially contribute to the gender-disparity in the development of central nervous system autoimmunity. In conjunction with tandem mass spectrometric analysis and ingenuity pathway analysis, we have identified a panel of proteins found to be expressed gender dependently, suggesting that they can be regulated by sex steroids. Conclusions: Our data revealed expression of proteins that can potentially play a role in the development of diseases of multiple organs such as the central nervous system and cardiovascular system including cancers.
R-C. (2015). Assessing the environmental fate of selected polybrominated diphenyl ethers in the r... more R-C. (2015). Assessing the environmental fate of selected polybrominated diphenyl ethers in the region surrounding the Zhuoshui River of Taiwan based on an Equilibrium Constant fugacity model.
The Beibu Gulf Economic Rim of China is a key economic region in western China as demonstrated by... more The Beibu Gulf Economic Rim of China is a key economic region in western China as demonstrated by the "Beibu Gulf Cities Development Project" (2017) that plans to build a "Blue Livable Gulf" to balance environmental protection while providing sustainable economic development. This region has significant energy needs and is predicted to exhibit rapid growth in the future. By means of meteorological observations located at seven islands, a comprehensive statistical analysis on wind energy potential in the northern coastal part of the Beibu Gulf is conducted in this study. Specifically, wind speed, Weibull parameters, wind power density, as well as wind directions on various timescales are analyzed. The analysis shows that annual mean wind power density during 2010-2017 at 100m above mean sea level was, respectively, 605.6, 542.0, 368.0, 282.0, 265.6, 87.6 and 321.5 Wm-2 at the seven sites, with average value of 353.2 Wm-2. Evidently, wind power potential demonstrates intra-annual variability, with greatest values occurring in December, while another peak value is observed in July. Wind speeds are lowest in May with another trough occurring in August. The data also display weak inter annual variability. The prevailing wind directions in the rim are mainly from opposing directions of N (winter and autumn) and S (summer). Response to Reviewers: The authors wish to thank reviewers for their constructive comments, which have greatly helped improve the quality of the present manuscript. We have carefully considered all remarks. Below, please find detailed responses to the comments. We would also like to extend our appreciation to the editors for their efforts.
Numerical solutions of the Korteweg-de Vries (KdV) and extended Korteweg-de Vries (eKdV) equation... more Numerical solutions of the Korteweg-de Vries (KdV) and extended Korteweg-de Vries (eKdV) equations are used to model the transformation of a sinusoidal internal tide as it propagates across the continental shelf. The ocean is idealized as being a two-layer fluid, justified by the fact that most of the oceanic internal wave signal is contained in the gravest mode. The model accounts for nonlinear and dispersive effects but neglects friction, rotation, and mean shear. The KdV model is run for a variety of idealized stratifications and unique realistic topographies to study the role of the nonlinear and dispersive effects. In all model solutions the internal tide steepens forming a sharp front from which a packet of nonlinear solitary-like waves evolves. Comparisons between KdV and eKdV solutions is explored. The model results for realistic topography and stratification are compared with observations made at moorings off Massachusetts in the Mid Atlantic Bight. Some features of the obs...
In this study, nearshore wind and wave climates and their potential as renewable energy sources a... more In this study, nearshore wind and wave climates and their potential as renewable energy sources are evaluated by means of buoy observational data for the Shenzhen coastal region. Six buoys were originally deployed in the region by the city local government of China in 2014, and are located in different areas of the study region, including Dapeng Bay, Daya Bay, Shenzhen Bay. The waters in these areas are relatively shallow, ranging in depth be-* Corresponding author.
Numerical solutions of the Kortewegde Vries (KdV) and extended Korteweg-de Vries (eKdV) equations... more Numerical solutions of the Kortewegde Vries (KdV) and extended Korteweg-de Vries (eKdV) equations are used to model the transformation of a sinusoidal internal tide as it propagates across the continental shelf. The ocean is idealized as being a two-layer fluid, justified by the fact that most of the oceanic internal wave signal is contained in the gravest mode. The model accounts for nonlinear and dispersive effects but neglects friction, rotation and mean shear. The KdV model is run for a number of idealized stratifications and unique realistic topographies to study the role of the nonlinear and dispersive effects. In all model solutions the internal tide steepens forming a sharp front from which a packet of nonlinear solitary-like waves evolve. Comparisons between KdV and eKdV solutions are made. The model results for realistic topography and stratification are compared with observations made at moorings off Massachusetts in the Middle Atlantic Bight. Some features of the observations compare well with the model. The leading face of the internal tide steepens to form a shock-like front, while nonlinear high-frequency waves evolve shortly after the appearance of the jump. Although not rank ordered, the wave of maximum amplitude is always close to the jump. Some features of the observations are not found in the model. Nonlinear waves can be very widely spaced and persist over a tidal period.
