South Korean Peninsula Research Articles

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.

Predicting the spatio-temporal distribution of the invasive alien plant Andropogon virginicus, in the South Korean peninsula considering long-distance dispersal capacities.

The spread of invasive alien species is a major threat to biodiversity. Estimating the long-distance dispersal capacity of invasive alien plants is vital for understanding their population dynamics and community composition. We predicted the spatial-temporal distribution of the alien plant Andropogon virginicus, in the Korean peninsula under climate change scenario using Random Forest (RF) and Cellular Automaton (CA) methods. Land use, barriers to dispersal, long-distance dispersal frequency, and maximum long-distance dispersal range were considered in our analysis. Our results showed that, among the five selected environmental variables, annual mean temperature and Human Foot-Printing (HFP) were positively associated with the occurrence probability of A. virginicus. This suggests that A. virginicus is likely to spread to the disturbed northern part of the Korean Peninsula due to climate change and habitat preference. When comparing modeling results for dispersal to field survey data, the modeling raster sets drawn from the long-distance dispersal frequency of 0.05 and maximum long-distance dispersal distance of 30 km y-1 had the most similar spatial expansion among the six long-distance dispersal parameter sets. The dispersal directions were associated with the landscape. Specifically, seeds dispersed by wind (anemochorous seeds) could propagate into open landscapes more easily than in forests. Regarding A. virginicus management, this grass can quickly invade bare ground with their wind-dispersed seeds, therefore habitat destruction, such as excessive logging and weeding, should be restrained.

Seasonal and regional variations of atmospheric ammonia across the South Korean Peninsula

This study aimed to identify the factors causing NH3 emissions in the South Korean Peninsula and West Sea region. To analyze the trends of NH3 and other air pollutants, such as NOx, CO, and NR-PM1, we collected samples from six supersites across the peninsula, a roadside in Seoul, and the West Sea over different sampling periods, ranging from 1 month to 1 year. The highest NH3 concentrations were found at rural areas, ascribed to agricultural activities, particularly NH4NO3 decomposition at high summer temperatures. Areas with low population densities recorded the lowest NH3 concentrations, attributed to the lack of anthropogenic activities. A roadside field experiment confirmed the close link between ambient NH3 and vehicle emissions in urban regions by showing a strong correlation between CO and NOx concentrations and that of NH3. Moreover, we examined oceanic emissions near the eastern coast of South Korea in the West Sea. Long-range transportation studies confirmed that most of the pollutants (NH3, CO, and PM1) were transported by wind from the northeastern region of China. A maritime origin study showed that oceanic emissions and NH4NO3 decomposition in the atmosphere owing to high temperatures were the causing NH3 pollution. These findings provided valuable insights into the emission sources of NH3 in primary air pollutants in South Korea, highlighting the contributions of land-based and oceanic sources. Our study can help inform policymakers and stakeholders for developing effective regional air pollution control strategies.

Understanding Impact of the Volcanic Eruption of Nishinoshima, Japan on Air Quality in the South Korean Peninsula

Understanding Impact of the Volcanic Eruption of Nishinoshima, Japan on Air Quality in the South Korean Peninsula

Progress on the nephrite sources of jade artifacts in ancient China from the perspective of isotopes

The use of isotopes is crucial for understanding the origin of jade/nephrite. This article first contrasts recent studies on the radioisotopes and stable isotopes of contemporary nephrite deposits in China, Baikal region, and South Korean Peninsula. It then reviews the isotopic analysis of the sources of nephrite artifacts in ancient China, highlighting the concentration of contemporary nephrite deposits with distinct isotopic fingerprints in three significant geographic areas, Northeast Asia, the Yellow River Basin, and South China Region. That is, with regard to Northeast Asia, S‐type and D‐type nephrite in Baikal region, and D‐type nephrite in Chuncheon of South Korea as well as Xiuyan and Kuandian of Liaoning Province can be distinguished well by the radioisotope mineralization age and hydrogen and oxygen isotopic values; with regard to the Upper Yellow River, the isotope method of hydrogen, oxygen and silicon isotopic values has the potential to distinguish the D-type and S-type nephrite in Xinjiang Province and Qinghai Province, while cannot distinguish the D-type nephrite from Hetian, Xinjiang Province and Lintao/Maxianshan, Gansu Province; with regard to South China, the isotope method of the radioisotope mineralization age and hydrogen and oxygen isotopic values has the potential to distinguish D-type nephrite from Fugong in Yunnan Province, Dahua in Guangxi Province and Luodian in Guizhou Province, and S-type nephrite in Hualian, Chinese Taiwan. It is recommended that isotopic database of jade materials from more deposits and excavated jadewares must be established, in order to answer significant archaeological questions regarding the role of jade material utilization in the origin, formation and development of Chinese jade culture and Chinese civilization.

