• Title/Summary/Keyword: Seasonal trend

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Evaluation of the Troposphere Ozone in the Reanalysis Datasets: Comparison with Pohang Ozonesonde Observation (대류권 오존 재분석 자료의 품질 검증: 포항 오존존데와 비교 검증)

  • Park, Jinkyung;Kim, Seo-Yeon;Son, Seok-Woo
    • Atmosphere
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    • v.29 no.1
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    • pp.53-59
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    • 2019
  • The quality of troposphere ozone in three reanalysis datasets is evaluated with longterm ozonesonde measurement at Pohang, South Korea. The Monitoring Atmospheric Composition and Climate (MACC), European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERAI) and Modern Era Retrospective-Analysis for Research and Applications version 2 (MERRA2) are particularly examined in terms of the vertical ozone structure, seasonality and long-term trend in the lower troposphere. It turns out that MACC shows the smallest biases in the ozone profile, and has realistic seasonality of lower-tropospheric ozone concentration with a maximum ozone mixing ratio in spring and early summer and minimum in winter. MERRA2 also shows reasonably small biases. However, ERAI exhibits significant biases with substantially lower ozone mixing ratio in most seasons, except in mid summer, than the observation. It even fails to reproduce the seasonal cycle of lower-tropospheric ozone concentration. This result suggests that great caution is needed when analyzing tropospheric ozone using ERAI data. It is further found that, although not statistically significant, all datasets consistently show a decreasing trend of 850-hPa ozone concentration since 2003 as in the observation.

Pasture Vegetation Changes in Mongolia

  • Erdenetuya, M.
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.105-106
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    • 2004
  • The NDVI(normalized difference vegetation index) dataset is unique or main tool to assess the global, multi seasonal, multi annual, and multi spectral changes over the World. These features are useful for environmental studies in particular, for the vegetation coverage monitoring of the country as Mongolia, where are large pastureland and pastoral animal husbandry, which dependent on natural conditions. Pasture vegetation cover is changing accordingly with both of global climate change and anthropogenic effect or human impacts. Using past 20 years (1982-2001) NDVI derived from NOAA satellite, its dynamical trend has been decreased in all natural zones differently. Also applied the method named "Two Years Differences" which could calculate the number of years with increased or decreased NDVI values at the same place. From May to September have occurred the 9 years maximum decreases of NDVI over Mongolia, but it obtained differently in spatial and temporal scale. In 24.4 ? 32.7% of all territory occurred one year decrease of NDVI and in 18% occurred more than 3 years frequent decrease of NDVI. According to the linear trend of NDVI and in 18% occurred more than 3 years frequent decrease of NDVI dynamics over 69% of whole territory of Mongolia NDVI values had been decreased due to both natural and human induced impacts to the pasture condition. In this paper also included some results of the integrated analyses of NOAA/NDVI and ground truth data over Monglia separately by natural zones.

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Estimations and Long-term Trend of Sea-to-air Dimethyl Sulfide (DMS) Flux using Satellite Observation Data (인공위성 관측 자료를 이용한 해양-대기 DMS flux 추정 및 장기 추세 분석)

  • Choi, Yu-Na;Song, Sang-Keun;Han, Seung-Beom;Son, Young-Baek;Park, Yeon-Hee
    • Ocean and Polar Research
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    • v.39 no.3
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    • pp.181-194
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    • 2017
  • The long-term linear trend of global sea-to-air dimethyl sulfide (DMS) flux was analyzed over a 16-year time span (2000~2015), based on satellite observation data. The emission rates of DMS (i.e. DMS flux) in the global ocean were estimated from sea surface DMS concentrations, which were constructed with chlorophyll a (Chl-a) concentrations and mixed layer depths (MLD), and transfer velocity from sea to air, which was parameterized with sea surface wind (SSW) and sea surface temperature (SST). In general, the DMS flux in the global ocean exhibited a gradual decreasing pattern from 2000 (a total of 12.1 Tg/yr) to 2015 (10.7 Tg/yr). For the latitude band ($10^{\circ}$ interval between $0^{\circ}$ and $60^{\circ}$), the DMS flux at the low latitude of the Northern (NH) and Southern hemisphere (SH) was significantly higher than that at the middle latitude. The seasonal mean DMS flux was highest in winter followed by in summer in both hemispheres. From the long-term analysis with the Mann-Kendall (MK) statistical test, a clear downward trend of DMS flux was predicted to be broad over the global ocean during the study period (NH: $-0.001{\sim}-0.036{\mu}mol/m^2/day\;per\;year$, SH: $-0.011{\sim}-0.051{\mu}mol/m^2/day\;per\;year$). These trend values were statistically significant (p < 0.05) for most of the latitude bands. The magnitude of the downward trend of DMS flux at the low latitude in the NH was somewhat higher than that at the middle latitude during most seasons, and vice versa for the SH. The spatio-temporal characteristics of DMS flux and its long-term trend were likely to be primarily affected not only by the SSW (high positive correlation of r = 0.687) but also in part by the SST (r = 0.685).