Environmental Science and Pollution Research, 2016
The environmental fate of polybrominated diphenyl ethers (PBDEs), a group of flame retardants tha... more The environmental fate of polybrominated diphenyl ethers (PBDEs), a group of flame retardants that are considered to be persistent organic pollutants (POPs), around the Zhuoshui River and Changhua County regions of Taiwan was assessed. An investigation into emissions, partitioning, and fate of selected PBDEs was conducted based on the equilibrium constant (EQC) fugacity model developed at Trent University, Canada. Emissions for congeners PBDE 47, PBDE 99, and PBDE 209 to air (4.9-92 × 10 −3 kg/h), soil (0.91-17.4 × 10 −3 kg/h), and water (0.21-4.04 × 10 −3 kg/h), were estimated by modifying previous models on PBDE emission rates by considering both industrial and domestic rates. It was found that fugacity modeling can give a reasonable estimation of the behavior, partitioning, and concentrations of PBDE congeners in and around Taiwan. Results indicate that PBDE congeners have a high affinity for partitioning into sediments then soils. As congener number decreases, the PBDEs then partition more readily into air. As the degree of bromination increases, congeners more readily partition to sediments. Sediments may then act as a long-term source of PBDEs which can be released back into the water column due to resuspension during storm events.
The air-sea exchange of two legacy persistent organic pollutants (POPs), γ-HCH and PCB 153, in th... more The air-sea exchange of two legacy persistent organic pollutants (POPs), γ-HCH and PCB 153, in the North Sea, is presented and discussed using results of regional fate and transport and shelf-sea hydrodynamic ocean models for the period 1996-2005. Air-sea exchange occurs through gas exchange (deposition and volatilization), wet deposition and dry deposition. Atmospheric concentrations are interpolated into the model domain from results of the EMEP MSC-East multi-compartmental model (Gusev et al, 2009). The North Sea is net depositional for γ-HCH, and is dominated by gas deposition with notable seasonal variability and a downward trend over the 10 year period. Volatilization rates of γ-HCH are generally a factor of 2-3 less than gas deposition in winter, spring and summer but greater in autumn when the North Sea is net volatilizational. A downward trend in fugacity ratios is found, since gas deposition is decreasing faster than volatilization. The North Sea is net volatilizational for PCB 153, with highest rates of volatilization to deposition found in the areas surrounding polluted British and continental river sources. Large quantities of PCB 153 entering through rivers lead to very high local rates of volatilization.
In this study, we investigated contributions of both local steric and remote baroclinic eects (i.... more In this study, we investigated contributions of both local steric and remote baroclinic eects (i.e., steric variations external to the region of interest) to the inter-annual variability of winter sea level in the North Sea, with respect to the North Atlantic Oscillation (NAO), for the period of 1953−2010. On inter-annual time scales in this period, the NAO is signicantly correlated to sea level variations in the North Sea only in the winter months (December−March), while its correlation to sea temperature over much of the North Sea is only signicant in January and February. The discrepancy in sea level between observations and barotropic tide and surge models forced by tides and local atmospheric forcing, i.e., local atmospheric pressure
European anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are southern, Lusitani... more European anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are southern, Lusitanian species needing warmer temperatures than boreal ones. After about 40 years of absence, they were observed again in increasing quantities in the North and Baltic Seas. Sardines re-invaded the North Sea around 1990, probably as a response to warmer temperatures associated with the strengthening of the North Atlantic Oscillation (NAO) in the late 1980s. However, surprisingly, increasing numbers of anchovy eggs, larvae, juveniles and adults were recorded only since the mid-1990s, indicating that the temperature rise in the winter months due to the NAO was not sufficient for triggering the reappearance and spawning of this species in more northern waters. Presumably, changes in current structures and increased summer temperatures since the mid-1990s, in association with the contraction of the subpolar gyre, were responsible for the expansion of the anchovy distributional range into the North Sea. Apparently, climate variability drives anchovies and sardines into North and Baltic Seas. We will discuss, which atmospheric (e.g., AMO, East Atlantic Pattern) and oceanographic (e.g. contraction of subpolar gyre) drivers might be responsible for the occurrence of anchovies and sardines in North and Baltic Seas and other changes observed in fish populations at the same time.