Clustering for Regional Time Trend in the Nonstationary Extreme Distribution

Since the estimation of tail properties requires a stationarity of observations, it is necessary to develop a de-trending method not dependent on underlying distributions for nonstationary hydrological processes. Moreover, de-trending has been independently applied to hydrological processes, even though the processes are observed in geometrically adjacent sites. This paper presents a distribution-free de-trending method for nonstationary hydrological processes. Our method also provides clustered regional trends obtained by sparse regularization in a general distribution. It aggregates the parameter estimation and clustering within a unified framework. In the simulation study, our proposed method has superiority over other compared methods with respect to MSE and variance of coefficients. In real data analysis, the clustered trends of the annual maximum precipitation in the South Korean peninsula are reported, and the patterns of the estimated trends are visualized.

Geodetic Analysis inside the South Korean Peninsula and Impact of the 2011 Tohoku–Oki (TO) Earthquake

AbstractThe most powerful Tohoku–Oki (TO) earthquake that occurred in Japan on 11 March 2011 affected Japan as well as South Korea. In the current study, we investigated contemporary geodetic deformation inside South Korea before and after the TO earthquake using Global Navigation Satellite System (GNSS) measurements from 01 January 2008 to 31 December 2017. Measured velocities of GNSS sites are modeled by Auto‐regressive moving average (ARMA) method to analyze the long‐term GNSS time‐series variation and to investigate the secular tectonic crustal deformation. We found that the maximum co‐seismic displacements during the TO earthquake reached up to 36.82 ± 0.21 mm in the east and 5.90 ± 0.08 mm in the north directions. The geometric model of the co‐seismic thrust surface was characterized by a rectangular plane with a dip of 12.0° and strike 200°. The thrust is situated at 25 km hypocenter depth, with an area roughly ∼470 km long and ∼120 km wide. The seismicity pattern after the earthquake indicated that the compressional strain started to be replaced by the extensional strain during the post TO earthquake period from 2011 to 2014. Further, the strain became predominantly extensional during the period 2015 to 2017, revealing an effective rotational change that occurred inside the Korean Peninsula.

Validation of analytical methods for organochlorine pesticide detection in shellfish and cephalopods by GC-MS/MS.

This study validated the analysis of organochlorine pesticides (OCPs) in shellfish and cephalopods using a gas chromatograph equipped with a mass spectrometry (GC-MS/MS), and monitored residual pesticide levels. The QuEChERS method was used to analyze OCPs and was validated by checking the linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, and precision. Octopus minor and Venerupis philippinarum, were purchased from four cities in the South Korean peninsula. The LOD values were 0.10-0.80ng/g in shellfish and 0.21-0.77ng/g in cephalopods, while the LOQ values were 0.31-2.41ng/g in shellfish and 0.63-2.33ng/g in cephalopods. Accuracy ranged from 83.5 to 117.4% and 79.8 to 118.4%, and precision ranged from 0.3 to 27.5% and 1.2 to 27.9%, in shellfish and cephalopods, respectively, conforming to the Codex Alimentarius Commission guidelines. Although residual OCP levels were below detection limits, the QuEChERS method may be effective for analyzing the OCPs in shellfish and cephalopods.

