• Title/Summary/Keyword: continental climate

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Variations of Sea Level and Sea Surface Temperature in Korean Seas by Topex/Poseidon and NOAA

  • Yoon, Hong-Joo;Kang, Heung-Soon;Lee, Bong-Sic;Jeong, Young-Deok
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.880-883
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    • 2006
  • Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea(Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

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Assessing the Impact of Locally Produced Aerosol on the Rainwater Composition at the Gosan Background Site in East Asia

  • Han, Yeongcheol;Huh, Youngsook
    • Asian Journal of Atmospheric Environment
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    • v.8 no.2
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    • pp.69-80
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    • 2014
  • It is often assumed that atmospheric observations at remote sites represent long-range transport of airborne material, and local influences are overlooked. We evaluated the impact of local input on the rainwater composition at Gosan Station, a strategic site for monitoring the continental outflow from Asia. We analyzed a 14-year record of rainwater chemical composition archived by the Korea Meteorological Administration and detected local terrestrial contribution for nitrate, sulfate and ammonium. We also measured the chemical composition of rainwater sampled simultaneously at multiple locations within the premises of the Gosan Station, from which local influence with meter-scale spatial heterogeneity could be discerned. We estimate that the local input accounted for at least ~10% of the wet deposition of nitrogen and ~12% of the wet deposition of sulfur during the 14 years. This highlights the significance of the local influence, which should be carefully assessed when interpreting atmospheric observations at this site.

Study on Temperature History and Compressive Strength of Mock-up Concrete Considering Seasonal Change (매스콘크리트의 계절에 따른 온도이력과 압축강도에 관한 실험)

  • Kim Young-Joo;Gong Min-Ho;Kim Kwang-Ki;Yang Dong-Il;Pack Moo-Young;Jung Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2005.11a
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    • pp.89-92
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    • 2005
  • Our country has experienced variations in temperature as belong to the area of the continental climate that shows four significant seasons. These occur quality of construction. As the hydration of cement processes, the strength of concrete is developed. In order to improve the quality of concrete, various conditions including temperature and humidity should be maintained appropriately and concrete itself should be cured sufficiently This paper is basic experiment for estimating influence of strength by seasonal mock-up concrete's heat of hydration and estimate relationship of compressive strength development by curing temperature. And show basic document as quality control.

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Extinction, Flood Basalts, and Geomagnetic Field (멸종, 범람 현무암과 지구자기장)

  • Yu, Yong-Jae
    • 한국지구물리탐사학회:학술대회논문집
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    • 2008.10a
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    • pp.33-36
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    • 2008
  • For the past 300 Ma, massive extinctions are associated with major flood basalt eruptions. The geomagnetic Superchrons (Cretaceous Normal Superchron, Kiaman Long Reversed Superchron, Moyero Long Reversed Superchron) precede the major flood basalt eruptions and massive extinctions. It is likely that upswing of mantle plumes is responsible for the generation of continental flood basalt. Eruption of flood basalts results in a catastrophic climate change as well as a massive genus depletion.

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A Experimental Study on the Properties of Concrete Strength According to Curing Condition (양생조건에 따른 콘크리트 강도 특성에 관한 실험적 연구)

  • Joung Won Seoup;Kim Kang Sik;Park Jae Woo;Noh Jea Myoung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.441-444
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    • 2005
  • Our country has experienced variations in temperature as belong to the area of the continental climate that shows four significant seasons. These occur immense difficulty on the period, cost, quality of construction. As the hydration of cement processes, the strength of concrete is developed. In order to improve the quality of concrete, various conditions including temperature and humidity should be maintained appropriately and concrete itself should be cured sufficiently. In the early age, the strength of concrete is developed remarkably. However, the hydration is accelerated too much in high temperature or delayed too much in low temperature, so the quality can be changed and It can fail to get the objective strength. This paper aims to offer the data, necessary to the quality control handbook.

