Mass Circulation Research Articles

Periodic Coronal Rain Driven by Self-consistent Heating Process in a Radiative Magnetohydrodynamic Simulation

The periodic coronal rain and in-phase radiative intensity pulsations have been observed in multiple wavelengths in recent years. However, due to the lack of three-dimensional coronal magnetic fields and thermodynamic data in observations, it remains challenging to quantify the coronal heating rate that drives the mass cycles. In this work, based on the MURaM code, we conduct a three-dimensional radiative magnetohydrodynamic simulation spanning from the convective zone to the corona, where the solar atmosphere is heated self-consistently through dissipation resulting from magnetoconvection. For the first time, we model the periodic coronal rain in an active region. With a high spatial resolution, the simulation well resembles the observational features across different extreme-ultraviolet wavelengths. These include the realistic interweaving coronal loops, periodic coronal rain, and periodic intensity pulsations, with two periods of 3.0 hr and 3.7 hr identified within one loop system. Moreover, the simulation allows for a detailed three-dimensional depiction of coronal rain on small scales, revealing adjacent shower-like rain clumps ∼500 km in width and showcasing their multithermal internal structures. We further reveal that these periodic variations essentially reflect the cyclic energy evolution of the coronal loop under thermal nonequilibrium state. Importantly, as the driver of the mass circulation, the self-consistent coronal heating rate is considerably complex in time and space, with hour-level variations in 1 order of magnitude, minute-level bursts, and varying asymmetry reaching ten times between footpoints. This provides an instructive template for the ad hoc heating function and further enhances our understanding of the coronal heating process.

Spatiotemporal variations in vertical profiles of Fukushima-derived 137Cs in the Kuroshio-Oyashio confluence region from 2011 to 2018: Implications for local water mass dynamics and basin-scale circulations

Tracking the processes of the spread of Fukushima-derived 137Cs (137CsF) contributes to a better understanding of North Pacific water dynamics. In this study, the vertical distributions of 137Cs and 90Sr in the Kuroshio-Oyashio confluence region were investigated in May 2018, and 137CsF was separated from the background 137Cs by exploiting the constant global fallout 137Cs/90Sr ratio. To the north of 35°N, 137CsF peaked in the upper 100 m layer, whereas in and just south of the Kuroshio Extension (KE), 137CsF exhibited subsurface peaks at depths of 300–500 m. The T/S diagram indicated that the 137CsF maxima were distributed mainly within the range of lighter central mode water (L-CMW) during May 2018, even in and just south of the KE. We found that anticyclonic (cyclonic) eddies can promote (prevent) the intrusion of 137CsF into the ocean interior. In addition, the high activity of regional anticyclonic eddies in the upstream KE resulted in the modification of 137CsF-rich subtropical mode water (STMW) to L-CMW. Temporal changes in the 137CsF vertical profiles and inventories revealed that 137CsF in transitional and subarctic regions has increased since July 2014, implying the existence of additional sources of 137CsF after July 2014, whereas 137CsF in and just south of the KE has remained constant since July 2014, indicating that the 137CsF entrained by STMW has recirculated in the western subtropical gyre. The comparison between surface 137CsF concentrations in transitional and subarctic regions and those observed in Oyashio waters during 2018 did not support the return of 137CsF to our study area via the western or whole subarctic gyre by May 2018. In contrast, the sea surface height distributions from 2016 to 2017 provide clear evidence that the warm-core rings and quasistationary Isoguchi western jet generated from the Kuroshio Current and KE intruded into the transitional region and even into the subarctic region. Therefore, we concluded that a portion of the 137CsF that subducted into the subtropical western North Pacific during 2011–2012 have entered the transition zone and even the subarctic region since 2016. These results not only enhance our understanding of the protracted spread and fate of 137CsF in the North Pacific but also provide important insights into North Pacific water mass circulation and mixing patterns.

Prediction of the finished tablet coating variability in pan coaters by coupling CFD-DEM and Monte Carlo simulations: Method development and validation

We present a numerical approach to predict the long-term coating variability of tablets in pan coaters by combining coupled computational fluid dynamics-discrete element method (CFD-DEM) simulations with a Monte-Carlo method. In CFD-DEM simulations, the coater geometry, operating conditions, air flow and exact tablet shapes are directly simulated to obtain statistical distributions of tablet coating mass gain and circulation time through the spray zone. These short-term distributions (∼102 s) serve as input to a Monte Carlo (MC) method to efficiently predict the coefficient of variation in pan coaters for timescales relevant to commercial manufacture (∼104 s). These predictions achieved reasonable agreement with experimental coating thickness measurements via both the manual gauge and optical coherence tomography (OCT) from coating trials on L.B. Bohle film coaters at different scales. This method enables the application of digital tools as efficient alternatives to resource-intensive experimental trials in determining the appropriate coating process parameters.

