• Title/Summary/Keyword: North-east Asia

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Evaluation of Climatological Mean Surface Winds over Korean Waters Simulated by CORDEX-EA Regional Climate Models (CORDEX-EA 지역기후모형이 모사한 한반도 주변해 기후평균 표층 바람 평가)

  • Choi, Wonkeun;Shin, Ho-Jeong;Jang, Chan Joo
    • Atmosphere
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    • v.29 no.2
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    • pp.115-129
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    • 2019
  • Surface winds over the ocean influence not only the climate change through air-sea interactions but the coastal erosion through the changes in wave height and direction. Thus, demands on a reliable projection of future changes in surface winds have been increasing in various fields. For the future projections, climate models have been widely used and, as a priori, their simulations of surface wind are required to be evaluated. In this study, we evaluate the climatological mean surface winds over the Korean Waters simulated by five regional climate models participating in Coordinated Regional Climate Downscaling Experiment (CORDEX) for East Asia (EA), an international regional climate model inter-comparison project. Compared with the ERA-interim reanalysis data, the CORDEX-EA models, except for HadGEM3-RA, produce stronger wind both in summer and winter. The HadGEM3-RA underestimates the wind speed and inadequately simulate the spatial distribution especially in summer. This summer wind error appears to be coincident with mean sea-level pressure in the North Pacific. For wind direction, all of the CORDEX-EA models simulate the well-known seasonal reversal of surface wind similar to the ERA-interim. Our results suggest that especially in summer, large-scale atmospheric circulation, downscaled by regional models with spectral nudging, significantly affect the regional surface wind on its pattern and strength.

Case Studies of Mass Concentration Variation in the Central-Southern Korean Peninsula Caused by Synoptic Scale Transport of Dust Storms

  • Kim, Hak-Sung;Cho, Jae-Hee
    • Journal of the Korean earth science society
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    • v.40 no.4
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    • pp.414-427
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    • 2019
  • In East Asia, the long-range transport of dust storms originating from Mongolia and northern China affects airborne dust loadings over downwind areas in the southern Korean Peninsula. Since 1997, dust loading cases caused by dust storms have been observed using the thresholds of total suspended particles (TSP, ${\geq}250{\mu}g\;m^{-3}\;hr^{-1}$) and particulate matter less than $10{\mu}g$ ($PM_{10}$, ${\geq}190{\mu}g\;m^{-3}\;hr^{-1}$) in the central-southern Korean Peninsula. There were two dust loading cases that exceeded these thresholds in 2016 and three in 2017, which reflects the downward trend of the last twenty-one years in the central-southern Korean Peninsula. Furthermore, five other dust loading cases with mass concentrations lower than the thresholds were observed from 2016 to 2017. In the moderate dust loading cases exceeding the thresholds, a descending motion of cut-off lows below $45^{\circ}N$ and a southward trough at 500 hPa gpm isopleths intensified at the western ridge, and largely extended the surface high-pressure system over southeast China. Airborne dust loadings following pronounced north-westerlies in the forward side of the high-pressure system were transported to the surface of the central-southern Korean Peninsula. However, in slight dust loading cases lower than the thresholds, the restricted descending motion of cut-off lows over $45^{\circ}N$ and the southwestward trough at 500 hPa gpm isopleths intensified the zonal flow over the Korean Peninsula. Surface high- and low-pressure systems moved eastward from the source compared to moderate dust loading cases. Due to the zonal movement of dust storms traversing eastern China, slight dust loading cases were observed with relatively higher ratios of $PM_{2.5}/TSP$ and carbon monoxide (CO) in the central-southern Korean Peninsula.

Interdecadal Changes in the Number of Days on Which Temperatures are not Higher Than -5℃ in Winter in Seoul (서울에서 겨울철 기온이 -5℃ 이하인 날 수의 십년간 변동 특성)

  • Choi, Jae-Won;Cha, Yumi;Kim, Jeoung-Yun;Park, Cheol-Hong
    • Journal of Climate Change Research
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    • v.7 no.1
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    • pp.49-57
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    • 2016
  • In the present study, the time series of the number of days on which temperatures were not higher than $-5^{\circ}C$ in winter in Seoul was analyzed. The results showed a decreasing tendency until recently. Statistical change-point analysis was conducted to examine whether climate regime shifts existed in this time series. According to the results, the number of days on which temperatures were not higher than $-5^{\circ}C$ in winter in Seoul drastically decreased since 1988. Therefore, to find out the reason for the recent decrease in the number of days, differences between the means of large-scale environments in winder during 1988~2010 and those during 1974~1987 were analyzed. In all layers of the troposphere, anomalous anticyclones developed in regions around the Korean Peninsula and thus the Korean Peninsula was affected by westerlies or south-westerlies. This was associated with the recent a little further northward development of western North Pacific subtropical high. Therefore, environments good for warm and humid air to flow into the Korean Peninsula were formed. To examine whether relatively warm and humid air actually flowed into the Korean Peninsula recently, temperatures and specific humidity in all layers in the troposphere were analyzed and according to the results the Korean Peninsula showed warm and humid anomalies. In the analyses of sensible heat net flux and maximum temperatures at a height of 2 m that can be felt by humans, the East Asia Continent including the Korean Peninsula showed positive anomalies.

