Search Results (59)

At present, sea ice remains a critical factor affecting the safety of vessel operations along the Northern Sea Route (NSR). However, inconsistencies between the navigability outcomes derived from the criteria for the admission of ships in the area of the Northern Sea Route (NSR criteria) and the polar operational limit assessment risk indexing system (POLARIS) methodology present challenges for navigational decision-making. This study aims to conduct a systematic comparison of the POLARIS methodology and the NSR criteria in evaluating the navigability of independently operating vessels classified as Arc4 to Arc9. Through comparative calculations of navigability and the navigability rates for six ice-class vessels across 27 districts using the two methods, this study reveals the consistencies and discrepancies in their navigability outcomes. Firstly, using the POLARIS methodology, the risk index outcome (RIO) is calculated for six ice-class vessels across 27 districts. For these districts, the navigability threshold is defined when 95% or more of the area exhibits an RIO greater than or equal to zero. Secondly, using the NSR criteria, navigability ratios for six ice-class vessels under varying ice conditions are evaluated. A navigability threshold is defined when 95% or more of the ice conditions in a district are classified as navigable. Finally, a quantitative comparison of the weekly navigability ratios obtained by the two methods is conducted to reveal the consistencies and discrepancies in the navigability outcomes of each ice-class vessel across different NSR districts. The results indicate that the consistency between the navigability outcomes of the two methods decreases with lower vessel ice classes, particularly in September and March. In general, the consistency of performance between the two methods in terms of navigability outcomes deteriorates as the vessel ice class decreases and ice conditions become more complex. This study provides a scientific foundation and data-based support for route planning and real-time decision-making in polar waters. Full article

This study monitored the conditioning of rainbow trout (Oncorhynchus mykiss) broodstock in a closed culture system at 3000 m above sea level (m.a.s.l.) to evaluate the feasibility of this culture method and assess the first spawning of the species under these conditions as an alternative production route for the communities present in the foothills of Cordillera de los Andes, northern Chile. A total of 120 specimens with an initial weight of 170 g were used. They were maintained in a recirculation aquaculture system (RAS) composed of protected circular tanks, decanters, a biofilter, and oxygenation equipment. Fish growth was monitored through parameters such as specific growth rate (SGR), feed conversion ratio (FCR) and percent weight growth (PWG), parameters that were maintained within those reported by other authors for this species. The first successful spawning occurred after 12 months of broodstock conditioning, yielding 8570 eggs, of which 6569 hatched successfully. The success of this conditioning and spawning not only broadens the understanding of adaptability to high-altitude environments, but also provides evidence for the potential diversification of productive activities in foothill areas through aquaculture. Full article

The Bohai Sea is the only semi-enclosed inland sea in China. With active marine economic activities, it faces a persistently high risk of oil spill accidents. This study assesses the occurrence risk and pollution risk of oil spills by considering factors such as sea state, the location of oil platform, and shipping route density in the Bohai Sea. The results show that the central part of the Bohai Sea, the southern Liaodong Peninsula, and the Bohai Strait area have a relatively high occurrence risk of oil spills due to busy maritime traffic and harsh sea conditions. In contrast, some areas in the northern, western, and southern parts of the Bohai Sea have a relatively low occurrence risk of oil spills because of weak maritime activity intensity and relatively calm sea state. In terms of the oil pollution risk, its distribution in the Bohai Sea shows significant seasonal characteristics, which are mainly comprehensively affected by multiple dynamic factors such as circulation, monsoon, and seawater exchange. Based on the oil pollution risk distribution, seasonally targeted strategies are proposed, which can provide a scientific basis for oil spill prevention and emergency management in the Bohai Sea, and help relevant departments formulate targeted prevention and control strategies. Full article

A graphical clustering approach was used to objectively identify prevalent surface circulation patterns in the East/Japan Sea (EJS). By applying a spectral clustering algorithm, three distinct patterns in the East Korea Warm Current (EKWC) and its extension were identified from daily maps of reanalyzed sea surface heights spanning the past 30 years. The results are consistent with previous studies that used manual classification of the EKWC’s Lagrangian trajectories, highlighting the effectiveness of spectral clustering in accurately characterizing the surface circulation states in the EJS. Notably, the recent dominance of northern paths, as opposed to routes along Japan’s coastline or those departing from Korea’s east coast further south, has prompted focused re-clustering of the northern paths according to their waviness. This re-clustering, with additional emphasis on path length, distinctly categorized two patterns: straight paths (SPs) and large meanders (LMs). Notably, SPs have become more prevalent in the most recent years, while LMs have diminished. An autoregression analysis reveals that seasonal anomalies in the cluster frequency in spring tend to persist through to the following autumn. The frequency anomalies in the SPs correlate strongly with the development of pronounced anomalies in the gradient of meridional sea surface height and negative anomalies in the surface wind stress curl in the preceding cold seasons. This relationship explains the observed correlation between a negative Arctic Oscillation during the preceding winter and the increased frequency of SPs in the subsequent spring. The rapid increase in the occurrence of SPs indicates that a reduction in LMs limits the mixing of cold, fresh, northern waters with warm, saline, southern waters, thereby reinforcing the presence of SPs due to a strengthened gradient of meridional surface height and contributing to a slowdown in the regional overturning circulation. Full article