A regionally segmented multimedia fate model for the European continent is described together wit... more A regionally segmented multimedia fate model for the European continent is described together with an illustrative steady-state case study examining the fate of g-HCH (lindane) based on 1998 emission data. The study builds on the regionally segmented BETR North America model structure and describes the regional segmentation and parameterisation for Europe. The European continent is described by a 5 Â5 grid, leading to 50 regions together with four perimetric boxes representing regions buffering the European environment. Each zone comprises seven compartments including; upper and lower atmosphere, soil, vegetation, fresh water and sediment and coastal water. Inter-regions flows of air and water are described, exploiting information originating from GIS databases and other georeferenced data. The model is primarily designed to describe the fate of Persistent Organic Pollutants (POPs) within the European environment by examining chemical partitioning and degradation in each region, and inter-region transport either under steady-state conditions or fully dynamically. A test case scenario is presented which examines the fate of estimated spatially resolved atmospheric emissions of lindane throughout Europe within the lower atmosphere and surface soil compartments. In accordance with the predominant wind direction in Europe, the model predicts high concentrations close to the major sources as well as towards Central and Northeast regions. Elevated soil concentrations in Scandinavian soils provide further evidence of the potential of increased scavenging by forests and subsequent accumulation by organic-rich terrestrial surfaces. Initial model predictions have revealed a factor of 5-10 underestimation of lindane concentrations in the atmosphere. This is explained by an underestimation of source strength and/or an underestimation of European background levels. The model presented can further be used to predict deposition fluxes and chemical inventories, and it can also be adapted to provide characteristic travel distances and overall environmental persistence, which can be compared with other long-range transport prediction methods.
This study describes the ocean circulation o f the Indonesian Seas based on results using a 3D re... more This study describes the ocean circulation o f the Indonesian Seas based on results using a 3D regional model. The study is divided into 3 parts. In the first part, Chapter 2, the basic properties o f a developed regional model o f the circulation o f the Indonesian Seas are outlined. It is well known that the complex topography o f the region strongly influences temperature, salinity and current distributions there. One o f the significant properties o f this model is that all basic topographic features are resolved. The model has four open ports to simulate inflow o f North Pacific Water from the Mindanao Current, inflow o f South Pacific Water from the New Guinea Coastal Current, outflow to the Pacific Ocean due to the North Equatorial Counter Current, and outflow to the Indian Ocean due to the Indonesian Throughflow. Total transports through the open ports and port normal velocities are specified from observations. Orlanski's conditions are employed at the open ports with port normal velocity nudged to observed values and temperature and salinity to climatology. Port channels are introduced so the effects o f open boundary conditions do not impact the dynamics o f the main region. An additional friction was included in the vicinity o f some narrow passages and sills as a proxy for specific processes such as tides and internal waves that occur within these topographic features. Four experiments are discussed: seasonally varying and annual mean transports and port normal velocities
The fate and cycling of two selected legacy persistent organic pollutants (POPs), PCB 153 and γ-H... more The fate and cycling of two selected legacy persistent organic pollutants (POPs), PCB 153 and γ-HCH, in the North Sea in the 21st century have been modelled with combined hydrodynamic and fate and transport ocean models (HAMSOM and FANTOM, respectively). To investigate the impact of climate variability on POPs in the North Sea in the 21st century, future scenario model runs for three 10-year periods to the year 2100 using plausible levels of both in situ concentrations and atmospheric, river and open boundary inputs are performed. This slice mode under a moderate scenario (A1B) is sufficient to provide a basis for further analysis. For the HAMSOM and atmospheric forcing, results of the IPCC A1B (SRES) 21st century scenario are utilized, where surface forcing is provided by the REMO downscaling of the ECHAM5 global atmospheric model, and open boundary conditions are provided by the MPIOM global ocean model. <br><br> Dry gas deposition and volatilization of γ-HCH increase ...