How to develop strategies to use insects as animal feed: digestibility, functionality, safety, and regulation

  • Jae-Hoon, Lee;Tae-Kyung, Kim;Ji Yoon, Cha;Hae Won, Jang;Hae In, Yong;Yun-Sang, Choi
    • Journal of Animal Science and Technology
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    • v.64 no.3
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    • pp.409-431
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    • 2022
  • Various insects have emerged as novel feed resources due to their economical, eco-friendly, and nutritive characteristics. Fish, poultry, and pigs are livestock that can feed on insects. The digestibility of insect-containing meals were presented by the species, life stage, nutritional component, and processing methods. Several studies have shown a reduced apparent digestibility coefficient (ADC) when insects were supplied as a replacement for commercial meals related to chitin. Although the expression of chitinase mRNA was present in several livestock, indigestible components in insects, such as chitin or fiber, could be a reason for the reduced ADC. However, various components can positively affect livestock health. Although the bio-functional properties of these components have been verified in vitro, they show positive health-promoting effects owing to their functional expression when directly applied to animal diets. Changes in the intestinal microbiota of animals, enhancement of immunity, and enhancement of antibacterial activity were confirmed as positive effects that can be obtained through insect diets. However, there are some issues with the safety of insects as feed. To increase the utility of insects as feed, microbial hazards, chemical hazards, and allergens should be regulated. The European Union, North America, East Asia, Australia, and Nigeria have established regulations regarding insect feed, which could enhance the utility of insects as novel feed resources for the future.

Daoist Thought through Symbols Observed in the Architecture of Tu An Hieu Nghia Pagodas and Temples from the Tri Tôn District, An Giang Province

  • NGUYEN Trung Hieu;NGUYEN Phuoc Tai
    • Journal of Daesoon Thought and the Religions of East Asia
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    • v.2 no.2
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    • pp.101-121
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    • 2023
  • Daoism was introduced into the South-West of Vietnam via two main entries: the missionaries from North and Central Vietnam who migrated to the South by following the Southward movement and the spread of Daoism by Chinese migrant men who came and settled in the South-West of Vietnam from the late seventieth century to late nineteenth century. However, the biggest influence of Daoism in the Southwest of Vietnam was mainly the Chinese missionaries of Daoism. As time went by, together with the impacts of social and historical circumstances, Daoism had a strong influence on the lives of the South-West people in terms of different aspects, especially their faith and religions. The impact of Daoism into people's faith and religion was considerable, especially to the indigenous religions, of which the religion, Four Debts of Gratitude, is a representative example. With the aims of clarifying how Four Debts of Gratitude was influenced by Daoist thought and how the indigenous religions and systemized ideologies in the South-West of Vietnam were related during the period of living condition expansion as well as cohabitation of several ethnic groups in the region, this article focuses on Daoist thought expressed in typical symbols in the sacred architecture of the Four Debts of Gratitude such as Cổ Lầu, wine gourds, and the Eight Trigrams. Once properly examined, it becomes clear that the prominent symbols and other Daoist elements show that Daoism had a profound influence on the Four Debts of Gratitude.

IFFAS (International Federation of Foot & Ankle Societies) 2024 Conference Report (IFFAS (International Federation of Foot & Ankle Societies) 2024 학술대회 보고서)

  • Jiyoun Kim;Sung Hun Won;Yeo Kwon Yoon;Jae Yong Park
    • Journal of Korean Foot and Ankle Society
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    • v.28 no.3
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    • pp.81-86
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    • 2024
  • The International Federation of Foot and Ankle Societies (IFFAS) is a global organization for foot and ankle societies, comprising the Asian Federation of Foot and Ankle Surgeons (AFFAS), the European Foot and Ankle Society (EFAS), the Latin American Federation of Medicine and Surgery of the Foot and Leg (FLAMECIPP), the North American Federation of Foot and Ankle Societies (NAFFAS), and the Southern Federation of Foot and Ankle Society. Since 2005, IFFAS has organized worldwide conferences every three years, starting in Naples, Italy. The 2020 conference in Chile was postponed to 2022 due to COVID-19 pandemic and became biennial with the founding of the Southern Federation. Consequently, the conference is set to take place in Seoul in 2024. IFFAS 2024 was the first global foot and ankle conference held post-pandemic and significant as the first IFFAS event in Asia since the 2011 conference was canceled because of the Great East Japan Earthquake. Under the theme "Meet the knowledge and beautifulness," the event was hosted in Seoul. The academic program included an AFFAS-hosted event on May 30, followed by the IFFAS-hosted conference from May 31 to June 1, with all events organized by the Korean Foot & Ankle Society (KFAS).

