Northeast Asia Research Articles

Human-Animal Relations and the Hunt in Korea and Northeast Asia

Human-Animal Relations and the Hunt in Korea and Northeast Asia

Epidemiology and Expected Cost of International Medical Repatriation Into South Korea: 2019 to 2021

ObjectiveOverseas Koreans face challenges in accessing adequate medical care abroad. Understanding the epidemiology and costs of international medical repatriation is important. MethodsA retrospective analysis of overseas Korean patients who were repatriated to South Korea between 2019 and 2021 was conducted. The data collected from 121 countries included demographics, medical conditions, and costs. Variables from 9 continents (Southeast Asia, Northeast Asia, Southwest Asia–Pacific, Russia–Central Asia, North America, Central and South America, Europe, Middle East‒North Africa, and Sub-Saharan Africa) and the era of coronavirus disease 2019 (February 2020 and after) were analyzed and compared. Based on the available total cost data, stepwise extrapolation was conducted for the total cohort. ResultsA total of 428 overseas Korean patients who had undergone international medical repatriation via air transport were included in this study. The greatest number of repatriated patients were from Southeast Asia (108 patients), and 279 patients were transported within the coronavirus disease 2019 era. The average cost per patient exceeded $7,000, and the total cost estimated by extrapolation was over $8 million. ConclusionInternational medical repatriation is significant for overseas Koreans. Standardized guidelines and system development are essential for effective air medical services.

Spatiotemporal distribution of global wind erosion over the past four decades

Abstract Wind erosion is a critical environmental issue that degrades land and air quality, affecting global ecosystems, agriculture, and human health. Yet, on the global scale, the long-term spatial variability and controlling factors of wind erosion remain highly uncertain. Here, we develop a high-resolution spatiotemporal dataset of global wind erosion from 1980 to 2020 using the Revised Wind Erosion Equation model, integrated with comprehensive meteorological, terrestrial ecology, and soil datasets. Our analysis indicates that wind erosion annually impacted 359 ± 25 petagrams of soils worldwide during this period. Approximately 70% of this erosion occurred in just ten countries, predominantly in Africa and the Middle East. Due to higher erosion intensities, pasturelands, accounting for 28% of all non-barren land use types, disproportionately contributed to 70% of the erosion in these areas. Furthermore, our analysis highlights an upward trend in global wind erosion over the past four decades, with affected areas expanding worldwide. Although our study reinforces that changing wind speeds and a drier climate are central factors impacting global wind erosion, we find that increasing erosion intensities in pasturelands may also exacerbate erosion in North Africa, South America, and East Asia. This has broad implications for soil erosion issues that impact food productivity, human health, and ecosystem stability. This research provides insights for developing wind erosion warnings and targeted mitigation strategies, supporting global efforts to combat environmental degradation and promote sustainable development.

Distinct Features of Tropical Cyclone Landfall over East Asia during Various Types of El Niño

Abstract Numerous studies focus on the impacts of ENSO diversity on tropical cyclone (TC) activities in the western North Pacific (WNP). In recent years, there is a growing threat of landfalling and northward-moving TCs in East Asia, accompanying an increase in central Pacific (CP) El Niño. Here, we aim to discover variations in landfalling TCs during various types of CP El Niño (CP-I and CP-II El Niño). It is found that significant changes in landfalling and going northward TCs over East Asia north 20°N are modulated by CP-I El Niño. During CP-I El Niño, TCs tend to landfall more often over the mainland of China with longer duration, moving distance, and stronger power dissipation index (PDI) after landfall and increased TC-induced rainfall, due to favorable conditions (beneficial steering flow, weak vertical wind shear, increased specific humidity, increased soil moisture, and temperature), especially significant over the northeastern part. The situation over the mainland of China is reversed during eastern Pacific (EP) El Niño and CP-II El Niño, with a significant decrease in the characteristics with corresponding unfavorable environments. Over the Korean Peninsula and Japan, the frequency of TC landfalls, as well as the duration and the moving distance after landfall, exhibits greater levels during CP-I and CP-II El Niño than during EP El Niño due to favorable steering flow, and thus, TC-induced rainfall enhances correspondingly. Regarding the PDI over the Korean Peninsula and Japan, it remains relatively consistent across all El Niño types. However, a notable increase in the PDI during EP El Niño could be attributed to the higher intensity of TCs prior to landfall.