Fate and transport ocean model Air-sea exchange Water column sediment exchange Seasonality and tr... more Fate and transport ocean model Air-sea exchange Water column sediment exchange Seasonality and trends The fate and cycling of two selected POPs is investigated for the North Sea system with an improved version of a fate and transport ocean model (FANTOM). The model uses atmospheric data from the EMEP MSC East POP model (Gusev et al., 2009), giving reasonable concentrations and seasonal distributions for the entire region, as opposed to the three observation stations that Ilyina et al. (2006) were limited to. Other model improvements include changes in the calculation of POP exchange between the water column and sediment. We chose to simulate the fate of two POPs with very different properties, γ-HCH and PCB 153. Since the fate and cycling of POPs are strongly affected by hydrodynamic processes, a high resolution version of the Hamburg Shelf Ocean Model (HAMSOM) was developed and utilised. Simulations were made for the period 1996-2005. Both models were validated by comparing results with available data, which showed that the simulations were of very satisfactory quality. Model results show that the North Sea is a net sink for γ-HCH and a net source to the atmosphere of PCB 153. Total masses of γ-HCH and PCB 153 in 2005 are reduced to 30% and 50%, respectively, of 1996 values. Storms resuspending bottom sediments into the water column mobilise POPs into the atmosphere and have the potential to deliver substantial loads of these POPs into Europe.
Background: Autoimmune diseases are more prevalent in women than in men, and such a disparity als... more Background: Autoimmune diseases are more prevalent in women than in men, and such a disparity also exists in animal models. In our studies with the mouse model of experimental autoimmune encephalomyelitis (EAE) induced with myelin proteolipid protein 139-151 (PLP) for multiple sclerosis, gender differences are well documented, in that only female, but not male, SJL mice show chronic relapsingremitting paralysis. Since EAE is typically mediated by CD4 T cells, we tested a hypothesis that the generation and expansion of antigen-specific CD4 T cells might be different between genders. Methods and findings: First, by creating a newer and more sensitive version of major histocompatibility complex class II tetramers called dextramers, we noted no differences in the generation of PLP-specific T cells in the peripheral repertoires of male and female SJL mice. Second, comparable numbers of PLP-specific T cells were found to be infiltrated into the brains of both genders as verified by flow cytometric analysis. Third, evaluation of molecules that positively or negatively regulate the expansion of effector T cells revealed that expression of cytotoxic T-lymphocyte associated protein 4 was tended to be more in the T cells that infiltrate into the brains of male than female mice. Finally, we analyzed the proteomic profiles in PLP 139-151specific T cells to identify additional novel molecules that may potentially contribute to the gender-disparity in the development of central nervous system autoimmunity. In conjunction with tandem mass spectrometric analysis and ingenuity pathway analysis, we have identified a panel of proteins found to be expressed gender dependently, suggesting that they can be regulated by sex steroids. Conclusions: Our data revealed expression of proteins that can potentially play a role in the development of diseases of multiple organs such as the central nervous system and cardiovascular system including cancers.
R-C. (2015). Assessing the environmental fate of selected polybrominated diphenyl ethers in the r... more R-C. (2015). Assessing the environmental fate of selected polybrominated diphenyl ethers in the region surrounding the Zhuoshui River of Taiwan based on an Equilibrium Constant fugacity model.
The Beibu Gulf Economic Rim of China is a key economic region in western China as demonstrated by... more The Beibu Gulf Economic Rim of China is a key economic region in western China as demonstrated by the "Beibu Gulf Cities Development Project" (2017) that plans to build a "Blue Livable Gulf" to balance environmental protection while providing sustainable economic development. This region has significant energy needs and is predicted to exhibit rapid growth in the future. By means of meteorological observations located at seven islands, a comprehensive statistical analysis on wind energy potential in the northern coastal part of the Beibu Gulf is conducted in this study. Specifically, wind speed, Weibull parameters, wind power density, as well as wind directions on various timescales are analyzed. The analysis shows that annual mean wind power density during 2010-2017 at 100m above mean sea level was, respectively, 605.6, 542.0, 368.0, 282.0, 265.6, 87.6 and 321.5 Wm-2 at the seven sites, with average value of 353.2 Wm-2. Evidently, wind power potential demonstrates intra-annual variability, with greatest values occurring in December, while another peak value is observed in July. Wind speeds are lowest in May with another trough occurring in August. The data also display weak inter annual variability. The prevailing wind directions in the rim are mainly from opposing directions of N (winter and autumn) and S (summer). Response to Reviewers: The authors wish to thank reviewers for their constructive comments, which have greatly helped improve the quality of the present manuscript. We have carefully considered all remarks. Below, please find detailed responses to the comments. We would also like to extend our appreciation to the editors for their efforts.
