• Ocean and Polar Research
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• v.43 no.4
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• pp.219-227
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• 2021

Sea surface height (SSH) anomalies were estimated from data recorded by four pressure-recording inverted echo sounders (PIESs) in the Mindanao Current region over a duration of 2 years from December 2017 to November 2019. The steric components of SSH anomalies were derived from round-trip acoustic travel times from the sea floor to the sea surface, whereas mass-loading components were derived from bottom pressures. Temporal variabilities in the total (steric and mass-loading) SSH anomalies and the steric component are extremely similar; this result implies that the steric component plays a major role in SSH anomalies in this region. Comparisons of the PIES-derived SSH anomalies with satellite-measured SSH anomalies reveal that the former has less temporal variability. Correlation coefficients between the total SSH anomalies and satellite-measured SSH anomalies are less than 0.85, which is lower than the correlation coefficient between the steric components and satellite-measured SSH anomalies.

• Journal of the korean society of oceanography
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• v.36 no.3
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• pp.59-71
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• 2001

In order to investigate the temporal variability of dissolved and particulate trace metals in the Han River, water samples were collected intermittently at two sites for 3 years (August 91 to December 94). Surface seawaters covering the range of salinity were also collected at the estuarine region to evaluate the role of estuary for the riverine fluxes of trace metals within the estuary during October 95 and 96. During the study period, dissolved metal concentrations in riverwaters varied by a factor of 5-10 for Fe, Ni, Co and Cu and 50-100 for Mn, Cd and Pb depending upon the water level; high concentration during the low water and low concentration in high water period except for Fe. The concentration of dissolved Fe increased with increasing water discharge. These concentration-discharge relationships of the studied trace metals are explained by the successive dilution of waters from two different origins, which can be presumably identified as anthropogenic discharges and watershed flushing. Although estuarine waters at early mixing region were not collected due to the difficulty of sampling, mixing behaviors of metals were inferred from the concentration-salinity relationships through the laboratory mixing experiment and field sampling, and distribution coefficients between dissolved and labile particulate phases. It is suggested that the Han River estuary plays a role of accumulating Fe, Mn, Co and Pb from riverine sources due to high turbidity caused by strong tidal current, whereas this system serves as a source of dissolved Cd due to release caused by extended residence time of riverine particles.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.355-360
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• 1998

A small package of plasma instruments, Space Physics Sensor, will monitor the space environment and its effects on microelectronics in the low altitude region as it operates on board the KOMPSAT-1 from 1999 over the maximum of the solar cycle 23. The Space Physics Sensor (SPS) consists of two parts: the Ionospheric Measurement Sensor (IMS) and the High Energy Particle Detector (HEPD). IMS will make in situ Measurements of the thermal electron density and temperature, and is expected to provide a global map of the thermal electron characteristics and the variability according to the solar and geomagnetic activity in the high altitude ionosphere of the KOMPSAT-t orbit. HEPD will measure the fluxes of high energy protons and electrons, monitor the single event upsets caused by these energetic charged particles, and give the information of the total radiation dose received by the spacecraft. The continuous operation of these sensors, along with the ground measurements such as incoherent scatter radars, digital ionosondes and other spacecraft measurements, will enhance our understanding of this important region of practical use for the low earth orbit satellites.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.284-287
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• 1999

The nose, a striking features of the human face, is regarded by many clinicians as the keystone of facial esthetics. Clinically, as the treatment of a dentofacial deformity, the soft tissue changes that occurred normally with movement of the skeletal bases. Changes of the soft tissue in the maxillary orthognathic surgery are widening of alar base, elevated nasal tip and flattening of upper lip. In addition, soft tissue change is difficult to predict, it has considerable variability in the response of soft tissue. We reviewed patients who received Le Fort I advancement osteotomy in our department and analysed preoperative and postoperative alar base width, nasal height in clinical measurement and cephalometry and patient's satisfaction of postoperative nasal appearance.

• Environmental Engineering Research
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• v.21 no.1
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• pp.58-68
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• 2016

The study explored droughts using the Standardized Precipitation Index (SPI) in the northwestern region of Bangladesh, which is the drought prone area. In order to assess the trend and variability of monthly rainfall, as well as 3-month scale SPI, non-parametric Mann-Kendall (MK) tests and continuous wavelet transform were used respectively. The effect of climatic parameters on the drought in this region was also evaluated using SPI, with the Southern Oscilation Index (SOI) by means of the wavelet coherence technique, a relatively new and powerful tool for describing processes. The MK test showed no statistically significant monthly rainfall trends in the selected stations, whereas the seasonal MK test showed a declining rainfall trend in Bogra, Ishurdi, Rangpur and Sayedpur stations respectively. Sen's slope of six stations also provided a decreasing rainfall trend. The trend of the SPI, as well as Sen's slope indicated an increasing dryness trend in this area. Dominant periodicity of 3-month scale SPI at 8 to 16 months, 16 to 32 months, and 32 to 64 months were observed in the study area. The outcomes from this study contribute to hydrologists to establish strategies, priorities and proper use of water resources.

