Korean Peninsula Research Articles

Post-Processing Maritime Wind Forecasts from the European Centre for Medium-Range Weather Forecasts around the Korean Peninsula Using Support Vector Regression and Principal Component Analysis

Accurate wind data are crucial for successful search and rescue (SAR) operations on the sea surface in maritime accidents, as survivors or debris tend to drift with the wind. As maritime accidents frequently occur outside the range of wind stations, SAR operations heavily rely on wind forecasts generated by numerical models. However, numerical models encounter delays in generating results due to spin-up issues, and their predictions can sometimes exhibit inherent biases caused by geographical factors. To overcome these limitations, we reviewed the observations for the first 24 h of the 72-hour forecast from the ECMWF and then post-processed the forecast for the remaining 48 h. By effectively reducing the dimensionality of input variables comprising observation and forecast data using principal component analysis, we improved wind predictions with support vector regression. Our model achieved an average RMSE improvement of 16.01% compared to the original forecast from the ECMWF. Furthermore, it achieved an average RMSE improvement of 5.42% for locations without observation data by employing a model trained on data from the nearest wind station and then applying an adaptive weighting scheme to the output of that model.

Elevational Variation in and Environmental Determinants of Fungal Diversity in Forest Ecosystems of Korean Peninsula.

Exploring species diversity along elevational gradients is important for understanding the underlying mechanisms. Our study focused on analyzing the species diversity of fungal communities and their subcommunities at different trophic and taxonomic levels across three high mountains of the Korean Peninsula, each situated in a different climatic zone. Using high-throughput sequencing, we aimed to assess fungal diversity patterns and investigate the primary environmental factors influencing fungal diversity. Our results indicate that soil fungal diversity exhibits different elevational distribution patterns on different mountains, highlighting the combined effects of climate, soil properties, and geographic topology. Notably, the total and available phosphorus contents in the soil emerged as key determinants in explaining the differences in diversity attributed to soil properties. Despite the varied responses of fungal diversity to elevational gradients among different trophic guilds and taxonomic levels, their primary environmental determinants remained remarkably consistent. In particular, total and available phosphorus contents showed significant correlations with the diversity of the majority of the trophic guilds and taxonomic levels. Our study reveals the absence of a uniform diversity pattern along elevational gradients, underscoring the general sensitivity of fungi to soil conditions. By enriching our understanding of fungal diversity dynamics, this research enhances our comprehension of the formation and maintenance of elevational fungal diversity and the response of microbial communities in mountain ecosystems to climate change. This study provides valuable insights for future ecological studies of similar biotic communities.

The Korean infrasound catalogue (1999–2022)

SUMMARY The Korean infrasound catalogue (KIC) covers 1999–2022 and characterizes a rich variety of source types as well as document the effects of the time-varying atmosphere on event detection and location across the Korean Peninsula. The KIC is produced using data from six South Korean infrasound arrays that are cooperatively operated by Southern Methodist University and Korea Institute of Geoscience and Mineral Resources. Signal detection relies on an Adaptive F-Detector that estimates arrival time and backazimuth, which draws a distinction between detection and parameter estimation. Detections and associated parameters are input into a Bayesian Infrasonic Source Location procedure. The resulting KIC contains 38 455 infrasound events and documents repeated events from several locations. The catalogue includes many anthropogenic sources such as an industrial chemical explosion, explosions at limestone open-pit mines and quarries, North Korean underground nuclear explosions and other atmospheric or underwater events of unknown origin. Most events in the KIC occur during working hours and days, suggesting a dominance of human-related signals. The expansion of infrasound arrays over the years in South Korea and the inclusion of data from the International Monitoring System infrasound stations in Russia and Japan increase the number of infrasound events and improve location accuracy because of the increase in azimuthal station coverage. A review of selected events and associated signals at multiple arrays provides a location quality assessment. We quantify infrasound events that have accompanying seismic arrivals (seismoacoustic events) to support the source type assessment. Ray tracing using the Ground-to-Space (G2S) atmospheric model generally predicts observed arrivals when strong stratospheric winds exist, although the predicted arrival times have significant discrepancies. In some cases, local atmospheric data better captures small-scale variations in the wind velocity of the shallow atmosphere and can improve arrival time predictions that are not well matched by the G2S model. The analysis of selected events also illustrates the importance of topographic effects on tropospheric infrasound propagation at local distances. The KIC is the first infrasound catalogue compiled in this region, and it can serve as a valuable data set in developing more robust infrasound source localization and characterization methods.