(Re)mapping the Yanggongju and the Camptown in Shin Sang-ok's Hellflower

The Korean War (1950–53) changed the material and affective landscape of the Korean peninsula and ushered in a new era ruled by a military dictatorship dependent on US military power. With bases dotting the South Korean peninsula, former agricultural villages became camptowns that catered to the needs of American soldiers. This article focuses on the South Korean melodrama Chiokhwa (Hellflower, 1958), directed by Shin Sang-ok, which narrates a love triangle between two brothers and Sonya, a camptown prostitute or yanggongju. It examines the role of the postwar environment in constructing the spaces of the subject. Using the yanggongju figure as a technology of postwar memory, this work reevaluates the ecology of ruination left in the wake of the Korean War—as portrayed through Sonya, scenes of the city, the camptown, the base, and the surrounding fields and marshes—to explore the sense of loss and displacement of this period.

Plant species colonization in newly created road habitats of South Korea: Insights for more effective restoration

Despite the advances in restoration methods for newly created road habitats such as roadcuts and embankments, implementation in different parts of the world is limited by high cost and lack of knowledge of naturally formed plant communities. However, a cheaper alternative is to relay in natural successional process in sites under optimal conditions. Thus, the first steps should focus on identifying plant species that colonize roadways and road habitats as well as optimal colonization sites. Our study aimed to describe species composition, exotic species presence, and diversity among four roadways (Jeongok-Youngjung, JG; Seolma-Gueup, SM; Singal, SG; and Samga-Daechon, DC) and three habitat types (embankments, plain areas, and roadcuts) in South Korean peninsula. The effect of some environmental factors on plant composition was also examined (soil type, soil slope, and surrounding landscape). Our results showed that established plant species composition was influenced by the interaction between roadways and habitats types, which was also the main interaction affecting plant richness and evenness. Surprisingly, environmental variables had no effect on plant species composition, with a residual amount of explained variation. A total of 48 plant species were described as indicator of different roadways and habitat types, and 50% of them were invasive or cultivated species. It appeared that different regional-dependent processes, such as northern vs. southern roadways, interact with local process in new-road habitats, producing complex patterns of plant species colonization and composition. Thus, ecological restoration solutions should be targeted at site-specific needs (local) while taking into consideration the differences between northern and southern roadways (regional). Here, regional-pool and local-constraints interaction controls plant composition and diversity during road construction in South Korea. Finally, new restoration actions should be based on plant species that have been established spontaneously in these degraded areas.

Numerical simulation of atmospheric CO2 concentration and flux over the Korean Peninsula using WRF-VPRM model during Korus-AQ 2016 campaign.

We conducted regional scale CO2 simulations using the Weather Research and Forecasting model (WRF) coupled with the Vegetation Photosynthesis and Respiration Model (VPRM). We contrasted simulated concentrations with column, ground and aircraft observations during the Korea-United States Air Quality (KORUS-AQ) 2016 field campaign. Overall, WRF-VPRM slightly underestimates CO2 concentrations at ground and column monitoring sites, but it significantly underestimates at an inland tower measurement site, especially within the stable (nocturnal) boundary layer in nighttime. The model successfully captures the airborne vertical profiles but showed a large offset within the planetary boundary layer (PBL) in the areas surrounding Seoul and around the Taeahn point source emissions in the west coastal area of the Korean Peninsula. A case study flight intended to capture Chinese influence observed no clear signals of long-range transport of CO2, due mainly to the much larger magnitude of background CO2 concentrations. The calculated Net Ecosystem Exchange (NEE) with flux measurements at a tower site in the South Korean Peninsula has also been evaluated comparing with CO2 flux measurements at a flux tower site, resulting in the underestimation by less than a factor of 1.