Warm-temperate evergreen pterophytes of Korea

Korean evergreen fern species that prefer warm-temperate forests as their main habitats are categorized into three groups according to their present distributions: group I, tropic-originating species; group II, Himalaya-originating species; and group III, endemic to warm-temperate regions of Northeast Asia. Due to global warming, a northward expansion of the species belonging to the group III is expected. New habitats of rare evergreen ferns, Crepidomanes latealatum and Haplopteris flexuosa, were found on the Haenam Peninsula, expanding their known Korean habitat from Jejudo Island.

THE ROLE OF MONGOLIA IN REGIONAL SECURITY

The situation in Northeast Asia is an important topic of international security arena. Political and economic relations between Russia and China, as well as the Korean Peninsula issue, which can have a major impact in Northeast Asia as such powerful actors that can change the world order and security environment. Past decades, the peace policy of mutual trust between the countries of the Northeast Asian region has become the most important issue not only in the regional but also in the international security environment. Therefore, it is important to analyze and assess a strategic interests and international geopolitical ambition of major powers that could directly or indirectly affect Mongolia's national security to develop national strategic solutions to enhance Mongolia’s national security and its security environment. Mongolia has no territorial, economic, military or political conflicts of interest with any of the countries in the region. Such reasons can give Mongolia an opportunity to be a key player in confidence-building measures to prevent hostilities, to avert escalation, to reduce military tension in Northeast Asia. There are many ways and fields to operate as peace player in this region. For instance, Mongolia can be an initiator or a main actor of a regional peacekeeping cooperation organization in Northeast Asia.

The Enhancement of the East Asian Summer Monsoon over Northeast Asia over the Most Recent Two Decades

The Enhancement of the East Asian Summer Monsoon over Northeast Asia over the Most Recent Two Decades

Challenges to the Capacity-Building of Maritime Domain Awareness (MDA) in East Asia: What Is at Stake?

East Asian countries, including Northeast Asian countries such as China, Japan and Korea, and Southeast Asian countries such as the Philippines, Malaysia, Indonesia and Singapore, have endeavored to enhance their maritime domain awareness (MDA) capabilities at either the state or regional level to mitigate, prevent or respond to maritime threats. Vibrant, dynamic East Asia comprises a huge diversity of cultures, religions, political systems, and security regimes, and their perceptions of and approaches to MDA are significantly varied. The regional states need to recognize the importance and value of MDA in ensuring maritime safety and security and to allocate more resources to build up their MDA capacities accordingly. In addition, closer collaboration between Northeast and Southeast Asian countries is required.

Detrital Zircons From Lower Palaeozoic Metamorphic Complexes and Silurian–Devonian Strata in the South Kitakami Belt, Northeast Japan: Implications for the Northern Extension of the Terra Australis Orogen in Northeast Gondwana

ABSTRACTTo reconstruct the detailed location of proto‐Japan around northeastern Gondwana during the early Palaeozoic, this article presents detrital zircon U–Pb age spectra for lower Palaeozoic metamorphic complexes and Silurian–Devonian strata from the western margin of the South Kitakami belt in northeast Japan. Psammitic and siliceous schists have youngest age peaks ranging from the Ordovician (479–458 Ma) to early Silurian (ca. 439 Ma). Sandstones have youngest age peaks varying from the early Silurian (ca. 435 Ma) to Late Devonian (370–360 Ma). The U–Pb age spectra exhibit major peaks at 510–500, 480–470, and 450–440 Ma. Excluding the Upper Devonian sandstones, significant age peaks occur at 650–550 and 1300–900 Ma. These data can be interpreted as a Pacific Gondwana signature, indicating a tectonic association with the Terra Australis Orogen that developed along the northeastern Gondwanan margin and Paleo‐Pacific Ocean, extending from eastern Australia (i.e., the Thomson, Lachlan, and Delamerian orogens) to Antarctica (i.e., the Ross Orogen). In northeast Asia, the Pacific Gondwana detrital zircons and 480–470 Ma zircons occur in the Bainaimiao arc belt along the northern margin of the North China Craton and in the Jiangyu continental arc in the Jilin area. The magmatic arcs of proto‐Japan and these regions were part of the Terra Australis Orogen during the Ordovician–early Silurian. A decrease in the proportion of Pacific Gondwana detrital zircons in Upper Devonian strata may be due to multistage trench retreat, such as that recognized in the Tasmanides in eastern Australia, which corresponds to the northern Terra Australis Orogen.