Complete chloroplast genome of Asarum chungbuensis (C.S. Yook & J.G. Kim) B.U. Oh 2005 (Aristolochiaceae), a Korean endemic species

Asarum chungbuensis, a species endemic to Korea, has a limited distribution across the Korean Peninsula and is used in traditional medicine. Despite its importance, the genome structure, genetic composition, and phylogenetic relationships based on its chloroplast genome have not been documented. In this study, the complete chloroplast genome of A. chungbuensis was newly assembled. The chloroplast genome is 190,179 base pairs (bp) long, and the overall GC content (%) of the plastid was 36.8%. The chloroplast genome size of A. chungbuensis is longer than that of the normal chloroplast genome (160 kb) because of an inverted small single-copy (SSC) duplication that incorporates the SSC into an inverted repeat (IR) region. By extension, this duplication event causes this chloroplast genome to lack an SSC, unlike other formal structures. The chloroplast genome, with a tripartite structure, consisted of a single-copy region of 93,351 bp with a 34.6% GC content and two IR regions, each with a length of 48,414 bp and a 38.8% GC content. Additionally, it was found to have 113 genes, including 79 PCG genes, 30 tRNA genes, and four rRNA genes. Phylogenetic analysis revealed that A. chungbuensis was grouped with A. heterotropoides var. seoulense, which diverged from the clade comprising A. koreanum and A. patens. The newly sequenced A. chungbuensis chloroplast genome could provide valuable genomic information for determining unique genome structures, especially for the assessment of genetic diversity, phylogenetic relationships, species conservation, and biogeographic studies of the genus Asarum.

Enhanced Mid-to-Late Summer Precipitation over Midlatitude East Asia under Global Warming

Abstract East Asian summer monsoon precipitation is projected to increase under greenhouse warming with strong intraseasonal variation. Using a 35-member CESM Large Ensemble and 30 CMIP6 models, this study reveals that in July and August, maximum rainfall changes in East Asia take place in the midlatitudes, influencing regions encompassing North and Northeast China, the Korean Peninsula, and Japan. The intensified precipitation is attributed to the combined effect of the thermodynamic and dynamic components. The former stems from the enriched low-level moisture, which peaks in continental East Asia in July and August, under global warming. The dynamic effect is due to the enhanced upward motion, associated with the enhanced southerlies throughout the troposphere over midlatitude East Asia. The southerlies also act to intensify the low-level monsoonal circulation, strengthening moisture transport from the tropical ocean to the midlatitudes. In addition to the mean-state changes, the precipitation interannual variability in this region also intensifies, partly due to the enhanced low-level moisture and partly associated with enhanced large-scale circulation anomalies, such as the northwestern Pacific anticyclone. The enhanced background precipitation, along with the intensified interannual variability, may lead to more rainy summers in a warmer climate, with instances where historically extreme precipitation events become more frequent, posing challenges for water resource management and agriculture in the region.

Rhenium–Os isotopic systematics of late Cenozoic intraplate basaltic rocks from Korea: Implications for recycled slab materials in their mantle source

We present, for the first time, comprehensive Re-Os isotopic data for 23 late Cenozoic intraplate basaltic rocks from seven locations (Mount Baekdu, Jeongok, Baengnyeong Island, Ganseong, Ullueng Island, Dok Island, and Jeju Island) on the Korean Peninsula. The Re-Os isotopic system serves as an important tracer of processes such as the reworking of old continental lithosphere or the deep crustal recycling. We use these data to investigate the role of the lithospheric mantle, which is currently debated as a source of the basaltic rocks, and to constrain the source lithology. The initial 187Os/188Os ratios of the Korean basalts range from 0.1321 to 0.6455, with γOs values of 4.0–408.3. The γOs values do not show a simple correlation with Sr-Nd-Hf-Pb isotope compositions. There are no significant correlations between MgO contents and 187Os/188Os ratios or Os contents and 187Os/188Os ratios, which demonstrate that crustal assimilation did not produce the supra-chondritic Os isotopic compositions. The γOs values of the Korean basalts are much higher than previously published γOs of spinel peridotite xenoliths (−9.1 to +1.2) hosted in the basalts, indicating the subcontinental lithospheric mantle was not the main source of the basaltic magmatism. The combination of the Os and Sr-Nd-Hf-Pb isotopic compositions suggests that recycled oceanic crust (potentially Pacific oceanic lithosphere), along with pelagic sediments, which possibly reside in the mantle transition zone, is the enriched component with the supra-chondritic Os isotopic composition in the mantle source of the Korean basalts.