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Variations of Sea Level and Sea Surface Temperature in Korean Seas by Topex/Poseidon and NOAA

  • Yoon, Hong-Joo;Kang, Heung-Soon;Cho, Han-Keun
    • Korean Journal of Remote Sensing
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    • v.23 no.1
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    • pp.59-63
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    • 2007
  • Altimeter (Topex/Poseidon) and AVHRR (NOAA) data were used to study the variations and correlations of Sea Level (SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea (Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

Application of Sedimentary Neodymium Isotopes to the Reconstruction of the Arctic Paleoceanography (퇴적물의 네오디뮴 동위원소 비를 활용한 북극 고환경 복원)

  • Kwangchul Jang;Seung-Il Nam
    • Ocean and Polar Research
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    • v.45 no.2
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    • pp.89-102
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    • 2023
  • Climate and environmental changes in the Arctic Ocean due to global warming have been linked to extreme climate change in mid-latitude regions, including the Korean Peninsula, requiring a better understanding of the Arctic climate system based on the paleo-analog. This review introduces three paleoenvironmental research cases using neodymium isotopes (143Nd/144Nd, εNd) measured on two different fractions of marine sediments: silicate-bound 'detrital' and Fe-Mn oxide-dominated 'authigenic' fractions. In the first case, detrital εNd in core HH17-1085-GC on the continental shelf off northern Svalbard was used for tracing changes in sediment provenance and associated glacier behavior over the last 16.3 ka. The second case showed the potential use of authigenic εNd as a quasi-conservative water mass tracer. Three prominent εNd peaks and troughs observed in core PS72/410-1 from the Mendeleev Ridge in the western Arctic Ocean over the past 76 ka suggested episodic meltwater discharge events during 51~46, 39~35 and 21~13 ka BP. The last case proposed the use of the difference between authigenic and detrital εNd as a proxy for reconstructing glacier fluctuation. The idea is based on the assumption that enhanced glacial erosion during glacier advances can supply sufficient freshly-exposed rock substrate for incongruent weathering, potentially leading to greater isotopic decoupling between bedrock and dissolved weathering products as recorded in detrital and authigenic εNd, respectively. Thus, it would be worthwhile to take advantage of sedimentary εNd to improve our understanding of past environmental changes in polar regions.

The US National Ecological Observatory Network and the Global Biodiversity Framework: national research infrastructure with a global reach

  • Katherine M. Thibault;Christine M, Laney;Kelsey M. Yule;Nico M. Franz;Paula M. Mabee
    • Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.219-227
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    • 2023
  • The US National Science Foundation's National Ecological Observatory Network (NEON) is a continental-scale program intended to provide open data, samples, and infrastructure to understand changing ecosystems for a period of 30 years. NEON collects co-located measurements of drivers of environmental change and biological responses, using standardized methods at 81 field sites to systematically sample variability and trends to enable inferences at regional to continental scales. Alongside key atmospheric and environmental variables, NEON measures the biodiversity of many taxa, including microbes, plants, and animals, and collects samples from these organisms for long-term archiving and research use. Here we review the composition and use of NEON resources to date as a whole and specific to biodiversity as an exemplar of the potential of national research infrastructure to contribute to globally relevant outcomes. Since NEON initiated full operations in 2019, NEON has produced, on average, 1.4 M records and over 32 TB of data per year across more than 180 data products, with 85 products that include taxonomic or other organismal information relevant to biodiversity science. NEON has also collected and curated more than 503,000 samples and specimens spanning all taxonomic domains of life, with up to 100,000 more to be added annually. Various metrics of use, including web portal visitation, data download and sample use requests, and scientific publications, reveal substantial interest from the global community in NEON. More than 47,000 unique IP addresses from around the world visit NEON's web portals each month, requesting on average 1.8 TB of data, and over 200 researchers have engaged in sample use requests from the NEON Biorepository. Through its many global partnerships, particularly with the Global Biodiversity Information Facility, NEON resources have been used in more than 900 scientific publications to date, with many using biodiversity data and samples. These outcomes demonstrate that the data and samples provided by NEON, situated in a broader network of national research infrastructures, are critical to scientists, conservation practitioners, and policy makers. They enable effective approaches to meeting global targets, such as those captured in the Kunming-Montreal Global Biodiversity Framework.