Assessing Environmental Sustainability in the Transnational Basin of the Tumen River Based on Remote Sensing Data and a Geographical Detector

Evaluating environmental sustainability in the transnational basin of the Tumen River (TBTR) is of great significance for promoting sustainable development in Northeast Asia. However, past research has mostly concentrated on a particular environmental element, making it impossible to thoroughly and effectively show the environmental sustainability dynamics in this transnational area. In this study, we attempted to reveal environmental sustainability trends in the TBTR from 2000 to 2021 using the Environmental Degradation Index (EDI) and analyze the driving forces using a geographical detector. It was found that the TBTR’s environmental sustainability decreased significantly, with a degraded region (13,174.75 km2) accounting for 31.01% of the whole area from 2000 to 2021. The dynamics of environmental sustainability on the three sides of China, the Democratic People’s Republic of Korea (DPRK), and Russia have shown significant differences, with the most significantly improved in environmental sustainability being the subregion of China. On the Chinese side, the area that significantly improved in environmental sustainability accounted for 26.19% of the area on the Chinese side, which was 1.17 times higher than that of the DPRK’s side and 1.24 times higher than that of the Russian side. Land use intensity (LUI), land use and land cover (LULC), and population density (PD) were the most dominant driving forces for environmental sustainability dynamics on the three sides of China, the DPRK, and Russia. China, the DPRK, and Russia can improve international environmental cooperation to promote sustainable development in the TBTR and Northeast Asia.

Monthly Characteristics and Source–Receptor Relationships of Anthropogenic Total Nitrate in Northeast Asia

The complex nonlinear characteristics of atmospheric chemistry necessitate the development of new methods for calculating source–receptor (S–R) relationships for secondary air pollutants. In this study, the monthly characteristics and S–R relationships of anthropogenic total nitrate (i.e., the sum of N from nitric acid, inorganic nitrate, and peroxyacetyl nitrate) in Northeast Asia were simulated and analyzed. The Community Multiscale Air Quality (CMAQ), Fifth-Generation NCAR/Penn State Mesoscale (MM5), and Sparse Matrix Operator Kernel Emissions (SMOKE) models were employed for air quality modeling, meteorological fields, and emissions processing, respectively. The study area encompassed Republic of Korea, Japan, and most of China. Five source/receptor regions were defined to derive the S–R relationships: three in China, one in Republic of Korea, and one in Japan. To produce data for the calculation of the S–R relationship, several experiments were conducted with a 20% reduction in NOx emission sources. As a result of the S–R relationships, China was rarely impacted by the other two countries. The total depositions in other countries were significantly dominated by China (i.e., 43.5% and 40.7% in Republic of Korea and Japan, respectively, and up to 82.3% in December for Republic of Korea).

Climatic and disturbances influence on tree-rings of Larix gmelinii in the southeast coastal area

The vast region of North East Asia is covered by primary mixed conifer-broadleaved forests which include a range of different tree species. A key factor in the dynamics of these ecosystems is wind disturbance. According to reports, this factor will be increasingly important as a result of the poleward migration of tropical cyclones, a characteristic of which is strong wind. At the same time, global climate change may reduce the recovery potency of some species and lead to new combinations of species. Gmelin Larch is one of the key early succession species in the north of the region. In the southeastern part of its range (Russian Far East), this species has not been widely studied by dendroclimatologists and there are no dendroecological studies available. This study shows how the seasonal growth of Larix gmelinii responds to changes in climate, specifically to variations in precipitation and temperature. The study has established that these trees are more affected by rising temperatures than by consistent precipitation levels, provided there is no shortage of water. Interestingly, after the 1970s there was a change in the climate sensitivity of Larix gmelinii in June (the month with the strongest correlation). It went from a negative correlation with temperature to a positive correlation with precipitation. By using tree ring data, we were able to reconstruct the past history of forest disturbance. The peaks in this chronology coincide with those in earlier published dendroecological reconstructions for other species. They indicate that the radial growth of larch is sensitive to canopy changes. We recorded two release peaks in the 1960s and 2000s, during the period of meteorological observations. We attributed the first peak to the most powerful tropical cyclone Emma (1956). We assume also that the second peak reflects the recent intensification of tropical cyclones in the region. In our opinion, the change in microclimate as a result of disturbance has altered the relationship to climate in such a way that disturbance may cause tree growth to be dependent on precipitation. At the same time, such low correlations do not support a conclusion about the strong negative influence of the current climate on the trees.