Mimogonellus Fagel and Thoracophorus Motschulsky (Coleoptera: Staphylinidae: Osoriinae) new to Korea

Mimogonellus japonicus (Naomi) and Thoracophorus (Thoracophorus) certatus Sharp are identified for the first time in the Korean peninsula. The genera Mimogonellus Fagel and Thoracophorus Motschulsky are also new records to the Korean fauna. Diagnoses and illustrations of the habitus and diagnostic characters of these two species are provided to facilitate identification.

Molecular phylogeny of Trictenotomidae (Coleoptera: Tenebrionoidea): insights into species validation and biogeography of genus Autocrates

Abstract Trictenotomidae, one of the most charismatic and enigmatic groups of beetles, known for their large size and distinctive mandibles, is widely distributed throughout tropical and subtropical Asia. New species are continually being discovered, and the known range of the group has been expanded considerably by the discovery of Autocrates maqueti Drumont in the Korean Peninsula, ~2,000 km from its previously known distribution in the Chinese mainland highlands. A comprehensively sampled multigene phylogenetic tree of Trictenotomidae, including all six species of Autocrates and five species of Trictenotoma, was reconstructed using multigene data. Using the resulting phylogeny, we performed divergence time estimation, biogeographical assessments, and molecular species delimitation. All six known species of the genus Autocrates were found to be valid in all four molecular species delimitation scenarios, indicating the need for further taxonomic research on these poorly understood taxa. The A. maqueti population in South Korea forms a genetically distinct clade in all genetic analyses, suggesting that it is a natural distribution rather than a result of anthropogenically driven spread. The Korean A. maqueti population is likely to have been isolated since ~1.8 Mya, when the Yellow Sea was still a landmass, highlighting the need for targeted conservation measures in South Korea.

Three Falagriini species (Coleoptera: Staphylinidae: Aleocharinae) new to Korea

Cordalia occipitalis Pace, Myrmecocephalus concinnus (Erichson), and Myrmecocephalus zhejiangensis (Pace) are identified for the first time in the Korean peninsula. The genus Cordalia Jacobs is also new record to the Korean fauna. An updated key is given for the separation of the known species of Korean Falagriini. Redescriptions and illustrations of habitus and diagnostic characters are provided to facilitate identification.

A record of the northernmost location of Otus elegans in the Pacific area

This individual of Otus elgans was rescued on Udo Island located in the east of Jeju Island, the southernmost part of the Korean Peninsula, on January 4, 2007. It was found at 3° 32″ N, 2° 58′ E, which is the northernmost record among the habitats of Otus elegans. After that, we took photographs of its shape, recorded its calls, and analyzed them. While analyzing we confirmed that it is an unrecorded species in Korea. We classified the chick calls based on structural similarity on spectrograms (view range: 0–7.5 kHz; window length: 1 second). We measured it and the results are; weight: 86.7 g, total length: 210 mm, wing length: 170 mm, tail length: 68.0 mm, and Tarsus length: 25.13 mm. In addition, its vocalizations are structurally diverse: duration, ∼10 ms to 1.5 s; peak frequency (adults), <900 to >3000 Hz. Currently, it was found not only on Nansei Shoto, Minami-daito-jima, and Okino Islands in Japan but also on the Batanes Islands in eastern China and the Babuyan Islands. Moreover, assumed that it inhabits Okinoshima, lying beyond the known northern limit of distribution. Therefore, this study record demonstrates the attempt of O. elegans to move north even to Udo Island from the previous habitats.