• Journal of Environmental Impact Assessment
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• v.4 no.3
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• pp.73-86
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• 1995

This paper demonstrates Environmental Impact Assessment (EIA) has to be applied for development projects with regard to the ecological, economical and social aspects before any decisions made in the project. Korea has confronted various environmental problems during the last fifteen years, even though EIA has been enacted since 1981. The role of impact assessment in planning and policy processes should be emphasized to investigate the magnitude and intensity of the adverse influences of economic development. In the Seoul Metropolitan Region, it is necessary to apply EIA all urban projects to reduce the adverse effects of urbanization. Special attention should be given to the climatological effects throughout the urbanization process in Korea to keep the urban area energy-efficient. This study intends not only to establish basic data for national-and regional-based land-use policy in the environmental aspects, but also to provide the basic data for the possible climate model (scenarios) that may provide spatial and temporal variability by analyzing the actual climatic record. There is a noticeable impact of urbanization on the atmospheric environment in the Seoul Metropolitan Region. In this sense, the climatic aspect must be taken into consideration in the process of EIA to mitigate the well-known climatic alterations of urbanization. Moreover, the techniques of assessment should be improved by developing geo-reference data sets to build models of the global climate in response to the man-made environmental change.

• Atmosphere
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• v.18 no.4
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• pp.485-492
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• 2008

This study confirms that a decadal variation of the SST (Sea Surface Temperature) in the WNP (Western North Pacific) has an influence on the genesis and passage ofa Tropical Cyclone. The decadal mode was obtained by calculating the SST anomaly on the domain $150^{\circ}E-190^{\circ}E$, and $5^{\circ}S-5^{\circ}N$. Such decadal variation was subsequently analyzed to confirm that it is a dominant mode in central Pacific region. Next, after classifying the years into relatively positive years and relatively negative years, the characteristics of Tropical Cyclone in each year, such as a genesis and passage frequency, were investigated. Compared to the relatively negative years, during the relatively positive years, the location of Tropical Cyclone genesis was biased toward South-Eastern region, while the characteristics of the cyclone were more distinct during late season of the year trom September to December than in mid season from June to August. Examining the movement passage through the observation of passage fiequency, there was a significant difference between positive year and negative year in their passages at a 90% confidence level. Moreover, the number of Tropical Cyclone, maximum wind, and life time also showed higher values in positive years than in negative years. These features were confirmed by examining the 850hPa cyclonic flow field, vorticity field, and vertical wind shear field, all of which contribute to the genesis of a Tropical Cyclone.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.354-374
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• 2016

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the five stations of Paldang Reservoir located in the Han River during 4 years from May 2012 to December 2015. Variability of basic water quality factors were largely related with seasonal fluctuations of hydrology. Temperature stratification occurred in the deep dam station, and prolonged hypoxia was observed during the draught year. Nitrogen nutrients were increased with decreasing inflow in which changing pattern of $NH_4$ reversed to $NO_3$ by the effect of treated wastewater effluent. Phosphorus increase was manifest during the period of high inflow or severe drought. Chl-a variation was reversely related with both flow change and AGP(algal growth potential) variations. Our study demonstrated that water quality variability in Paldang Reservoir was largely attributed to both natural and operational changes of inflow and outflow (including water intake) based on major pollution source of the treated wastewater (total amount of $472{\times}10^3m^3d^{-1}$) entering to the water system from watershed. In the process of water quality variability, meteorological (e.g., flood, typhoon, abnormal rainfall, scorching heat of summer) and hydrological factors (inflow and discharge) were likely to work dynamically with nutrients pulse, dilution, absorption, concentration and sedimentation. We underline comprehensive limnological study related to hydro-meteorolology to understand short- and long-term water quality variability in river-type large reservoir and suggest the necessity of P-free wastewater treatment for the effective measure of reducing pollution level of Paldang drinking water resource.

• Journal of the Korean earth science society
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• v.38 no.5
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• pp.345-356
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• 2017

It is important to understand the variability of tropospheric ozone since it is both a major pollutant affecting human health and a greenhouse gas influencing global climate. We analyze the characteristics of East Asia tropospheric ozone simulated in a chemistry-climate model. We use a global chemical transport model, driven by the prescribed meteorological fields from an air-sea coupled climate model simulation. Compared with observed data, the ozone simulation shows differences in distribution and concentration levels; in the vicinity of the Korean Peninsula, a large error occurred in summer. Our analysis reveals that this bias is mainly due to the difference in atmospheric circulation, as the anomalous southerly winds lead to the decrease in tropospheric ozone in this region. In addition, observational data have shown that the western North Pacific subtropical high (WNPSH) reduces tropospheric ozone across the southern China/Korean Peninsula/Japan region. In the model, the ozone changes associated with WNPSH are shifted westward relative to the observations. Our findings suggest that the variations in WNPSH should be considered in predicting tropospheric ozone concentrations.

• Animal cells and systems
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• v.16 no.6
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• pp.498-505
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• 2012

This study uses the mitochondrial DNA control region to identify the genetic diversity and population structure of the marbled soles (Pleuronectes yokohamae) that inhabit Jinhae Bay and Yokji Island in the nearby sea and the adjacent waters of Namhae, Hansan Island, and Jaran Bay. Direct sequencing of the PCR products revealed 379 bp sequences with 83 variable nucleotide sites, defining a total of 91 haplotypes. The haplotype diversity was high, ranging from $0.917{\pm}0.031$ to $0.983{\pm}0.008$, and nucleotide diversity ranged from $0.015{\pm}0.008$ to $0.024{\pm}0.012$. In addition, 48 haplotypes (52.7%) were unique. Pairwise $F_{ST}$ values were very low, with the maximum value occurring between PYH (Hansan Island) and PJI (Jinhae Bay) ($F_{ST}$ = 0.011). Therefore, no significant genetic differentiation was evident between any pair of sampling localities.