One of the basic features of shamanic rituals cross-culturally in East and Southeast Asia is that the ritual itself is structured as a journey up to the sky, climbing the world mountain or the world tree, or else a journey down to the bottom of the sea and back again. The shamanic retinue is understood to make this journey in person, rather than, as in Daoist ritual, sending divine emissaries up to the highest heavens. The journey is conducted through narrative song and dance, accompanied by strings of bells and lutes. The point of departure is the physical village or village household where the ritual is being conducted, and the journey progresses through a series of well-marked way stations via the temple of the earth god to the higher hills and finally to the villages and markets in the sky, before crossing the heavenly seas and ascending the highest mountain. On the way, demons and other impediments are encountered. The route and way stations vary depending on the purpose of the ritual and the intended divine recipient of offerings and submissions. The present article will explore the route up to the sky and the way stations in more detail, taking a single ritual type as performed by the Pụt and Then ritual practitioners as an example. The Pụt and Then are literate ritual specialists found among the Tày and Nùng peoples in northern Vietnam and southern China, near an area which is known to have been a centre of Brahmanical and Buddhist learning from very early times. Full article

As Arctic sea ice continues to melt and global demand for clean energy rises, Russia’s Liquefied Natural Gas (LNG) exports via the Northern Sea Route (NSR) are rapidly increasing. To ensure the operational safety of LNG carriers and safeguard the economic interests of stakeholders, including shipowners, a thorough assessment of the navigability of various ice-class LNG carriers along this route is essential. This study collected Arctic ice condition data from 2014 to 2023 and applied the Polar Operational Limit Assessment Risk Indexing System (POLARIS) methodology to calculate the Risk Index Outcome (RIO) for LNG carriers with No Ice Class, Arc4, and Arc7 ice classifications in Arctic waters. A navigability threshold of 95% RIO ≥ 0 was established to define navigable windows, and critical waters were identified where sections of the route remain in hazardous or risky conditions year-round. The results indicate that for No Ice Class vessels, Arc4 vessels, and Arc7 vessels, the navigable windows for westbound Route 1 and Route 2 under light, normal, and heavy ice conditions range from 70 to 133 days, 70 to 365 days, and 70 to 365 days, respectively, while for eastbound Route 3, the navigable windows range from 0 to 84 days, 0 to 238 days, and 7 to 365 days, respectively. The critical waters affecting the navigability of No Ice Class vessels, Arc4 vessels, and Arc7 vessels are primarily located in the Kara Sea, Laptev Sea and East Siberian Sea. This study, using the POLARIS methodology, provides valuable insights into the navigability of LNG carriers with different ice classes along the NSR, supporting the development and utilization of Arctic energy and shipping routes while offering decision-making support for stakeholders involved in Arctic maritime operations. Full article

In the winter of 2023/2024, the mass death of swans was observed on Lake Karakol on the eastern coast of the Caspian Sea. From 21 December 2023 to 25 January 2024, 1132 swan corpses (Cygnus olor, Cygnus cygnus) were collected and disposed of on the coast by veterinary services and ecologists. Biological samples were collected from 18 birds for analysis at different dates of the epizootic. It was found that the influenza outbreak was associated with a high concentration of migrating birds at Lake Karakol as a result of a sharp cold snap in the northern regions. At different dates of the epizootic, three avian influenza A/H5N1 viruses of clade 2.3.4.4.b were isolated from dead birds and identified as highly pathogenic viruses (HPAIs) based on the amino acid sequence of the hemagglutinin multi-base proteolytic cleavage site (PLREKRRRKR/G). A phylogenetic analysis showed that the viruses isolated from the swans had reassortations in the PB2, PB1, and NP genes between highly pathogenic (HP) and low-pathogenic (LP) avian influenza viruses. Avian influenza viruses A/Cygnus cygnus/Karakol lake/01/2024(H5N1) and A/Mute swan/Karakol lake/02/2024(H5N1) isolated on 10 January 2024 received PB2, PB1, and NP from LPAIV, while A/Mute swan/Mangystau/9809/2023(H5N1) isolated on 26 December 2023 received PB1 and NP from LPAIV, indicating that the H5N1 viruses in this study are new reassortants. All viruses showed amino acid substitutions in the PB2, PB1, NP, and NS1 segments, which are critical for enhanced virulence or adaptation in mammals. An analysis of the genomes of the isolated viruses showed that bird deaths during different periods of the epizootic were caused by different reassortant viruses. Kazakhstan is located at the crossroads of several migratory routes of migratory birds, and the possible participation of wild birds in the introduction of various pathogens into the regions of Kazakhstan requires further study. Full article