Numerical solutions of the Korteweg-de Vries (KdV) and extended Korteweg-de Vries (eKdV) equation... more Numerical solutions of the Korteweg-de Vries (KdV) and extended Korteweg-de Vries (eKdV) equations are used to model the transformation of a sinusoidal internal tide as it propagates across the continental shelf. The ocean is idealized as being a two-layer fluid, justified by the fact that most of the oceanic internal wave signal is contained in the gravest mode. The model accounts for nonlinear and dispersive effects but neglects friction, rotation, and mean shear. The KdV model is run for a variety of idealized stratifications and unique realistic topographies to study the role of the nonlinear and dispersive effects. In all model solutions the internal tide steepens forming a sharp front from which a packet of nonlinear solitary-like waves evolves. Comparisons between KdV and eKdV solutions is explored. The model results for realistic topography and stratification are compared with observations made at moorings off Massachusetts in the Mid Atlantic Bight. Some features of the obs...
In this study, nearshore wind and wave climates and their potential as renewable energy sources a... more In this study, nearshore wind and wave climates and their potential as renewable energy sources are evaluated by means of buoy observational data for the Shenzhen coastal region. Six buoys were originally deployed in the region by the city local government of China in 2014, and are located in different areas of the study region, including Dapeng Bay, Daya Bay, Shenzhen Bay. The waters in these areas are relatively shallow, ranging in depth be-* Corresponding author.
Numerical solutions of the Kortewegde Vries (KdV) and extended Korteweg-de Vries (eKdV) equations... more Numerical solutions of the Kortewegde Vries (KdV) and extended Korteweg-de Vries (eKdV) equations are used to model the transformation of a sinusoidal internal tide as it propagates across the continental shelf. The ocean is idealized as being a two-layer fluid, justified by the fact that most of the oceanic internal wave signal is contained in the gravest mode. The model accounts for nonlinear and dispersive effects but neglects friction, rotation and mean shear. The KdV model is run for a number of idealized stratifications and unique realistic topographies to study the role of the nonlinear and dispersive effects. In all model solutions the internal tide steepens forming a sharp front from which a packet of nonlinear solitary-like waves evolve. Comparisons between KdV and eKdV solutions are made. The model results for realistic topography and stratification are compared with observations made at moorings off Massachusetts in the Middle Atlantic Bight. Some features of the observations compare well with the model. The leading face of the internal tide steepens to form a shock-like front, while nonlinear high-frequency waves evolve shortly after the appearance of the jump. Although not rank ordered, the wave of maximum amplitude is always close to the jump. Some features of the observations are not found in the model. Nonlinear waves can be very widely spaced and persist over a tidal period.
Environmental Science and Pollution Research, 2016
The environmental fate of polybrominated diphenyl ethers (PBDEs), a group of flame retardants tha... more The environmental fate of polybrominated diphenyl ethers (PBDEs), a group of flame retardants that are considered to be persistent organic pollutants (POPs), around the Zhuoshui River and Changhua County regions of Taiwan was assessed. An investigation into emissions, partitioning, and fate of selected PBDEs was conducted based on the equilibrium constant (EQC) fugacity model developed at Trent University, Canada. Emissions for congeners PBDE 47, PBDE 99, and PBDE 209 to air (4.9-92 × 10 −3 kg/h), soil (0.91-17.4 × 10 −3 kg/h), and water (0.21-4.04 × 10 −3 kg/h), were estimated by modifying previous models on PBDE emission rates by considering both industrial and domestic rates. It was found that fugacity modeling can give a reasonable estimation of the behavior, partitioning, and concentrations of PBDE congeners in and around Taiwan. Results indicate that PBDE congeners have a high affinity for partitioning into sediments then soils. As congener number decreases, the PBDEs then partition more readily into air. As the degree of bromination increases, congeners more readily partition to sediments. Sediments may then act as a long-term source of PBDEs which can be released back into the water column due to resuspension during storm events.