Benefit of China’s reduction in nitrogen oxides emission to natural ecosystems in East Asia with respect to critical load exceedance

The emission of nitrogen oxides (NOx) in China decreased by 15% from 2010 to 2015 (without a significant decrease in NH3 emission), resulting in the decline of nitrogen (N) deposition in East Asia. Empirical N critical load exceedance was used to assess the benefit of the NOx emission reduction in China to natural ecosystems in East Asia. Empirical N critical loads for major forest and grassland types in East Asia were assigned based on field manipulation experiments for N effects. The critical load map based on the minimum of the critical load range of each vegetation type showed that empirical critical loads were generally lower in the Tibetan Plateau and some parts of northeastern China (≤5 kgN·ha−1·a−1), and higher in northern and southern China (≥20 kgN·ha−1·a−1). Empirical critical loads were also low in some parts of central and northern Japan (≤5 kgN·ha−1·a−1) and the south Korean Peninsula (5–10 kgN·ha−1·a−1). As a benefit of NOx emission reduction in China, N deposition in East Asia decreased significantly from 2010 to 2015. The total area and total amount of critical load exceedance in East Asia declined 4.6% and 14.3% respectively, suggesting great benefits to natural ecosystems.

Investigation of factors controlling PM2.5 variability across the South Korean Peninsula during KORUS-AQ.

The Korea – United States Air Quality Study (May – June 2016) deployed instrumented aircraft and ground-based measurements to elucidate causes of poor air quality related to high ozone and aerosol concentrations in South Korea. This work synthesizes data pertaining to aerosols (specifically, particulate matter with aerodynamic diameters <2.5 micrometers, PM2.5) and conditions leading to violations of South Korean air quality standards (24-hr mean PM2.5 < 35 μg m−3). PM2.5 variability from AirKorea monitors across South Korea is evaluated. Detailed data from the Seoul vicinity are used to interpret factors that contribute to elevated PM2.5. The interplay between meteorology and surface aerosols, contrasting synoptic-scale behavior vs. local influences, is presented. Transboundary transport from upwind sources, vertical mixing and containment of aerosols, and local production of secondary aerosols are discussed. Two meteorological periods are probed for drivers of elevated PM2.5. Clear, dry conditions, with limited transport (Stagnant period), promoted photochemical production of secondary organic aerosol from locally emitted precursors. Cloudy humid conditions fostered rapid heterogeneous secondary inorganic aerosol production from local and transported emissions (Transport/Haze period), likely driven by a positive feedback mechanism where water uptake by aerosols increased gas-to-particle partitioning that increased water uptake. Further, clouds reduced solar insolation, suppressing mixing, exacerbating PM2.5 accumulation in a shallow boundary layer. The combination of factors contributing to enhanced PM2.5 is challenging to model, complicating quantification of contributions to PM2.5 from local versus upwind precursors and production. We recommend co-locating additional continuous measurements at a few AirKorea sites across South Korea to help resolve this and other outstanding questions: carbon monoxide/carbon dioxide (transboundary transport tracer), boundary layer height (surface PM2.5 mixing depth), and aerosol composition with aerosol liquid water (meteorologically-dependent secondary production). These data would aid future research to refine emissions targets to further improve South Korean PM2.5 air quality.

‘일통삼한 의식’과 표상으로서의 ‘삼한’

Recently, three opinions have been in confrontation over the time of the formation of the ‘Perception of Iltong-Samhan (Unification Three Hans)’. First, the theory that the perception of Iltong-Samin was formed with ‘the war of unification of the three Kingdoms’ in the 7th century as a momentum; second, the theory that although the relevant perception appeared in the 7th century, it was a false consciousness made up irrelevant to the reality; and third, the theory that the perception of ‘Iltong-Samhan’ not only was a false consciousness but also the time of occurrence of that was the 9th century, relevant to the late Silla dynasty. Of them, the second view and the third view are based on the perception that the so-called ‘war of unification of the three Kingdoms’ is not compatible with the actual historical fact and that the relevant war was just Silla’s war of the integration of Baekje. However, when the contents of various materials of the time, the fact that the ‘perception of Iltong-Samhan’ appeared in the 7th century is verified. The people of Shilla had a perception that they unified ‘the Land of Samhan,’ including Goguryeo as well as Baekje spatially. The term ‘Samhan’ used at the time was a concept of a historical and geographic space covering the central south Korean peninsula including the Pyongyang region. According to this, the slogan, ‘Samhan Iltong’ was a concept that had logical completeness itself unlike the ‘perception of unification of the Three Kingdoms’ implying territorial imperfection.