Cities are in constant development, both structurally and demographically, necessitating careful planning to enhance their orderliness and livability. This research focuses on identifying development directions and routes for the Kyrenia White Zone, situated between the sea and the mountains in northern Cyprus, a significant tourist area. The rapid implementation of zoning laws over different periods has led to swift development and population growth, resulting in various infrastructure challenges, particularly related to transportation. The primary aim of this study is to assess the current infrastructure issues within the zone, understand user perceptions, and identify key factors influencing future growth. Based on the collected data, we propose an alternative growth area for the future development plan of the city. Additionally, this research seeks to explore irregular urban developments and make informed design decisions for their future. Utilizing Space Syntax and GIS as core methodologies, the study employs Space Syntax, a research method developed by Bill Hillier and Julienne Hanson in the 1970s, to analyze human movement and perception. The existing map system of the Kyrenia White Zone was digitized, and essential geographical information was gathered. This data were analyzed using GIS and evaluated through the Space Syntax method. The analysis yielded alternative growth routes that address current challenges within the zone, accompanied by recommendations for enhancing its future development. Full article

With global warming and the gradual melting of Arctic sea ice, the navigation duration of the Northeast Passage (NEP) is gradually increasing. The dynamic changes in sea ice concentration (SIC) during navigation time are a critical factor affecting the navigation of the passage. This study uses multiple linear regression and random forest to analyze the navigation windows of the NEP from 1979 to 2022 and examines the critical factors affecting the dynamic changes in the SIC. The results suggest that there are 25 years of navigable windows from 1979 to 2022. The average start date of navigable windows is approximately between late July and early August, while the end date is approximately early and mid-October, with considerable variation in the duration of navigable windows. The explanatory power of RF is significantly better than MLR, while LMG is better at identifying extreme events, and RF is more suitable for assessing the combined effects of all variables on the sea ice concentration. This study also found that the 2 m temperature is the main influencing factor, and the sea ice movement, sea level pressure and 10 m wind speed also play a role in a specific period. By integrating traditional statistical methods with machine learning techniques, this study reveals the dynamic changes of the SIC during the navigation period of the NEP and identifies its driving factors. This provides a scientific reference for the development and utilization of the Arctic Passage. Full article

A large amount of cargo is transported between European and Southeast Asian countries. Ships sometimes take different routes when sailing between ports due to the best commercial speed; navigational, economical, and hydrometeorological conditions; and political and military situations. Several routes are available for sailing between Europe and Southeast Asia: sailing the Suez Canal, sailing around the African continent, sailing the Panama Canal, as well as sailing the Northern Sea route. This article analyzes the possible sailing routes between Southeast Asia and Europe and presents a developed methodology for the evaluation of sailing routes. This sea route evaluation methodology is based on a comparative mathematical model that evaluates the main factors of cargo transportation by sea: transportation cost and time, possible maximum ship parameters, transportation energy (fuel) demand, and other possible factors, such as the probability of various restrictions. This paper presents a case study of cargo transportation between Rotterdam (The Netherlands) and Shanghai (China) using different possible sea routes. Assessments of various possible routes are presented; the main topics of discussion and conclusions are formulated. Full article

The desert locust, Schistocerca gregaria (Forsk., 1775), stands as one of the most pervasive pests globally, inflicting extensive damage across Asia and Africa. Facilitated by intercontinental migration, the desert locust engages in population exchange between different source areas, perpetuating its widespread proliferation. Despite the wind being recognized as a key factor during migration events, elucidating its precise influence on intercontinental migration has remained elusive. In this study, we scrutinized monitoring data sourced from the FAO monitoring system, pinpointing 13 desert locust events featuring intercontinental migrations since 1967. From these events, four migration routes were summarized, traversing the Red Sea (RS-WE and RS-EW) and the northern Indian Ocean (IO-WE and IO-EW). Typically, RS-WE and IO-EW migrations occurred between December and March, whereas RS-EW and IO-WE migrations were observed from May to June and April to July, respectively. Our examination of wind field data spanning the past 15 years revealed that wind direction and speed facilitated intercontinental migrations. Furthermore, migration trajectory modeling indicated that desert locusts might exhibit migratory behavior both during the day and at night in the cases of RS-WE and RS-EW, with cross-oceanic migration potentially lasting for a week for IO-WE and IO-EW. In summary, our study identifies four migration routes for the intercontinental migration of the desert locust, providing crucial support for the scientific prediction of its occurrence and contributing to international food security efforts. Full article