Modelling and optimization of operating parameters for improved steam energy production in the food and beverage industry in a developing country

Efficient steam energy production was essential for reducing energy consumption and operational costs while enhancing productivity, particularly in industrial settings prone to explosions due to boiler parameter control issues. This challenge was especially acute in the food and beverage industry amid rising energy costs and stricter environmental regulations, highlighting the importance of optimizing steam energy production. This study focused on refining operational parameters in a steam production plant to maximize steam energy output. It utilized mathematical models and optimization tools to identify ideal operational conditions and investigate extreme scenarios. Design-Expert version 13.0 statistical software and Response Surface Methodology (RSM) via Centre Composite Design (CCD) were employed to create a comprehensive design matrix encompassing key variables like time, pressure levels, temperature, mass flow rate, and steam energy production across three experimental levels. The research revealed that increased pressure and time significantly boosted steam energy production by leveraging water’s energy content rise under initial conditions, thus improving efficiency by reducing required water mass circulation. Moreover, elevated temperature and extended operation enhanced economizer efficiency, leading to increased heat recovery and reduced steam generation. Steam generation also increased with temperature and time due to the pressure rise during boiling, necessitating more energy for steam conversion. An optimum yield of steam energy of 620 Cal was attained at a time, pressure, temperature, and mass flow rate of 1 h, 16.97 MPa, 249.5°C, and 59.85 kg/s, respectively. The mathematical model developed is accurate, reliable, responsive, and can replicate the experimental data due to the high F-value (24.48), low CV (0.94) low p-value (< 0.005), and high R2 (0.9821) value close to 1. This research promises to enhance the efficiency of steam energy production in the food and beverage industry by reducing the need for resource-intensive experimental procedures, thus lowering costs and resource consumption.

Spatial and Temporal Variability of Turbulent Mixing in the Deep Northwestern Pacific

AbstractSmall‐scale turbulent mixing supplies potential energy for the upwelling of deep waters in the abyssal ocean, a key component of the global overturning circulation. This process is particularly significant in critical regions such as the Northwestern Pacific where the upwelling structure of deep waters remains poorly understood due to limited knowledge of deep ocean mixing. Here, we investigate the full‐depth spatiotemporal variability of turbulent mixing in the deep Northwestern Pacific based on hydrographic data collected over repeated surveys. Nineteen‐year‐average diapycnal diffusivity of 1.42 × 10−4 m2 s−1 is reveled in the deep Philippine Sea, indicating significantly stronger mixing compared to the stratified ocean interior. Spatially, turbulent mixing strengthens toward the bottom and intensifies westward from the open Pacific to the Philippine Sea due to rough topography. At certain mixing hotspots, enhanced mixing can penetrate up to 2,500 m above the bottom, suggesting a substantial potential for upwelling. Below 2,000 m, turbulent mixing exhibits pronounced seasonal variation that deep mixing is more intense in summer (winter) than in winter (summer) in the West Caroline Basin (the Parece Vela Basin). This spatially varying seasonality may be attributed to the inhomogeneous internal tidal energy dissipation in the Northwestern Pacific. Our study will serve to clarify the modulation of turbulent mixing to deep‐water mass transformation and circulation in the Northwestern Pacific.

Influence of changing water mass circulation on detrital component and carbon burial of late Pleistocene and Holocene sediments in the eastern-central Mid-Adriatic deep

