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161.
Eun Jin Kim Sok Kuh Kang Sung-Tae Jang Jae Hak Lee Young Ho Kim Hyoun-Woo Kang Yeong Yeon Kwon Young Ho Seung 《Ocean Science Journal》2010,45(3):159-170
Satellite-derived sea surface temperature (SST) is validated based on in-situ data from the East China Sea (ECS) and western North Pacific where most typhoons, which make landfall on the Korean peninsula, are formed and pass. While forecasting typhoons in terms of intensity and track, coupled ocean-typhoon models are significantly influenced by initial ocean condition. Potentially, satellite-derived SST is a very useful dataset to obtain initial ocean field because of its wide spatial coverage and high temporal resolution. In this study, satellite-derived SST from various sources such as Tropical Rainfall Measuring Mission Microwave Imager (TMI), Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and New Generation Sea Surface Temperature for Open Ocean (NGSST-O) datasets from merged SSTs were compared with in-situ observation data using an indirect method which is using near surface temperature for validation of satellite derived SST. In-situ observation data included shipboard measurements such as Expendable Bathythermograph (XBT), and Conductivity, Temperature, Depth (CTD), and Argo buoy data. This study shows that in-situ data can be used for microwave derived SST validation because homogeneous features of seawater prevail at water depths of 2 m to 10 m under favorable wind conditions during the summer season in the East China Sea. As a result of validation, root-mean-square errors (RMSEs) are shown to be 0.55 °C between microwave SST and XBT/CTD data mostly under weak wind conditions, and 0.7 °C between XBT/CTD measurement and NGSST-O data. Microwave SST RMSE of 0.55 °C is a potentially valuable data source for general application. Change of SST before and after typhoon passing may imply strength of ocean mixing due to upwelling and turbulent mixing driven by the typhoon. Based on SST change, ocean mixing, driven by Typhoon Nari, was examined. Satellite-derived SST reveals a significant SST drop around the track immediately following the passing of Typhoon Nari in October, 2007. 相似文献
162.
Aerosol retrieval algorithms for the MODerate Resolution Imaging Spectroradiometer (MODIS) have been developed to estimate aerosol and microphysical properties of the atmosphere, which help to address aerosol climatic issues at global scale. However, higher spatial resolution aerosol products for urban areas have not been well researched mainly due to the difficulty of differentiating aerosols from bright surfaces in urban areas. Here, a new aerosol retrieval algorithm using the MODIS 500 m resolution image... 相似文献
163.
Determination of Partition Coefficients for Selected PAHs between Water and Dissolved Organic Matter
The fate and transport of highly hydrophobic chemicals are affected by the partitioning between water and dissolved organic carbon. Large variation in the partition coefficient (KDOCw) is often found, due to the selection of model organic matter or potential experimental artifacts. To investigate the roles of the type of organic matter on the partitioning of highly hydrophobic compounds, the partition coefficients of eight selected polycyclic aromatic hydrocarbons (PAHs), with 3–6 aromatic rings, were determined using a passive dosing/extraction method between water and model dissolved organic matter (humic acid, fulvic acid, sodium dodecyl sulfate micelle (SDS), and 2‐hydroxypropyl‐β‐cyclodextrin). Although the KDOCw values for 3–4 ring PAHs in this study were close to those reported in the literature, experimental KDOCw values between Aldrich humic acid (AHA) and water were higher than values reported in the literature for 5–6 ring PAHs. The KDOCw values were highest for AHA, followed by SDS and Suwannee river fulvic acid (SFA). The slopes of the linear regression between log KDOCw and log Kow were 1.23 (± 0.13), 0.82 (± 0.09), and 0.59 (± 0.13) for AHA, SDS, and SFA, respectively. The differences in the KDOCw values between AHA and the other organic matter (SDS, SFA, and CD) increased with increasing hydrophobicity of the PAHs, showing that the sorption of highly hydrophobic chemicals to the humic acid fraction may be important in the presence of mixed organic matter. 相似文献
164.
165.
Jae-Hyun Lim Seunghyun Son Jung-Woo Park Jung Hyun Kwak Chang-Keun Kang Young Baek Son Jung-No Kwon Sang Heon Lee 《Ocean Science Journal》2012,47(3):377-385
The high primary production enhanced by anticyclonic eddies and hourly variation pattern in the productivity during the spring season in the East Sea were first investigated using the first Korean Geostationary Ocean Color Imager (GOCI). Even though the stratification for a seasonal spring bloom is not well developed in the water column in early April in the East Sea, a physical upward water flux movement at the periphery of the anticyclonic eddies could remain the phytoplankton in euphotic zone to sustain high chlorophyll-a concentration conditions in the Ulleung Basin. At this time, nutrients were no major controlling factor for phytoplankton growth since concentrations of major nutrients (nitrate, silicate, and phosphate) were relatively high in the observed eddy sites based on the observation data from the Korean Oceanographic Data Center (KODC). The estimated mixed layer depth (MLD) significantly shallower at the periphery supports for this mechanism. The hourly primary productivity estimation based on a Carbon-based Productivity Model (CbPM) provides a bimodal pattern along the time especially in L1 with an approximately one order magnitude difference between the lowest and highest values of productivities on 5 April, 2011. Potential possibilities for this large discrepancy in the hourly productivity and some thoughts on a short time in situ incubation method were discussed. 相似文献
166.