The air-sea exchange of two legacy persistent organic pollutants (POPs), γ-HCH and PCB 153, in th... more The air-sea exchange of two legacy persistent organic pollutants (POPs), γ-HCH and PCB 153, in the North Sea, is presented and discussed using results of regional fate and transport and shelf-sea hydrodynamic ocean models for the period 1996-2005. Air-sea exchange occurs through gas exchange (deposition and volatilization), wet deposition and dry deposition. Atmospheric concentrations are interpolated into the model domain from results of the EMEP MSC-East multi-compartmental model (Gusev et al, 2009). The North Sea is net depositional for γ-HCH, and is dominated by gas deposition with notable seasonal variability and a downward trend over the 10 year period. Volatilization rates of γ-HCH are generally a factor of 2-3 less than gas deposition in winter, spring and summer but greater in autumn when the North Sea is net volatilizational. A downward trend in fugacity ratios is found, since gas deposition is decreasing faster than volatilization. The North Sea is net volatilizational for PCB 153, with highest rates of volatilization to deposition found in the areas surrounding polluted British and continental river sources. Large quantities of PCB 153 entering through rivers lead to very high local rates of volatilization.
In this study, we investigated contributions of both local steric and remote baroclinic eects (i.... more In this study, we investigated contributions of both local steric and remote baroclinic eects (i.e., steric variations external to the region of interest) to the inter-annual variability of winter sea level in the North Sea, with respect to the North Atlantic Oscillation (NAO), for the period of 1953−2010. On inter-annual time scales in this period, the NAO is signicantly correlated to sea level variations in the North Sea only in the winter months (December−March), while its correlation to sea temperature over much of the North Sea is only signicant in January and February. The discrepancy in sea level between observations and barotropic tide and surge models forced by tides and local atmospheric forcing, i.e., local atmospheric pressure
European anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are southern, Lusitani... more European anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are southern, Lusitanian species needing warmer temperatures than boreal ones. After about 40 years of absence, they were observed again in increasing quantities in the North and Baltic Seas. Sardines re-invaded the North Sea around 1990, probably as a response to warmer temperatures associated with the strengthening of the North Atlantic Oscillation (NAO) in the late 1980s. However, surprisingly, increasing numbers of anchovy eggs, larvae, juveniles and adults were recorded only since the mid-1990s, indicating that the temperature rise in the winter months due to the NAO was not sufficient for triggering the reappearance and spawning of this species in more northern waters. Presumably, changes in current structures and increased summer temperatures since the mid-1990s, in association with the contraction of the subpolar gyre, were responsible for the expansion of the anchovy distributional range into the North Sea. Apparently, climate variability drives anchovies and sardines into North and Baltic Seas. We will discuss, which atmospheric (e.g., AMO, East Atlantic Pattern) and oceanographic (e.g. contraction of subpolar gyre) drivers might be responsible for the occurrence of anchovies and sardines in North and Baltic Seas and other changes observed in fish populations at the same time.
A regionally segmented multimedia fate model for the European continent is described together wit... more A regionally segmented multimedia fate model for the European continent is described together with an illustrative steady-state case study examining the fate of g-HCH (lindane) based on 1998 emission data. The study builds on the regionally segmented BETR North America model structure and describes the regional segmentation and parameterisation for Europe. The European continent is described by a 5 Â5 grid, leading to 50 regions together with four perimetric boxes representing regions buffering the European environment. Each zone comprises seven compartments including; upper and lower atmosphere, soil, vegetation, fresh water and sediment and coastal water. Inter-regions flows of air and water are described, exploiting information originating from GIS databases and other georeferenced data. The model is primarily designed to describe the fate of Persistent Organic Pollutants (POPs) within the European environment by examining chemical partitioning and degradation in each region, and inter-region transport either under steady-state conditions or fully dynamically. A test case scenario is presented which examines the fate of estimated spatially resolved atmospheric emissions of lindane throughout Europe within the lower atmosphere and surface soil compartments. In accordance with the predominant wind direction in Europe, the model predicts high concentrations close to the major sources as well as towards Central and Northeast regions. Elevated soil concentrations in Scandinavian soils provide further evidence of the potential of increased scavenging by forests and subsequent accumulation by organic-rich terrestrial surfaces. Initial model predictions have revealed a factor of 5-10 underestimation of lindane concentrations in the atmosphere. This is explained by an underestimation of source strength and/or an underestimation of European background levels. The model presented can further be used to predict deposition fluxes and chemical inventories, and it can also be adapted to provide characteristic travel distances and overall environmental persistence, which can be compared with other long-range transport prediction methods.