With the accelerated melting of the Arctic sea ice, the opening of the Northern Sea Route (NSR) of the Arctic is becoming increasingly accessible. The purpose of this paper was to examine the impact of uncertainty in sea ice thickness (SIT) data on the opening of the NSR and to quantify the extent of this impact, which is essential to the regularized operation of polar shipping. A quantitative assessment framework was proposed to examine the influence of SIT data uncertainty on navigational uncertainty through three aspects: the navigational spatiotemporal windows, the distribution of safe sailing speeds, and the uncertainty in optimal route planning by employing four distinct SIT datasets. Furthermore, the sensitivity of navigational spatiotemporal windows, the distribution of safe sailing speeds, and route planning to variations in SIT were also evaluated. Results show that experiment results based on CS2SMOS exhibit a more aggressive profile, while results based on CPOM are more conservative. The difference in SIT data has a significant impact on the proportion of operations subject to special consideration areas, such as safety speed, sailing time, and distance in NEP. A 0.1 m discrepancy in sea ice thickness data results in an approximate 0.067 change in the proportion of operations within special consideration areas. This discrepancy also leads to an approximate speed change of 0.89 knots, a navigation duration change of approximately 4 days, and a distance change of 152 km within specified limits. Full article

Sea ice concentration and thickness are key parameters for Arctic shipping routes and navigable potential. This study focuses on the changes in shipping routes and the estimation of navigable potential in the Arctic Northern Sea Route and Transpolar Sea Route during 2021–2050 based on the sea ice data predicted by eight CMIP6 models. The Arctic sea ice concentration and thickness vary among the eight models, but all indicate a declining trend. This study indicates that, under the two scenarios, the least-cost route will migrate more rapidly from the low-latitude route to the high-latitude route in the next 30 years, showing that the Transpolar Sea Route will be navigable for Open Water (OW) and Polar Class 6 (PC6) before 2025, which is advanced by nearly 10 years compared to previous studies. The sailing time will decrease to 16 and 13 days for OW and PC6 by 2050, which saves 3 days compared to previous studies. For OW, the navigable season is mainly from August to October, and the Northern Sea Route is still the main route, while for PC6, the navigable season is mainly from July to January of the following year, and the Transpolar Sea Route will become one of the important choices. Full article

The Arctic zone of the Russian Federation is of strategic importance for the country. Considering the fragility of Arctic ecosystems, special attention needs to be paid to the sustainable development of transport and related infrastructure within the framework of the “blue economy” concept, which is relevant for Arctic waters. At the same time, it is necessary to identify the main factors and tasks of creating transport and port infrastructure, building a modern fleet, and organizing fisheries and tourism in an environmentally sound manner. The purpose of the study is to consider the problems of anthropogenic influence for seaport facilities and to create a conceptual model of an environmental risk management system. The existing problems of Arctic ports and infrastructure are analyzed and existing business processes are considered, taking into account the peculiarities of their functioning in Arctic conditions. To systematize environmental assessments and establish dependencies between the main indicators describing the impact of port activities on elements of the natural environment, ontological domain engineering is proposed. It systematizes the basic terminology used within different subject areas of ecology and risks and allows one to visualize the relationships between elements of the natural environment, objects, port systems, their parameters and impact factors to assess the impact of the seaport on the natural environment. The results of ontological engineering (design and development of ontologies) in the field of risk management are presented. Future research will be aimed at developing the applied aspect of applying the results of ontological engineering in terms of specific engineering studies related to the assessment of anthropogenic load on the Arctic territory using simulation modeling. Full article

The Arctic’s navigation and utilization have garnered global interest due to the economic and strategic significance of its open shipping routes. The feasibility and cost-effectiveness of Arctic wind power generation depend largely on the potential of wind energy, which in turn influences the construction of new ports. In order to effectively harness polar wind energy, we must understand and adapt to its ever-changing rules. This study leverages ERA5′s 40-year wind field data to estimate the Theil–Sen Median slope and perform Mann–Kendall trend analysis. We consider factors such as wind power density, effective wind speed occurrence, energy level frequency, stability, and resource reserves to comprehensively analyze the intergenerational variations in Arctic wind energy resources. Our findings indicate that Northeast Passage, Davis Strait, and Baffin Bay possess favorable wind power density (1~2 W/m²·yr⁻¹), effective wind speed occurrence (0.1~0.2%·yr⁻¹), energy level frequency (0.1~0.2%·yr⁻¹), stability (−0.005 yr⁻¹), and resource reserves (1 kWh/m²·yr⁻¹). However, these indicators are inferior in the Barents Sea, Canada’s northern archipelagos, and Greenland’s vicinity, where wind energy is relatively poor and unfavorable for development. Autumn dominates the annual change trend of Arctic wind energy, while spring and summer show no significant trends. Full article