A Study of Fashion and Make-up Trend in 1990s (1990년대의 패션과 메이크업 경향에 관한 연구)

  • 김수진;한명숙
    • The Research Journal of the Costume Culture
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    • v.6 no.1
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    • pp.84-93
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    • 1998
  • The main focus of this paper is to provide clear understanding about the concept of make-up as total fashion by defining the essential meaning of it. First, we would like to go over the concept of make-up and total fashion, then analyze the make-up image, the changes of colors and images of make-up overtime and fashion that have influenced over those changes. In this paper, we analyze the trend of fashion and make-up in 1990s and their relevancy. Through this paper we hope that make-up can be accepted as a part of total fashion in its relationship with other elements such as shoes, clothes and accessory and that it can be considered as a independent art that has direct influence on people. The trend of Spring/Summer between 1990 and 92is the image of natural beauty and comfortable and modernistic image that can be experienced through nature. In 1992, there was a revival look of 1960s and 1970s. Make-up also followed this trend. The overall color tone was to give natural and stable images with pastel tone to soften the images. This tone brought back the ecology of 1960s. The theme of restoration in humanity and nostalgia was reflected in clothing, and these trend changed the ecology of make-up to peace, love and romantic ecology which was expressed in coral, blue, and green tone to create intelligent image of woman. Year 1996 could be called as color revolution period that emphasized the unique and individual expression of each person. In 1997, black, pastel and brown colors were the result of reinterpreting the classic and sexy images of 1960s to natural and modernistic image of 1997. Purple color started to be introduced to us. The beginning of 1990s Fall/Winter season was based on ecology concept that emphasized the natural image. Until 1995 it appeared that spring/summer and fall/winter trend had no big differences. But from 1995 seasonal differences in trend are appeared and there were various make-up designs. In 1995, 1996, brown color lines make-up comes to mix with romantic image and developed into wine, orange, neon colors. These color were the symbol of property and sentiment and gold make-up emphasizing the eye area was the tendency of that period. In 1997, the fear of coming end of century was expressed as decadent image and at that time ethnic image, romantic image appeared with vivid color lines, gold, red and violet.

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Seasonal Sedimentary Characteristics and Depositional Environments after the Construction of seawall on the Iwon Macrotidal Flat (방조제 건설 후 이원 대조차 조간대의 계절별 퇴적학적 특성 및 퇴적환경)

  • Kum, Byung-Cheol;Park, Eun-Young;Lee, Hi-Il;Oh, Jae-Kyung;Shin, Dong-Hyeok
    • Journal of the Korean earth science society
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    • v.25 no.7
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    • pp.615-628
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    • 2004
  • In order to elucidate seasonal sedimentary characteristics and depositional environment after construction of seawall on macrotidal flat, a seasonal observations of surface sediments (total 450) and sedimentation rates on 4 transects have been investigated for 2 years. The eastern area of Iwon tidal flat, has been changed from semi-closed coast to open coast by construction of seawall, shows general seasonal changes similar to characteristics of open coast type, which represented both fining and bad sorted distribution due to deposition of fine sediments under low energy condition in the summer, and relatively coarser and better sorted distribution because of erosion of fine sediments in the winter. In considering angles of transects, distribution patterns of surface sediments, the northern and southern parts of eastern tidal flat are dominantly influenced by wave and tidal effects, respectively. As time goes by, the eastern tidal flat shows coarsening-trend of surface sediments caused by direct effect of tidal current, were and typhoon. Meanwhile the western area of seawall, which has been re-formed by construction seawall, is sheltered from northwesterly seasonal wind. The seasonal change pattern of western area of seawall is slightly different from that of eastern tidal flat. Mean grain size and sorting of surface sediments during spring is finer and worse than those during summer. This seasonal change pattern maybe influenced by topographic effects caused from the construction of seawall. In consideration of all result, the transport of fine sediments in the study area, which is supplied to limited sediments, shows clockwise circulation pattern that fine sediments are transported from the eastern tidal flat to the western area of seawall because of blocking of seawall in the winter and are transported reversed direction the summer. As a result, many changes have been observed in the study area after construction of seawall; however, this change is still in progress and is expected to need continuous monitoring.