This study describes the ocean circulation o f the Indonesian Seas based on results using a 3D re... more This study describes the ocean circulation o f the Indonesian Seas based on results using a 3D regional model. The study is divided into 3 parts. In the first part, Chapter 2, the basic properties o f a developed regional model o f the circulation o f the Indonesian Seas are outlined. It is well known that the complex topography o f the region strongly influences temperature, salinity and current distributions there. One o f the significant properties o f this model is that all basic topographic features are resolved. The model has four open ports to simulate inflow o f North Pacific Water from the Mindanao Current, inflow o f South Pacific Water from the New Guinea Coastal Current, outflow to the Pacific Ocean due to the North Equatorial Counter Current, and outflow to the Indian Ocean due to the Indonesian Throughflow. Total transports through the open ports and port normal velocities are specified from observations. Orlanski's conditions are employed at the open ports with port normal velocity nudged to observed values and temperature and salinity to climatology. Port channels are introduced so the effects o f open boundary conditions do not impact the dynamics o f the main region. An additional friction was included in the vicinity o f some narrow passages and sills as a proxy for specific processes such as tides and internal waves that occur within these topographic features. Four experiments are discussed: seasonally varying and annual mean transports and port normal velocities
The fate and cycling of two selected legacy persistent organic pollutants (POPs), PCB 153 and γ-H... more The fate and cycling of two selected legacy persistent organic pollutants (POPs), PCB 153 and γ-HCH, in the North Sea in the 21st century have been modelled with combined hydrodynamic and fate and transport ocean models (HAMSOM and FANTOM, respectively). To investigate the impact of climate variability on POPs in the North Sea in the 21st century, future scenario model runs for three 10-year periods to the year 2100 using plausible levels of both in situ concentrations and atmospheric, river and open boundary inputs are performed. This slice mode under a moderate scenario (A1B) is sufficient to provide a basis for further analysis. For the HAMSOM and atmospheric forcing, results of the IPCC A1B (SRES) 21st century scenario are utilized, where surface forcing is provided by the REMO downscaling of the ECHAM5 global atmospheric model, and open boundary conditions are provided by the MPIOM global ocean model. <br><br> Dry gas deposition and volatilization of γ-HCH increase ...
Fate and transport ocean model Air-sea exchange Water column sediment exchange Seasonality and tr... more Fate and transport ocean model Air-sea exchange Water column sediment exchange Seasonality and trends The fate and cycling of two selected POPs is investigated for the North Sea system with an improved version of a fate and transport ocean model (FANTOM). The model uses atmospheric data from the EMEP MSC East POP model (Gusev et al., 2009), giving reasonable concentrations and seasonal distributions for the entire region, as opposed to the three observation stations that Ilyina et al. (2006) were limited to. Other model improvements include changes in the calculation of POP exchange between the water column and sediment. We chose to simulate the fate of two POPs with very different properties, γ-HCH and PCB 153. Since the fate and cycling of POPs are strongly affected by hydrodynamic processes, a high resolution version of the Hamburg Shelf Ocean Model (HAMSOM) was developed and utilised. Simulations were made for the period 1996-2005. Both models were validated by comparing results with available data, which showed that the simulations were of very satisfactory quality. Model results show that the North Sea is a net sink for γ-HCH and a net source to the atmosphere of PCB 153. Total masses of γ-HCH and PCB 153 in 2005 are reduced to 30% and 50%, respectively, of 1996 values. Storms resuspending bottom sediments into the water column mobilise POPs into the atmosphere and have the potential to deliver substantial loads of these POPs into Europe.
Uploads
Papers by Kieran O'Driscoll