TPTNet: A Data‐Driven Temperature Prediction Model Based on Turbulent Potential Temperature

AbstractA data‐driven model for predicting the surface temperature using neural networks was proposed to alleviate the computational burden of numerical weather prediction (NWP). Our model, named TPTNet uses only 2 m temperature measured at the weather stations of the South Korean Peninsula as input to predict the local temperature at finite forecast hours. The turbulent fluctuation component of the temperature was extracted from the station measurements by separating the climatology component accounting for the yearly and daily variations. The effect of station altitude was then compensated by introducing a potential temperature. The resulting turbulent potential temperature (TPT) data at irregularly distributed stations were used as input for predicting the TPT at forecast hours through three trained networks based on convolutional neural network, Swin Transformer, and a graph neural network. By comparing the prediction performance of our network with that of persistence and NWP, we found that our model can make predictions comparable to NWP for up to 12 hr.

Current Situation of Chinese Academia’s Study on the Korean Peninsula -Focusing on the Analysis of Political, Diplomatic, and Security Areas-

Current Situation of Chinese Academia’s Study on the Korean Peninsula -Focusing on the Analysis of Political, Diplomatic, and Security Areas-

Silk-ma Mixed Woven Textiles in East Asian History

Mixed woven textile (交織物) is a textile woven with yarns of two or more different fibres, in which each yarn contains only one type of fibre. Silk and ma (麻, a Chinese character used to name mainly bast and leaf fibres) are two kinds of the earliest fibre materials used in East Asia. They were opposite in properties, usage and social status in ancient East Asian society where cultures shared the same origin and social hierarchy was extremely rigid under the influence of Confucianism. However, they were woven into silk-ma mixed woven textiles as early as 2355&amp;plusmn;45 BP in China, as attested by the discovery of archaeological fabric fragments woven with silk and ramie-hemp threads. Archaeological artefacts and ancient documents of silk-ma mixed woven textiles are seldom discovered or recognized, most probably not because of their rare existence in history but because of the lack of precise identification. This paper will share historical evidence of silk-ma mixed woven textiles in the Chinese mainland, the Korean peninsula and the Japanese archipelago, summarize their features and reveal the possible reasons for their elusive presence.

Prospects for Military Conflict on the Taiwan Strait and the Korean Peninsula and Allied Responses

Prospects for Military Conflict on the Taiwan Strait and the Korean Peninsula and Allied Responses

언어 접촉(Language Contact)의 관점에서 본 중국 조선어의 변이 양상

This paper aims to empirically demonstrate the variation patterns observed in Chinese Korean and rationally explain them from the perspective of language contact. Over a long period and for various reasons, the ethnic Koreans who migrated from the Korean Peninsula to China have been influenced by the Han Chinese, the majority ethnic group in China, in numerous aspects, including economy, society, culture, and language, due to the policies of the Chinese government. In the multi-ethnic and multilingual society of China, language contact is a common phenomenon. Consequently, Chinese Korean inevitably exhibits elements of the Chinese language in addition to its original Korean linguistic features. Previous research has primarily focused on the diachronic perspective, addressing the characteristics of Korean vocabulary altered under the influence of Chinese. This paper, however, aims to directly observe the variation patterns resulting from language contact with Chinese from a synchronic perspective. For this purpose, Korean compositions written by adolescents in Korean ethnic communities were collected and comprehensively examined. The analysis revealed a significant presence of hybrid words combining Korean derivational suffixes or endings with Chinese morphemes, despite the typological and genealogical differences between Korean and Chinese. Additionally, certain sentence structures showed the influence of Chinese. Based on these findings, it was concluded that the intensity of contact between Korean and Chinese corresponds to level three according to Thomason (2001).