The Demersal Fish of Asan Bay -IV. Temporal Variation in Species Composition from 1990 to 1993- (아산만 저어류 -IV 종조성의 최근 3년간(1990-1993) 변화-)

  • LEE Tae-Won;HWANG Sun-Wan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.1
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    • pp.67-79
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    • 1995
  • Temporal variation of demersal fish in Asan Bay was determined by analyzing seasonal samples collected by an otter tyawl from November 1990 to August 1993. Of 49 species identified, Cynogiossus joyneri, Thrissa koreans and Johnius belengerii predominated in abundance, consisting of $84.7\%$ in fish numbers and $70.5\%$ in biomass. The number of species did not show any significant seasonal variation. Fish numbers and biomass were comparatively high 3n spring, summer and tall, and low in winter. Community structure, analyzed by principal component analysis using rank correlation, showed a clear seasonal trend, which seems to be related to the seasonal effects such as temperature. The number of species and their abundance in the study area were lower than those in other embayments of Korean peninsula. It seems that unstability of the sediments by tidal mixing caused this phenomenon. The total number of species decreased annually. The species of which the frequency of occurrence tends to diminish as time were mainly composed of the species which rarely occurred with low abundance.

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Earthworm Composition and Seasonal Population Structure in Different Korean Golf Courses (우리나라 골프장의 지렁이 종 다양성 및 계절별 군집 구조)

  • Shin, Chong Chang;Hong, Yong;Lee, Dong Woon
    • Weed & Turfgrass Science
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    • v.5 no.3
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    • pp.155-164
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    • 2016
  • Earworm is very useful animal in soil ecosystem, however it is harmful for golf courses because they introduce many cast on turfgrass that reduces turf uniformity and play quality. However, no information has found on earthworm diversity and seasonal fluctuation in different Korean golf courses. In this study, we focused to carry out earthworm species composition and seasonal population structure in turfgrass of golf courses. During spring and fall season survey with direct digging and tea saponin drenching sampling in 5 different golf courses, 6 species under 3 families of earthworms were collected. Earthworm species composition and density was different among the golf courses. Aporrectodea caliginosa in Lumbricidae was dominant species in Anseong and Dongrae Benest Golf Club; however Amynthas carnosus in Megascolecidae was dominant species in Anyang and Glenrose Golf Club. Ap. caliginosa was collected only aclitellum in July and Am. carnosus was collected aclitellum and clitellum in August in golf courses. Seasonal population of earthworm was different depending on earthworm species (Am. hupeiensis was the highest in August and Ap. caliginosa was in April) however small number of collected earthworm species were not dominant trend in golf courses.

Seasonal Variation of Lipids and Fatty Acids of Sharp Toothed Eel(Muraenesox cinereus) (갯장어의 일반성분과 지방산의 계절적 변화)