A sediment core was retrieved in the eastern-central Mid-Adriatic Deep (MAD) to study the changes in the water mass circulation and their effect on carbon burial efficiency and the provenance of a detrital sediment component. An age-depth model of the sediment core POS-514-40-11 is based on radiocarbon dating and tephrochronology. Two tephra were correlated to the Neapolitan Yellow Tuff and Pomici di Mercato eruptions, extending the previously known distribution of Pomici di Mercato tephra. Based on the analysis of heavy mineral (HM) assemblages throughout the core, for the first time the occurrence of Eastern Adriatic current (EAC) was estimated at ca. 15 ka BP, i.e., at the beginning of the post last glacial maximum (LGM) transgression. During the late Pleistocene, the detrital component was dominated by Paleo-Po river sediments, which gradually shifted toward the Albanian province as a basin-wide counterclockwise circulation was established. Mass accumulation rates of organic carbon (OC), stable isotopes of carbon (δ 13C) and nitrogen (δ 15N) as well as C/N ratios, showed that carbon burial was affected by sea level rise and climatic changes. Climatic effects are observed during cold periods i.e., the Younger Dryas and the 8.4–7.9 ka cold period when terrestrial OC was dominant. In the latter case dominance of terrestrial carbon was due to the North Adriatic dense water (NAddW) influence. On the other hand, sea level rise increased MAD distance from the main river mouths/deltas, resulting in decreased influx of terrestrial organic carbon and lower accumulation rates of organic carbon in general. This reconstruction of the oceanographic setting is valuable considering that the Adriatic Sea is one of the key locations for the formation of DW and thus affects the overall Mediterranean circulation.

Continental cold-air-outbreaks under the varying stratosphere-troposphere coupling regimes during stratospheric Northern Annular Mode events

A Stratospheric Northern Annular Mode (SNAM) phase-based composite analysis reveals that continental Cold Air Outbreaks (CAOs) can occur during both positive and negative SNAM events. CAOs tend to occur over Asia, characterized by a meridional-dipole surface temperature anomaly pattern (cold midlatitudes and warm high-latitudes) when the SNAM index is decreasing or the stratospheric polar vortex is weakening, but over North America and Europe with a meridionally-homogeneous pattern when the SNAM index is increasing or the stratospheric polar vortex is strengthening. While the decreasing SNAM is dominated by a stronger stratospheric poleward warm branch (WB-ST) of the isentropic meridional mass circulation and vice versa, the CAOs always follow a stronger tropospheric poleward warm branch (WB-TR) and an equatorward cold branch (CB) of the isentropic meridional mass circulation. The correspondence between the stronger/weaker WB-ST and stronger/weaker WB-TR&CB during majority of SNAM phases (referred to as stratosphere-troposphere coupling regimes) is responsible for the CAOs in Asia. During the remaining phases (stratosphere-troposphere decoupling regimes), in accompany with a weaker/stronger WB-ST, the WB-TR&CB are stronger/weaker and relates to the CAOs occurred in North America and Europe. The coupling regimes when the stratospheric polar vortex is weakening/strengthening are mainly attributed to the E-P flux convergence/divergence from the middle troposphere to the lower stratosphere, the larger wave amplitude throughout the column, and anomalous tropospheric wave flux mainly in the Asia in subpolar latitudes. The decoupling regimes, however, are mainly related to the anomalous westward-tilting of waves and the wave flux reflection toward the North America or Europe.

Research on the generalization issue of the heterogeneous QC-EMMS drag model for gas-solid fluidization

In the circulating fluidized bed (CFB), the non-uniform mesoscale structure formed by the particle clustering effect causes a substantial decrease in the gas-solid drag. Since the degree of particle clustering varies with operating conditions, an accurate drag model needs to be universal in different heterogeneous flow conditions. In this study, the relationships between the Ψ factor in clusters' solid holdup model that characterizes the flow non-uniformity and the operating parameters of CFB (including slip velocity Reynolds number, Re*, bed-averaged solid volume fraction, εs,bed, and solid mass circulation rate, Gs) are established. It improves the adaptability of the QC-EMMS drag model under different working conditions. In previous research, we established two types of models that related Ψ factor to Re* and εs,bed respectively. However, there exists a problem of high dispersion of points, indicating that the selected parameters cannot fully describe the flow non-uniformity. Therefore, Gs is reintroduced to modify the two types of models. The results show that the prediction accuracy of the modified models is improved and the relative error is <10%, indicating that the non-uniform factor Ψ has a strong correlation with Gs. In addition, the quantitative relation between Re*, εs,bed, and Gs is derived from modified models, and the trend of relation is highly consistent with the fluidization diagram proposed by Yerushalmi J., which verifies the accuracy of modified models. Finally, numerical simulation of typical CFB cases proves the adaptability of the modified models in wide operating conditions of fluidization.