Accuracy of nonlinear static procedures for the seismic assessment of shear critical structures
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The nonlinear behavior of reinforced concrete (RC) members represents a key issue in the seismic performance assessment of structures. Many structures constructed in the 1980s or earlier were designed based on force limits; thus they often exhibit brittle failure modes, strength and stiffness degradation, and severe pinching effects. Field surveys and experimental evidence have demonstrated that such inelastic responses affect the global behavior of RC structural systems. Efforts have been made to consider the degrading stiffness and strength in the simplified nonlinear static procedures commonly adopted by practitioners. This paper investigates the accuracy of such procedures for the seismic performance assessment of RC structural systems. Refined finite element models of a shear critical bridge bent and a flexure‐critical bridge pier are used as reference models. The numerical models are validated against experimental results and used to evaluate the inelastic dynamic response of the structures subjected to earthquake ground motions with increasing amplitude. The maximum response from the refined numerical models is compared against the results from the simplified static procedures, namely modified capacity spectrum method and coefficient method in FEMA‐440. The accuracy of the static procedures in estimating the displacement demand of a flexure‐critical system and shear‐critical system is discussed in detail. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
167.
The western South Korea Plateau in the East Sea (Sea of Japan) is occupied by rifted continental fragments formed in association
with the early phase of back-arc opening. The present study focuses on the seismic stratigraphy of the sedimentary succession
and the underlying acoustic basement in this region, based on closely spaced multichannel seismic reflection profiles. The
sedimentary succession occurs mainly within a series of subparallel basement troughs (grabens or half grabens) bounded by
faulted continental blocks (horsts) or volcanic ridges, and commonly floored by extrusive volcanic rocks showing hyperbolic
reflectors. These features are strongly suggestive of continental rifting accompanied by normal faulting, volcanic activity
and high rates of basin subsidence. The sedimentary succession can be subdivided into four seismic units. Unit 1 is characterized
by short and irregular high-amplitude reflectors and interpreted as a syn-rift deposit consisting of a non-marine volcanics/sediment
complex in topographic lows. Units 2 and 3 formed in an open marine environment during the Middle Miocene to Early Pliocene,
characterized by an onlap-fill and later draping marine sedimentary succession dominantly composed of hemipelagic sediments
and turbidites with frequent intercalation of mass-flow deposits. Along the western margin of the plateau, these units were
deformed under a compressional regime in the Early Pliocene, associated with the back-arc closing phase. Unit 4 (deposited
since the Early Pliocene) comprises hemipelagic sediments and turbidites with evidence of sporadic slides/slumps. 相似文献
168.
Yeon S. Chang Jong Dae Do Weon Mu Jeong Sang Kwon Hyun Won-Dae Baek Jae Ho Choi Jae-Youll Jin 《Ocean Science Journal》2020,55(1):1-16
Beach erosion is a serious problem that can be aggravated by human-made structures, and the modeling of breaking waves near the coast and around coastal st 相似文献
169.
ReviewoftheResearchesonChangmaandFutureObservationalStudy(KORMEX)Jai-HoOh,Won-TaeKwonandSang-BomRyoMETRI,KoreaMeteorologicalA... 相似文献
170.
An analysis of simulated future surface climate change over the southern half of Korean Peninsula using a RegCM3-based high-resolution
one-way double-nested system is presented. Changes in mean climate as well as the frequency and intensity of extreme climate
events are discussed for the 30-year-period of 2021–2050 with respect to the reference period of 1971–2000 based on the IPCC
SRES B2 emission scenario. Warming in the range of 1–4°C is found throughout the analysis region and in all seasons. The warming
is maximum in the higher latitudes of the South Korean Peninsula and in the cold season. A large reduction in snow depth is
projected in response to the increase of winter minimum temperature induced by the greenhouse warming. The change in precipitation
shows a distinct seasonal variation and a substantial regional variability. In particular, we find a large increase of wintertime
precipitation over Korea, especially in the upslope side of major mountain systems. Summer precipitation increases over the
northern part of South Korea and decreases over the southern regions, indicating regional diversity. The precipitation change
also shows marked intraseasonal variations throughout the monsoon season. The temperature change shows a positive trend throughout
2021–2050 while the precipitation change is characterized by pronounced interdecadal variations. The PDF of the daily temperature
is shifted towards higher values and is somewhat narrower in the scenario run than the reference one. The number of frost
days decreases markedly and the number of hot days increases. The regional distribution of heavy precipitation (over 80 mm/day)
changes considerably, indicating changes in flood vulnerable regions. The climate change signal shows pronounced fine scale
signal over Korea, indicating the need of high-resolution climate simulations 相似文献