Rapakivi granites and associating magmatism during the Aptian development stage of the Siberian craton active continental margin (northeast Asia)

Rapakivi granites and associating magmatism during the Aptian development stage of the Siberian craton active continental margin (northeast Asia)

Increasing cross-border dust storm from Mongolia to China during 1987–2022

Mongolia and northern China have the highest frequency of dust weather in Northeast Asia. Dust transport from Mongolia to China is a major cause of dust weather in northern China. However, there has been limited research on the frequency changes of cross-border dust storms from Mongolia to China over the past few decades. Based on observational data, we analyzed the variation in cross-border dust storms between China and Mongolia during 1987–2022. The results indicate that, on average, approximately seven cross-border dust storm events occur annually between China and Mongolia, predominantly during the spring. The frequency of cross-border dust storms from Mongolia to China significantly increased from 2.2 events in P1 (1987–1999) to 7.5 events in P2 (2000−2022). Long-term trends suggest that rising dust emissions in east-central Mongolia largely contributed to this increase. The increase in cross-border dust storms from Mongolia to China in the spring was driven by more frequent cyclones in eastern Mongolia and Northeast China during P2. This is evidenced by a negative height anomaly and increased vorticity at 850 hPa over Northeast China. The cyclones were linked to the northward shift of the East Asian Polar Front Jet Stream (EAPJ) at 300 hPa between 50°N and 60°N. Additionally, surface conditions such as higher temperatures and decreased vegetation in Mongolia contributed to the increased frequency of cross-border dust storms from P1 to P2.

Analysis of the Impact of U.S.-South Korean Military Activities on the DPRK's Nuclear Test Process

After the end of World War II, the Korean Peninsula was divided into two, and then the Korean War broke out, and the two Koreas were still in a state of "armistice." The North Korean nuclear issue and the large-scale U.S.-South Korean joint military exercises that have lasted for decades have made the situation in Northeast Asia, which is already in a security dilemma, even more complicated and volatile. By analyzing the timing of North Korea's nuclear tests and their backgrounds, it is easy to find that North Korea has never stopped researching nuclear weapons. However, every nuclear test has been conducted against the background of large-scale U.S.-South Korea joint military exercises. On the issue of resolving the DPRK's nuclear crisis, it is worth rethinking the way of resolving the DPRK's nuclear issue through sanctions and pressure. A study of the relationship between the DPRK's nuclear test and the U.S.-South Korea joint military exercises will help to ease the security dilemma between the two sides as well as the security situation in Northeast Asia. It will also serve as a reference for other nuclear proliferation issues in the international arena.

Importance of Intraseasonal Oscillation for the Regional Extreme Consecutive dry Days Events in Spring Over Southern China

AbstractThis study investigates the influences of intraseasonal oscillation on two types of regional extreme consecutive dry days events (RECDD) in spring over Southern China (SC). For type‐1 RECDD occurring in entire SC, the 7–25 days and 25–90 days high over Lake Balkhash‐Baikal are important. The 7–25 days high first causes lower‐tropospheric northerlies and moisture deficit in SC, then propagates to Yangtze River Basin and causes lower‐tropospheric warming and decaying moisture deficit in SC. These processes favor dry condition in SC for 1 week. In comparison, the 25–90 days high and associated lower‐tropospheric warming and moisture deficit in SC favor dry condition there for more than one week. For type‐2 RECDD occurring in the southern part of SC, the 7–25 days and 25–90 days high over Northeast Asia are important. The 7–25 days high contributes for one week. It first causes lower‐tropospheric anticyclone around the East China Sea and south‐negative–north‐positive moisture pattern in SC, then propagates to the Sea of Japan and causes lower‐tropospheric south‐warming–north‐cooling pattern and decaying south‐negative–north‐positive moisture pattern in SC. In comparison, the 25–90 days high and associated lower‐tropospheric south‐warming–north‐cooling pattern and south‐negative–north‐positive moisture pattern in SC favor south‐dry–north‐wet pattern there for more than one week. Moreover, the 7–25 days low and decaying 25–90 days high over Lake Balkhash‐Baikal, concurring with 7–25 days low over Bay of Bengal, favor the end of type‐1 RECDD; the 7–25 days low and decaying 25–90 days high over Northeast Asia favor the end of type‐2 RECDD.

Microbial richness and air chemistry in aerosols above the PBL confirm 2,000-km long-distance transport of potential human pathogens