Composite cores of monopoles and Alice rings in spin-2 Bose-Einstein condensates

We show that energy relaxation causes a point defect in the uniaxial-nematic phase of a spin-2 Bose-Einstein condensate to deform into a spin-Alice ring that exhibits a composite core structure with distinct topology at short and long distances from the singular line. An outer biaxial-nematic core exhibits a spin half-quantum vortex structure with a uniaxial-nematic inner core. By numerical simulation, we demonstrate a dynamical oscillation between the spin-Alice ring and a split-core hedgehog configuration via the appearance of ferromagnetic rings with associated vorticity inside an extended core region. We further show that a similar dynamics is exhibited by a spin-Alice ring surrounding a spin-vortex line resulting from the relaxation of a monopole situated on a spin-vortex line in the biaxial-nematic phase. In the cyclic phase, similar states are shown instead to form extended phase-mixing cores containing rings with fractional mass circulation or cores whose spatial shape reflects the order-parameter symmetry of a cyclic inner core, depending on the initial configuration. Published by the American Physical Society 2024

The seasonal evolution of the Yellow Sea Cold Water Mass Circulation: Roles of fronts, thermoclines, and tidal rectification

The Yellow Sea Cold Water Mass (YSCWM), surrounded by thermocline and fronts, is one of the most notable hydrological characteristics of the Yellow Sea (YS) in the summer. Temperature structure at the boundary of the YSCWM drives the Yellow Sea Cold Water Mass Circulation (YSCWMC). However, the 3D structure of YSCWMC remains unclear. The position, seasonal evolution, and dynamical mechanisms of the YSCWMC were examined by observations and high-resolution numerical model. It was found that the core of the YSCWMC is located at the junction of the fronts and the thermocline during the summer. Furthermore, the YSCWMC exhibits remarkable seasonal variations characterized by a progressive shrinking and deepening dependence on the position and strength of the fronts and thermocline. The YSCWMC is geostrophic at the basin scale, with the barotropic pressure term determining the direction of the circulation and the baroclinic pressure term controlling the vertical structure of the circulation. Fronts yield a baroclinic effect in the thermal field and affect the sea surface elevation in the barotropic process. Therefore, fronts are crucial to the formation of the YSCWMC. Nevertheless, under conditions of steep topography, tidal rectification is comparable to the frontal contribution to the circulation.

Anomalous Emission from Li- and Na-like Ions in the Corona Heated via Alfvén Waves

The solar ultraviolet intensities of spectral lines originating from Li- and Na-like ions have been observed to surpass the expectations derived from plasmas with coronal approximation. The violation of the coronal approximation can be partially attributed to nonequilibrium ionization (NEI) due to dynamic processes occurring in the vicinity of the transition region. To investigate the impact of these dynamics in the Alfvén wave-heated coronal loop, a set of equations governing NEI for multiple ion species was solved numerically in conjunction with 1.5-dimensional magnetohydrodynamic equations. Following the injection of Alfvén waves from the photosphere, the system undergoes a time evolution characterized by phases of evaporation, condensation, and quasi-steady states. During the evaporation phase, the ionization fractions of Li- and Na-like ions were observed to increase when compared to the fractions in ionization equilibrium, which led to an enhancement in the intensity of up to 1.6. This over-fractionation of Li- and Na-like ions was found to be induced by the evaporation process. While collisions between shocks and the transition region temporarily led to deviations from ionization equilibrium, on average over time, these deviations were negligible. Conversely, under-fractions of the ionization fraction led to a reduction in intensity down to 0.9 during the condensation phase and the quasi-steady state. Given the dependency of the over/under-fractionation on mass circulations between the chromosphere and the corona, these observations will serve as valuable benchmarks to validate not only Alfvén wave models but also other existing mechanisms on coronal heating.