Geopolitical Kingmakers: South Korea and the Philippines as Linchpins amid the China–US Competition

Abstract South Korea and the Philippines hold pivotal geopolitical positions amidst escalating tensions between the USA and China. Both Seoul and Manila find themselves ensnared in the expanding rivalry between these great powers, subjecting them to numerous strategic challenges amid the prevailing regional status quo of instability. Despite their efforts to maintain a delicate balance, often characterized as hedging behavior, the space available for such maneuvering is diminishing, compelling them toward perilous geopolitical alignments. Therefore, this paper seeks to address the following questions: How does the shrinking space to hedge influence the alignment strategies of South Korea and the Philippines? How do their alignment choices impact the geopolitical dynamics of the China–US strategic competition? It argues that as this space contracts, they possess the capability to significantly influence the regional balance of power through their alignment, which we frame as the kingmaker’s role and the power of the weak paradox. Seoul, navigating the complex dynamics of the Korean Peninsula, must carefully weigh its commitments to both Washington and Beijing, particularly in light of ongoing developments with North Korea. Meanwhile, Manila, in the aftermath of the Duterte administration’s alignment oscillations, has sought to establish a clearer strategic direction largely influenced by tensions in the South China Sea. Both are now increasingly tacking hard toward Washington for security assurances and have acknowledged economic security anxieties concerning their links with Beijing. Furthermore, they are placing greater emphasis on upholding the rules-based international order amid growing global uncertainties.

Enhanced water level monitoring for small and complex inland water bodies using multi-satellite remote sensing

Water level monitoring in lakes and reservoirs is essential for effective water resource management, especially in remote areas where traditional ground sensors are costly and difficult to maintain. Remote sensing offers an alternative, but improving the quality, resolution, and accuracy of satellite data remains crucial. This paper introduces MoRLa (Measurement of Reservoir Level from Altimetry), a data filtering procedure designed to enhance satellite altimetry retrievals. MoRLa increases the acceptance of satellite observations and improves the quality of water level estimates by using physical characteristics of water bodies to exclude non-conforming measurements. Unlike previous studies with static masks, MoRLa employs a dynamic filter adaptable to actual water levels at specific times. Tested on reservoirs in the Korean Peninsula, including the Hwang-Gang dam, MoRLa shows significant improvements in water level measurements using Cryosat-2, ICESat-2, and Sentinel-3A and B satellites.

Interpretation and implications of high-resolution hydroclimatic records of the past 7,000 years based on Gaho paleolake sediments in South Korea

In this study, we investigated the past hydroclimate and its controlling factors over East Asia by reconstructing hydroclimate variability during the middle-to-late Holocene using rainfall-driven sedimentary features in the Gaho paleolake, Hapcheon County on the southern Korean Peninsula. Based on radiocarbon dates, median grain sizes, and elemental ratios of strontium (Sr), titanium (Ti), and zirconium (Zr) measured by high-resolution X-ray fluorescence core scanning, we tested potential indicators of past heavy rainfall. During the past 7000 years, temporal changes in median grain size and elemental ratios (Sr/Ti and Zr/Ti) were found to be similar to those in the Asian monsoonal precipitation index and sea surface temperature (SST) in the western North Pacific region, suggesting that periods with increased elemental ratios may have been influenced by intensified regional rainfall events and higher SSTs. During the past 2000 years, time series of Sr/Ti and Zr/Ti ratios in the paleolake sediments appeared to covary with a megadrought period (AD 1593–1698; 357-252 cal BP), flooding events in the 1500s, and the collapse of ancient nations in Korea and other parts of East Asia. This similarity between sedimentary records and historical events suggests considerable potential for the dating of elemental ratios in lake sediments as high-resolution analogs of past hydrological events to support historical records.

State-Sponsored Maitreya Cult and the Shouluo Biqiu Jing A Case of a Transmission of a Heterodoxy to Korea

In this paper, the author analyses the apocryphal text Shouluo biqiu jing, centred around the saviour bodhisattva Yueguang Tongzi (Candraprabhākumāra in Sanskrit). It is possible that this text was written in Silla, with some connection with its royalty and the hwarang group. This paper confronts this hypothesis with other ones that connect it to some Sui-Tang millenarian movements. Chosen methodology is the historical and philological analysis. The conclusion is that the text was likely written in China, bu it possibly circulated in Korean Peninsula. The text is probably the result of composition and manipulation.

Evidence for large Holocene earthquakes along the Yangsan fault in the SE Korean Peninsula revealed in three-dimensional paleoseismic trenches

Evidence for large Holocene earthquakes along the Yangsan fault in the SE Korean Peninsula revealed in three-dimensional paleoseismic trenches