Syntaxonomical and Synecological Description on the Forest Vegetation of Juwangsan National Park, South Korea (주왕산국립공원 삼림식생의 군락분류와 군락생태)

  • Oh, Hae-Sung;Lee, Gyeong-Yeon;Kim, Jong-Won
    • Korean Journal of Environment and Ecology
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    • v.32 no.1
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    • pp.118-131
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    • 2018
  • The forest vegetation of Juwangsan National Park, which is famous for its towering scenic valleys, was syntaxonomically described. The study adopted the $Z{\ddot{u}}rich$-Montpellier School's method emphasizing a matching between species composition and habitat conditions. A combined cover degree and the r-NCD (relative net contribution degree) were used to determine a performance of 265 plant species listed-up in a total of 52 phytosociological $relev{\acute{e}}s$. Nine plant communities were classified through a series of table manipulations, and their distribution and actual homotoneity($H_{act}$) were analyzed. Syntaxa described were Carex gifuensis-Quercus mongolica community, Athyrium yokoscense-Quercus mongolica communiy, Arisaema amurense-Quercus serrata community, Lespedeza maximowiczii var. tomentella-Quercus variabilis community, Tilia rufa-Quercus dentata community, Carex ciliatomarginata-Carpinus laxiflora community, Aristolochia manshuriensis-Zelkova serrata community, Onoclea orientalis-Fraxinus mandshurica community, and Carex humilis var. nana-Pinus densiflora community. A zonal distribution was reviewed and the altitude of about 700 m was the transition zone between the cool-temperate central montane zone (Lindero-Quercenion mongolicae region) and southern submontane zone (Callicarpo-Quercenion serratae region). Only 19 taxa were associated with r-NCD 10% or more, most of which were tree species occurring in the Lindero-Quercenion and some of which was a member of open forests. Species composition of forest vegetation was much less homogeneous, showing the lowest $H_{act}$. Nearly natural forests and/or secondary forests in the Juwangsan National Park were defined as a regional vegetation type, which reflects much stronger continental climate in the Daegu regional bioclimatic subdistrict, rhyolitic tuff predominant, and wildfire interference.

Interpretation of geological structures and stratigraphy around the Kita-Yamato Bank in the East Sea (동해 키타-야마토 뱅크 주변 해역의 지질구조 및 퇴적층서 해석)

  • Huh Sik;Yoo Hai Soo;Park Chan Hong;Han Sang Joon;Jou Hyeong Tae
    • The Korean Journal of Petroleum Geology
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    • v.9 no.1_2 s.10
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    • pp.16-23
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    • 2001
  • The study area in the East Sea is located on the northeastern margins of the Ulleung Basin near the Kita-Yamato Bank. The research area provides the important clue to the development of Miocene basins which are characterized by the normal faults and volcanic activities related to rifting in the continental crust. Kita-Yamato Bank is a small sediment-filled graben which was formed by failed rifting in the Early Miocene. The basins rapidly vary the bathymetry, depth of acoustic basement and thickness of sedimentary layer. The tension in the study area caused the extensional lithospheric deformation before/during the Early Miocene. In consequence, tectonic forces resulted in the depression or subsidence of basement from continental rifting in the Kita-Yamato Bank followed by the opening of the Ulleung Basin, and caused the onset of graben or half-graben structure bounded by large blocked syn-rift faults. Afterward no significant tectonic deformation exists, with the consequence that post-rift normal faults with small heave were formed and reactivated by the resultant forces such as tectonic subsidence, sediment loading and volcanic activity. The Cenozoic sediment layer has a maximum thickness of 1.0 s along the center of the graben or half-graben, which overlies the consolidated acoustic basement. Seismic units V and IV supposed to be syn-rift sedimentary rocks are deformed by both the volcanic activities and numerous basement-involved normal faults induced from extension. In the uppermost layer, slump scars resulted from the slope failure are recognized.

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