Topological interfaces crossed by defects and textures of continuous and discrete point group symmetries in spin-2 Bose-Einstein condensates

We systematically and analytically construct a set of spinor wave functions representing defects and textures that continuously penetrate interfaces between coexisting, topologically distinct magnetic phases in a spin-2 Bose-Einstein condensate. These include singular and nonsingular vortices carrying mass or spin circulation that connect across interfaces between biaxial- and uniaxial nematic, cyclic and ferromagnetic phases, as well as vortices terminating as monopoles on the interface (“boojums”). The biaxial-nematic and cyclic phases exhibit discrete polytope symmetries featuring non-Abelian vortices and we investigate a pair of noncommuting line defects within the context of a topological interface. By numerical simulations, we characterize the emergence of nontrivial defect core structures, including the formation of composite defects. Our results demonstrate the potential of spin-2 Bose-Einstein condensates as experimentally accessible platforms for exploring interface physics, offering a wealth of combinations of continuous and discrete symmetries. Published by the American Physical Society 2024

Illustrating the future

In the early 1900s, Sweden looked to its north, to “Lappland” as its “land of the future” – an optimistic, utopian vision that tied Sweden’s emergence as a nation-state both to the north’s untapped resources as well as to its open, pristine landscape as a place of symbolic regenerative potentiality – a Nature in which Swedes could re-create themselves. At the same time, the Swedish publishing industry was emerging as a social force, and with it the proliferation of mass-produced images. Photographs, illustrations, engravings, and facsimiles, circulating with scant reference to an original, were powerful political and commercial agents in creating competing mythologies of space and place – one a “found”, natural paradise, one an invented utopia, ripe for development. This article examines the discursive formation of Lapland as it was transformed into such a landscape of desire through the mass production and circulation of visual images – in particular photographs – that were continuously recontextualized, recirculated, remediated, and consumed.

Water masses stratification and circulation in the southern part of Banggai Upwelling Region in Maluku Sea

Banggai Waters is in the western Maluku Sea, where the secondary pathway of Indonesian Throughflow passes and seasonal coastal upwelling takes place in this region, providing a high marine productivity and potential fishing ground. This study aims to describe water mass stratification and circulation using CTD casts and SADCP section datasets from the BUDEE cruise in September 2022 onboard RV Baruna Jaya VIII. The results show that mixed layer depth varies between 43-112 m with a mean temperature of 25.82(± 0.88) ºC. North Pacific water origin (NPSW and NPIW) is present in this southern section. The depth of chlorophyll maximum is much shallower in the upwelling center. Furthermore, for the first time, we identified a strong northward flow from the Bote Strait, disrupting Banggai upwelling water with cooler and fresher Banda water. Estimates of northward transport volume through this strait is about 0.531 Sv.

O protagonismo docente no espaço-tempo da transição democrática das décadas de 1970-80, no Brasil e em Portugal

The article revisits and updates questions that guided research that analyzed the repertoires of action adopted by teachers in the face of democratic construction processes that reached their peak in the 1970s, in Brazil and Portugal (Xavier,2013). Its central objective is to analyze the identity negotiations (Dubar, 2005) that permeated the political protagonism exercised by teachers in the actions and associations created in the influx of these movements. In the first topic, it locates the teaching movements in the space and time of the democratic transition and presents the questions that guided the writing of this article. In the second topic, it analyzes printed sources such as the mass circulation newspapers in Rio de Janeiro and the “O Professor” Magazine, with a view to observing the dissonant views regarding the establishment of an image of the teachers who participated in these movements. The third topic takes a statement relating to the experience of self-management lived in aPortuguese secondary school and highlights its reverberations in the interviewee's professional self-perception. In the final considerations, a brief reflection is developed on the disputes over the control of teaching identities and also on possible developments of this study. As a result of the analysis developed, it was possible to perceive the constitution of an engaged and autonomous teaching identity, through the analysis of the Magazine "O Professor". In turn, the mass circulation newspapers in Rio de Janeiro expressed the perspective of establishing a deviant identity in the face of teaching's political protagonism, triggering society's moral panic (Adorno, 1998), by condemning the collective actions that were part of the political repertoire of this professional group

Functioning of borrowed words in the mental lexicon of Ukrainians

The article analyzes the associative meaning of the stimulus word "donat" in the mental lexicon of native speakers of the Ukrainian language, raises the problem of the specificity of learning borrowed words in the Ukrainian language. The role of the media in the introduction of a new lexical unit into mass circulation and aspects of the actualization of the use of the word due to the influence of social and political events are considered. The question of the functioning of new lexical units and their place in the mental lexicon is highlighted. Shades of associative meanings of the stimulus words "donate" and "help" were studied. The obtained results confirm that the associative experiment can provide not only linguistic, but also psychological and social information.