Taxonomic Revision of the Lichen Genera Pertusaria, Varicellaria, and Variolaria (Pertusariales, Ascomycota) in South Korea

The crustose lichen genus Pertusaria comprises over ca. 800 species worldwide. In total, 20 Pertusaria species were localized to the Mt. Sorak and Jeju-do in Korea. To date, information regarding the distribution of Pertusaria species in the South Korean peninsula is scarce. In this study, we collected Pertusaria species across South Korea and identified them based on morphological, chemical, and molecular characteristics. Of the 387 samples collected, we identified 24 taxa and 1 variety, of which 17 were previously recorded, and 6 taxa were newly found in South Korea (P. leioplaca, P. leucosora var. violascens, P. texana, P. thiospoda, P. thwaitesii, and P. xanthodes), 2 known species were transferred to Varicellaria (Varicellaria lactea and V. velata), one species was transferred to Variolaria as a new record (Variolaria multipunctoides) and one was a new species (P. jogyeensis J. S. Park & J.-S. Hur, sp. nov.). Characteristics of the newly discovered species, P. jogyeensis, are as follows: smooth to bumpy thallus, scattered to crowded poriform apothecia, blackish ostioles, definitely sunken, thin yellowish green rims around ostioles, 8-spored ascus, and the presence of perlatolic acid and thiophaninic acid (chlorinated xanthone). Phylogenetic studies on P. jogyeensis based on the mitochondrial small subunit sequence revealed proximity to P. flavicans and P. texana, and supported its classification as a new species within the genus Pertusaria. Additionally, we describe the chemical composition and morphology of all listed species in detail and provide an artificial key for identification.

Selection of representative GCM scenarios preserving uncertainties

Abstract Climate change studies usually include the use of many projections, and selecting an essential number of projections is very important, because using all Global Climate Model (GCM) scenarios is impossible in practice. Furthermore, the climate change impact assessment is often sensitive to the choice of GCM scenarios. This study suggests that selecting the best-performing scenarios based on a historical period should be avoided in nonstationary cases like climate change, and then proposes a new approach that can preserve the uncertainty, that all scenarios contain. The new approach groups all GCM scenarios into several clusters, and then selects a single representative scenario among member scenarios of each cluster, based on their skill scores. The proposed approach is termed ‘selecting the principal scenarios’, and applied to select five principal GCM scenarios for the South Korean Peninsula, among 17 GCM scenarios of the 20C3M emission scenario. The uncertainty preservation is measured with the maximum entropy theory. The case study presents that the principal scenarios preserve the full range of total uncertainty, compared to less than 65% for the best scenarios confirming that preserving uncertainty with the principal scenarios is more adequate, than selecting the best-performed scenarios, in climate change studies.

Serological and molecular prevalence of canine vector-borne diseases (CVBDs) in Korea

BackgroundPrevious surveys in dogs from Korea indicated that dogs are exposed to a variety of vector- borne pathogens, but perception for a nation-wide canine vector-borne disease (CVBD) occurrence has been missing. We report here results of both serological and molecular prevalence studies for major CVBDs of dogs from all over the South Korean Peninsula except for Jeju Island.ResultsSerological survey of 532 outdoor dogs revealed the highest prevalence for Dirofilaria immitis (25.2%), followed by Anaplasma phagocytophilum (15.6%), Ehrlichia canis (4.7%) whereas Borrelia burgdorferi showed the lowest prevalence (1.1%). The number of serologically positive dogs for any of the four pathogens was 216 (40.6%). Concurrent real-time PCR assay of 440 dogs in the study indicated that DNA of “Candidatus M. haematoparvum”, Mycoplasma haemocanis, Babesia gibsoni, A. phagocytophilum, and Hepatozoon canis was identified in 190 (43.2%), 168 (38.2%), 23 (5.2%), 10 (2.3%) and 1 (0.2%) dogs, respectively. DNA of Bartonella spp., Ehrlichia spp., Leishmania spp., Rickettsia spp. and Neorickettsia risticii was not identified. Analysis of questionnaires collected from owners of 440 dogs showed that the number of dogs with heartworm preventive medication was 348 (79.1%) among which dogs still positive to D. immitis infection were 60 (17.2%), probably due to the mean months of heartworm preventive medication being only 6.5. The high prevalence rates of both “Ca. M. haematoparvum” and Mycoplasma haemocanis in dogs from Korea indicate that these organisms may be transmitted by vectors other than Rhipicephalus sanguineus because this tick species has rarely been found in Korea. This is the first nationwide survey for canine haemotropic mycoplasma infections in Korea.ConclusionsThis study showed that the risk of exposure to major vector-borne diseases in dogs is quite high throughout all areas of South Korean Peninsula. Since achieving full elimination of many pathogens causing CVBDs from infected animals is often impossible even when they are clinically cured, dogs once exposed to CVBDs can remain as lifetime reservoirs of disease for both other animals and humans in the close vicinity, and should therefore be treated with preventative medications to minimise the risk of pathogen transmission by the competent vectors.