Perspective of breaking stagnation of soybean yield under monsoon climate

  • Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.8-9
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    • 2017
  • Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

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Synoptic Characteristics of the Main Path Types of 850hPa Surface Water Vapor Flux for Heavy Changma Rainfall in the South Coastal Region of Korea (한국 남해안의 장마철 호우 시 850hPa 등압면 수증기 수송 주 경로 유형의 종관 특성)

  • Park, Byong-Ik
    • Journal of the Korean association of regional geographers
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    • v.17 no.2
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    • pp.150-166
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    • 2011
  • This study aims to investigate the differences of synoptic characteristics and frontal structures over East Asia according to the main path types of water vapor flux (WVF) of 850hPa surface in cases of the heavy rainfall in the south coastal region of Korea during the Changma season (June and July), In the cases of type A in which the main path of WVF is running from the South china Sea via the South china to the South Sea of Korea, the North Pacific subtropical anticyclone (NPSA) expands to the South China and strong cyclones appear in the Yellow Sea. In cases of type B and C in those the main paths of WVF are running from the South China Sea via the Western Pacific Ocean near Taiwan to the South Sea and from the Western North Pacific Ocean to the South Sea respectively, tropical cyclones appear frequently near Taiwan and the NPSA shifts northward. In the case of type D in which the main path of WVF appear only near the South Sea, strong cyclones appear near the Yellow Sea. In all cases upper jets are intensified in the northern part of the heavy rainfall region and low-level jets appear near the main paths of WVF. In the view of frontal structure, deep active-type of the Changma front is identified in most cases of all types. In this point the Changma season is different from the Baiu season in Western Japan where many cases of shallow active-type of the Baiu front appear.

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Research on Measures to Enhance Railroad Security Checks of Railroad Police Officers to Prevent Terrorist Attacks (철도테러 예방을 위한 철도경찰 보안검색 강화 방안 연구)

  • Gwon, Hyeon-Shik
    • Korean Security Journal
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    • no.49
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    • pp.157-183
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    • 2016
  • Countries across the globe, including those in Europe, are waging a "war against terrorism" as international terrorist groups such as ISIS and lone-wolf terrorists have unleashed various large-scale attacks on rail infrastructure. Anti-South Korean sentiment exists in Muslim-majority countries because the nation has cooperated with the US for its military interventions in the Middle East, and ISIS has threatened to target South Korea four times since September 9, 2015. In addition, North Korea has been left isolated in the international community with its missile and nuclear tests, while further escalating inter-Korean tension and threatening to strike major facilities and attack important figures in the South. These situations imply that South Korea is no longer immune to terrorist attacks. If the nation fails to prevent or deter such terrorist attacks against rail networks, massive casualties, property damage and social confusion would be unavoidable, deteriorating national and international trust in its counter-terrorism policies. This may lead to a national crisis involving decreases in the number of tourists, dampened interest of foreign investors, and capital flight. This study aims to propose policy measures to enhance railroad security checks, based on the work of railroad police officers, for the sake of protecting citizens and public safety. The suggestions include an incremental expansion of railroad security checks; growth of the railroad police force and adjustment of their policing distribution with other police officers; enhancement of security systems across important rail networks; improvement of the Railroad Safety Act; Southeast Asia, including the corresponding strengthening of the national crackdown illegal immigrants, and plans for pre-emptive and regular cooperation among organizations related to the promotion of security checks and the prevention of terrorist attacks.

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Home Range of Juvenile Chinese Egrets Egretta eulophotes during Post-fledging Stage in Chilsan Archipelago, Republic of Korea (칠산도 노랑부리백로 유조의 이소 후 하절기 행동권)

  • Son, Seok-Jun;Oh, Jung-Woo;Hyun, Bo-Ra;Kang, Jung-Hoon
    • Korean Journal of Environment and Ecology
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    • v.35 no.2
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    • pp.98-105
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    • 2021
  • Understanding the migration patterns and habitats of juvenile birds during the post-fledging stage is very important for conservation and management of individuals. The Chinese Egret is an internationally protected species. During the wintering season, they inhabit South-East Asia, such as the Philippines, Malaysia, and Taiwan, and breed in China, Russia, and uninhabited islands on the west coast of Korea. IIn this study, we attached a GPS telemetry tracking device to six juvenile Chinese Egrets breeding on Chilsan Archipelago in 2018 and 2019 to identify habitats by analyzing the home range during the post-fledging stage in the summer season. The individual CE1801 moved north and then returned to the Yeonggwang Baeksu tidal flat area, and CE1802 and CE1803 migrated north and inhabited Taean-gun. In 2019, CE1901 showed a similar pattern to CE1801, and CE1902 migrated southward to the Wando-gun area, while CE1903 moved south to the Sinan-gun area then returned to the Yeonggwang Baeksu tidal flat area, showing KDE 50%. The study results confirmed that the Chinese Egret moved broadly around the flat tidal area on the west coast to find a stable habitat during the post-fledging stage. Efforts to protect the habitat, such as limiting the development of this area and restricting human access, are necessary.