A Survey of Magnetic Field Line Curvature in Jovian Dawn Magnetodisc

AbstractThe Jovian magnetosphere is highly dynamic, influenced by both solar wind and internal processes associated with the rapid planetary rotation and Io's volcanic activities. Accompanying the mass and energy circulations driven by the magnetospheric dynamics, the magnetic configuration also changes dramatically. One of the crucial parameters to characterize the magnetic configuration is magnetic field line curvature (FLC), which generally describes how stretched the field line is. The curvature is pivotal to influence particle behaviors, for example, pitch angle scattering which may lead to auroral particle precipitation. In this work, a method is proposed to investigate the real‐time magnetic FLC in Jovian current sheet using the magnetic field data from the Juno spacecraft. The results indicate that the FLC scattering of ions and relativistic electrons are common in Jovian magnetosphere, providing a crucial insight to understand the particle behaviors.

Evaluation of Changes in the Scale and Direction of Thermal Pollution Flows in the Kalinin NPP Cooling Lakes From 1985 to 2020

The article evaluates the change in the scale and direction of thermal pollution flows of the cooling lakes of the Kalinin NPP from 1985 to 2020 based on the use of Earth remote sensing data. A retrospective analysis was carried out using satellite images obtained by the sensors of the Landsat series satellites. An analysis of the distribution of surface water temperature over the water area of NPP cooling lakes has been carried out. The change in the structure of thermal pollution after the increase in the capacity of the Kalinin NPP is determined. The temperature of the cooling lakes of the Kalinin NPP was estimated relative to the background indicators in the lakes-analogues, which were used as nearby Lake Navolok and Lake Kezadra. The study identified five stages of transformation of the water mass circulation system in the cooling lakes of the Kalinin NPP.

Late Cenomanian Plenus event in the Western Interior Seaway

The Late Cenomanian Plenus Cold Event is one of the most enigmatic paleoclimate episodes in Earth history with potential to inform understanding of global climate system variability under greenhouse warming conditions, as well as internal feedback pathways that modulate such variability. Following an interpreted massive addition of volcanic CO2 to the atmosphere and warming that led to a major ocean anoxic event (OAE2), there was a brief interval of cooling recorded in oxygen isotopes and biogeographic data. Here we present evidence that cooling was absent or muted within the Western Interior Seaway (WIS). Clumped isotope data from the basin suggest persistent extreme warmth during the Late Cenomanian, macroinvertebrate fossil assemblages do not record a decrease in temperature, and changes in other paleoceanographic proxies do not correlate temporally with Plenus interval signals from other locales. Using select proxy data to guide construction of GCM model simulations, we explore possible hypotheses to explain these observations. Our results suggest that the paleogeographic configuration of the basin and its gateways to adjoining oceans, which evolved in association with changing pCO2 and sea level, influenced winter sea ice formation at the northern aperture of the seaway, water mass circulation, salinity, temperature, and water column stratification. We propose that northward advection of warm Tethyan water muted expression of Plenus cooling in the seaway. Understanding the unique character of the Western Interior paleoceanographic record provides critical input for the development of robust models of ancient Earth System dynamics and should aid predictions of future climate system dynamics.

Toxic phytoplankton in eutrophic regional seas: an overview

&lt;p&gt;Toxic algal blooms have become a major environmental problem over the last few decades because of their impact on fisheries, leisure activities, national income and human health. It is known that Harmful Algal Blooms (HABs) can occur naturally but the frequency of occurrence as well as their geographical distribution are alarming. HABs, beyond the scientific interest, have been an issue of concern for policy makers due to the high cost for implementing management practices. Unlike other marine environmental problems, the causes of HAB formation are not known so far with certainty and a high degree of uncertainty remains, regarding possible triggering mechanisms. Various factors, apart from nutrient concentrations, seem to be connected with this phenomenon: abundance, presence and absence of phytoplankton species, presence of grazers, weather conditions, seawater temperature and water mass circulation patterns, have already been reported in the scientific literature as potential factors. However, there are strong indications that eutrophic conditions play a paramount role in HABs formation. Machine learning methods, applied over the last few years to predict HAB’s occurrences, have also confirmed the role of nutrients. In the present work, toxic algal blooms in regional seas characterized by eutrophic conditions that is the Mediterranean Sea, the Black Sea, the Baltic Sea, the North Sea, Wider Caribbean Region and the South China Sea are reviewed. Relevant issues including the drivers of eutrophication triggering HAB’s events as well as effects on ecosystem services and socio-economic consequences are also considered.&lt;/p&gt;&#x0D;