  • 안창범;신태선
    • Journal of Life Science
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    • v.12 no.3
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    • pp.233-241
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    • 2002
  • Seasonal variation of uraenesox cinereus) muscle was investigated. Crude lipid content varied from 3.85 to 12.59 g/100g, comprising the highest content in November. The major fatty acids of total lipid, neutral lipid, and phospholipid were C16:0, C23:0, C16:1, C18:1, C20:5, and C22:6, but in phospholipid, Cl8:3n-6 was also the major fatty acid. The C22:6 content of the neutral lipid was much lower compared to that of the total lipid and phospholipid. The content of polyunsaturated fatty acids (ranged from 73.93 to 66.23%) in phospholipid was higher than that of any other lipid fraction. In glycolipid, C20:1 and C14:1 were higher compared to those of any other lipid fraction, but C20:5 and C22:6 were lower. The annual average ratio of n-3 to n-6 of total lipid, neutral lipid, phospholipid, and glycolipid was 10.82, 12.27, 6.63, and 6.50, respectively. The particular trend of seasonal variation of fatty acid composition was not showed in total and neutral lipid. However, the samples caught in September and November had a high crude lipid content with a significantly lower content of polyunsaturated fatty acids in phospholipid. Also, the content of monounsaturated fatty acids in glycolipid was lower in samples of September, November, and January.

A Nonparametric Long-Term Trend Analysis Using Water Quality Monitoring Data in Nam-River (남강 수질측정망 자료를 이용한 비모수적 장기 수질 추세 분석)

  • Jung, Kang-Young;Kim, Myojeong;Song, Kwang Duck;Seo, Kwon Ok;Hong, Seong Jo;Cho, Sohyun;Lee, Yeong Jae;Kim, Kyunghyun
    • Journal of Environmental Science International
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    • v.27 no.11
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    • pp.1029-1048
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    • 2018
  • In this study, seasonal Mann - Kendall test method was applied to 12 stations of the water quality measurement network of Nam-River based on data of BOD, COD, TN and TP for 11 years from January 2005 to December 2015 The changes of water quality at each station were examined through linear trends and the tendency of water quality change during the study period was analyzed by applying the locally weighted scatter plot smoother (LOWESS) method. In addition, spatial trends of the whole Nam-River were examined by items. The flow-adjusted seasonal Kendall test was performed to remove the flow at the water quality measurement station. As a result, BOD, COD concentration showed "no trand" and TN and TP concentration showed "down trand" in regional Kendall test throughout the study period. BOD and TP concentration in "no trand", COD, and TN concentration showed an "up trand" tendency in Nam-River dam. LOWESS analysis showed no significant water quality change in most of the analysis items and stations, but water quality fluctuation characteristics were shown at some stations such as NR1 (Kyungho-River 1), NR2 (Kyungho-River 2), NR3 (Nam-River), NR6 (Nam-River 2A). In addition, the flow-adjusted seasonal Kendall results showed that the BOD concentration was "up trand" due to the flow at the NR3 (Nam-River) station. The COD concentration was "up trand" due to the flow at NR1 (Kyungho-River 1) and NR2 (Kyungho-River 2) located upstream of the Nam-River. The effect of influent flow on water quality varies according to each site and analysis item. Therefore, for the effective water quality management in the Nam-River, it is necessary to take measures to improve the water quality at the point where the water quality is continuously "up trand" during the study period.

Analysis of Variation Characteristics of Greenhouse Gases in the Background Atmosphere Measured at Gosan, Jeju (한반도 배경대기 중 온실기체의 농도 변동 특성 분석)

  • Ju, Ok-Jung;Cha, Jun-Seok;Lee, Dong-Won;Kim, Young-Mi;Lee, Jung-Young;Park, Il-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.4
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    • pp.487-497
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    • 2007
  • Increase of the greenhouse gases emissions during last century has led remarkable changes in our environment and climate system. Continuous monitoring of atmospheric constituents over the world is positively necessary to understand these changes around us. The concentrations of greenhouse gases ($CO_2,\;CH_4,\;N_2O,\;CFCs$) have been continuously measured at Global Climate Change Monitoring station in Gosan, Jeju since January, 2002. In this study, the variation characteristics of greenhouse gases as well as their annual, seasonal and diurnal trend using the data from January, 2002 to December, 2005 were analyzed. The raw data which was used in the analysis were validated with the methods recommended by WDCGG (World Data Center for Greenhouse Gases). The concentration of $CO_2$ was increasing continuously by 2.1 ppm/year, while $CH_4$ did not show any increasing or decreasing trend clearly for 4 years. The concentration of $N_2O$ was slightly increasing and CFCs were decreasing except CFC-12 which has longer lifetime compared with other CFCs. The variations of the greenhouse gases at Gosan were shown to be consistent with the global trend. But the concentration level of $CO_2$ in Korea was more or less higher than abroad.