The existence of viable human pathogens in bioaerosols which can cause infection or affect human health has been the subject of little research. In this study, data provided by 10 tropospheric aircraft surveys over Japan in 2014 confirm the existence of a vast diversity of microbial species up to 3,000 m height, which can be dispersed above the planetary boundary layer over distances of up to 2,000 km, thanks to strong winds from an area covered with massive cereal croplands in Northeast (NE) Asia. Microbes attached to aerosols reveal the presence of diverse bacterial and fungal taxa, including potential human pathogens, originating from sewage, pesticides, or fertilizers. Over 266 different fungal and 305 bacterial genera appeared in the 10 aircraft transects. Actinobacteria, Bacillota, Proteobacteria, and Bacteroidetes phyla dominated the bacteria composition and, for fungi, Ascomycota prevailed over Basidiomycota. Among the pathogenic species identified, human pathogens include bacteria such as Escherichia coli, Serratia marcescens, Prevotella melaninogenica, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus saprophyticus, Cutibacterium acnes, Clostridium difficile, Clostridium botulinum, Stenotrophomonas maltophilia, Shigella sonnei, Haemophillus parainfluenzae and Acinetobacter baumannii and health-relevant fungi such as Malassezia restricta, Malassezia globosa, Candida parapsilosis and Candida zeylanoides, Sarocladium kiliense, Cladosporium halotolerans, and Cladosporium herbarum. Diversity estimates were similar at heights and surface when entrainment of air from high altitudes occurred. Natural antimicrobial-resistant bacteria (ARB) cultured from air samples were found indicating long-distance spread of ARB and microbial viability. This would represent a novel way to disperse both viable human pathogens and resistance genes among distant geographical regions.

Development of a Simple Observation System to Monitor Regional Wind Erosion

Dryland occupies about 46% of the global land surface area (except Antarctica) and is the most vulnerable area to climate change. From the conditions of vegetation and land surface wetness and blown sand phenomena, a simple observation system was developed to monitor regional wind erosion and applied to Khuld of Mongolia, which is sensitive to drought and desertification. The system was composed of instruments that observed blown sand, vegetation amount, land surface wetness, and landscape features related to regional wind erosion. Sixteen blown sand and eight sandstorm events were evaluated from 5 March to 5 June 2023 (i.e., during the Asian dust season in northeast Asia). The normalized difference vegetation index and visible images showed that the vegetation amount was considerably less, and the developed moisture index related to land surface wetness indicated dry conditions. Combining the results of blown sand, these indices, and visible images, land surface conditions during the analysis period were likely to occur with blown sand events.

Maritime transportation risk assessment: A multilevel node relationship-based fuzzy bayesian network

Maritime transportation safety has encountered unprecedented challenges arising from abrupt changes in various risk attributes in recent years, including natural weather and non-traditional security threats. This study presents a novel two-phase framework for assessing the maritime transportation risk. Firstly, a fuzzy Bayesian network considering multi-level node relationships was constructed to more accurately assess the transportation risk in various sea areas. In the second phase, RF-Shapley was developed to identify crucial risk nodes that exert substantial influence on transportation risk within individual sea areas. The results showed that transportation risk was the lowest in the South Asian and the highest in the Middle East waters. Critical risk nodes were different for each sea area, such as pirate attack node in Southeast Asian waters, extreme weather node in Northeast Asia, changing these nodes would be more helpful in improving transportation safety. Moreover, the contribution of critical risk nodes exhibited variations, such as combating terrorism and piracy were more conducive to reducing transportation risk in Middle Eastern waters, while ship accidents node be low contribution. These results offer valuable insights for evaluating transportation risk in uncertain environments and can serve as a reference for stakeholders to devise tailored policies and action plans.

Implications for extreme midlatitude weather events of secondary flow associated with polar jets

AbstractIn the Earth's general circulation, polar jets act as baroclinic pumps of angular momentum and heat. Reanalysis datasets indicate that shear changes near jets induce upward displacements of the jet cores, suggesting a weakening thermodynamic pumping over the last 50 years. From secondary flow theory, a well‐established principle in fluid dynamics, an increased frequency of heatwaves and persistent winter storms is expected. The ageostrophic wind shear between 700 and 50 hPa indicates the strength of this secondary circulation. The weakening tendency during the reanalysis period also exists in multimodel simulations under the RCP8.5 emissions scenario for the 21st century. The reduction between the periods 2005–2025 and 2081–2100 reaches 18%, 5.3% and 19%, respectively, for the North America, Mid‐Europe and East Asia sectors of the Northern Hemisphere polar jet. Within this background, cold‐surge events are the result of synergic co‐working of several factors. The occurrence trend for transitional season winter extreme events also is examined. The winter extremes seemingly have larger temperature drops. However, in a warming climate, they emerge more rapidly from extreme cold states. The storm tracks, especially over North America, have equatorward extensions, indicating that winter storms can reach lower latitudes. Due to the temperature‐dependence of air viscosity, secondary flows decrease more slowly than the main zonal flow. This imposes an important adjustment to the traditional polar amplification effects on midlatitude winter extremes. During a warmer winter (the primary manifestation of a warmer climate), spatially uniform positive trends in cold extreme events are not expected. There are, however, regions experiencing more winter extremes. These regions show consistent patterns in both the reanalysis period and the remainder of the 21st century.