Genetic differentiation of the Korean striped field mouse, Apodemus agrarius (Muridae, Rodentia), based on microsatellite polymorphism

Abstract The striped field mouse (Apodemus agrarius) is one of the most common mammals in Korea, however, limited research has focused on the population structure and biogeography of this mouse throughout Korea. In addition, the taxonomic status of the species remains unresolved. The objectives of our study were to address the inadequacies in understanding the population structure, biogeography, and taxonomic status of A. agrarius. We collected 160 samples from 13 localities throughout the South Korean Peninsula, two nearby islands and two remote islands. We used five microsatellite loci and estimated genetic diversity measures and populations divergence estimates (i.e. F ST and R ST) to address the objectives. Except for populations on the two remote islands, Jeju and Heuksan, the populations on the peninsula and nearby islands indicated low F ST and R ST values. The population structure based on microsatellite loci supported only one subspecies opposing three subspecies reported previously on the Korean Peninsula and nearby islands. However, populations on Jeju Island and Heuksan Island showed subspecific differences from each other and the populations on the Korean Peninsula and nearby islands. The information reported on the population genetics of the striped field mouse in Korea will allow resolving the taxonomy and biogeography of this species.

Bayesian analysis to detect abrupt changes in extreme hydrological processes

Summary In this study, we develop a new method for a Bayesian change point analysis. The proposed method is easy to implement and can be extended to a wide class of distributions. Using a generalized extreme-value distribution, we investigate the annual maximum of precipitations observed at stations in the South Korean Peninsula, and find significant changes in the considered sites. We evaluate the hydrological risk in predictions using the estimated return levels. In addition, we explain that the misspecification of the probability model can lead to a bias in the number of change points and using a simple example, show that this problem is difficult to avoid by technical data transformation.

Response of the mid-latitude D-region ionosphere to the total solar eclipse of 22 July 2009 studied using VLF signals in South Korean peninsula

In this paper, we analyze VLF signals received at Busan to study the the D-region changes linked with the solar eclipse event of 22 July 2009 for very short (∼390km) transmitter–receiver great circle path (TRGCP) during local noon time 00:36–03:13UT (09:36–12:13KST). The eclipse crossed south of Busan with a maximum obscuration of ∼84%. Observations clearly show a reduction of ∼6.2dB in the VLF signal strength at the time of maximum solar obscuration (84% at 01:53UT) as compared to those observed on the control days. Estimated values of change in Wait ionospheric parameters: reflection height (h′) in km and inverse scale height parameter (β) in km−1 from Long Wave Propagation Capability (LWPC) model during the maximum eclipse phase as compared to unperturbed ionosphere are 7km and 0.055km−1, respectively. Moreover, the D-region electron density estimated from model computation shows 95% depletion in electron density at the height of ∼71km. The reflection height is found to increase by ∼7km in the D-region during the eclipse as compared to those on the control days, implying a depletion in the Lyman-α flux by a factor of ∼7. The present observations are discussed in the light of current understanding on the solar eclipse induced D-region dynamics.