• Title/Summary/Keyword: Seasons Change

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Hadley Circulation Strength Change in Response to Global Warming: Statistics of Good Models

  • Son, Jun-Hyeok;Seo, Kyong-Hwan
    • Atmosphere
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    • v.26 no.4
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    • pp.665-672
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    • 2016
  • In this study, we examine future changes in the Hadley cell (HC) strength using CMIP5 climate change simulations. The current study is an extension of a previous study by Seo et al. that used all 30 available models. Here, we select 18-23 well-performing models based on their significant internal sensitivity of the interannual HC strength variation to the latitudinal temperature gradient variation. The model projections along with simple scaling analysis show that the inter-model variability in the HC strength change is a result of the inter-model spread in the meridional temperature gradient across the subtropics for both DJF and JJA, not by the tropopause height or gross static stability change. The HC strength is expected to weaken significantly during DJF, while little change is expected in the JJA HC strength. Compared to the calculations with all model members, selected model statistics increase the linear correlation between the changes in HC strength and meridional temperature gradient by 13~23%, confirming the robust sensitivity of the HC strength to the meridional temperature gradient. Two scaling equations for the selected models predict changes in HC strength better than all-member predictions. In particular, the prediction improvement in DJF is as high as 30%. The simple scaling relations successfully predict both the ensemble-mean changes and model-to-model variations in the HC strength for both seasons.

Analysis of Soil Moisture Characteristics in Nut Pine Forest about Seasons and Soil Layers (잣나무림에서의 시기별 토층별 토양수분 특성분석)

  • Hong, Eun-Mi;Choi, Jin-Yong;Yoo, Seung-Hwan;Nam, Won-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.4
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    • pp.105-114
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    • 2012
  • Soil moisture plays a pivotal role in hydrological processes, especially in the forest which covers more than 64% of the national land. Soil moisture was monitored to analyze soil moisture change characteristics in terms of time and soil layers in this study. 2 Years soil moisture change data was obtained from the experimental nut pine forest and statistical analysis including auto-correlation and cross-corelation among soil moisture data from different soil layers was conducted. Using the monitored soil moisture data, a relationship between soil moisture change and precipitation was analyzed and seasonal soil moisture change characteristics were analyzed. From the result of inter-relationships among soil layers in terms of season and time lag, soil moisture change characteristics in the nut pine forest were upper soil layers were much sensitive than lowers, and seasonal variation if soil moisture for upper soil layers were bigger than lowers showing low correlation with precipitation in winter and spring due to freezing and snowfalls.

Hydro-meteorological Characteristics in Season and Solar Term According to RCP Climate Change Scenarios (RCP 기후변화 시나리오에 따른 우리나라 계절 및 절기의 수문기상학적 특성 분석)

  • Oh, Miju;Kim, Jieun;Lee, Baesung;Kim, Tae-Woong
    • Journal of Wetlands Research
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    • v.24 no.4
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    • pp.288-300
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    • 2022
  • As industrialization and urbanization progress extensively, climate change is intensifying due to greenhouse gas emissions. In Korea, the average temperature increased, and the annual precipitation also increased due to climate change. In addition, the meaning of the solar term, which expresses seasons according to the movement of the sun, is also being overshadowed. Therefore, this study investigated the seasonal changes and solar-term changes of average temperature and precipitation observed in the past as well as simulated for future RCP climate change scenarios for five major regions (Capital Region, Gyeongsang, Chungcheong, Jeolla, and Gangwon). For the seasonal length, the length of summer became longer, the length of winter became shorter nationwide, and the precipitation in summer generally increased compared to the past. In the Chungcheong area, under the RCP 8.5 scenario, the length of summer increased by 46%, precipitation increased by 16.2%, and the length of winter decreased by 31.8% compared to the past. For the solar term, the temperature rose in all seasons. In the Chungcheong area, under the RCP 8.5 scenario, the temperature of major heat increased by 15.5%, and the temperature of major cold increased by 75.7% compared to the past. The overall results showed that the hydrological characteristics of the season and solar term were identified by region, which can be used as basic data to prepare policies to respond to climate change.

Trends and Design Characteristics of Eco Fashion Design (에코패션디자인의 변화추이와 디자인 특성)

  • Kim, Sae-Bom;Lee, Kyoung-Hee
    • Fashion & Textile Research Journal
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    • v.14 no.5
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    • pp.720-729
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    • 2012
  • This study investigates trends and design characteristics of recent eco fashion designs on websites. For such purposes, 1185 pictures were collected from the websites of 12 eco fashion brands from 2006 to 2010 to analyze current status and design characteristics. Content analysis and statistical analysis using SPSS will be conducted for data analysis. The results of the research are as follows. First, the change difference according to the year of the eco fashion design. The focus was on, the natural image (from 2006 to 2008), the romantic image (from 2008 to 2009), and vintage, multi, and modern (from 2010). It was noticeable that the forms, colors, and materials changed simultaneously with the various images. The changing progress of eco fashion design was on the design changes according to fashion image changes. Second, after an examination of the characteristic difference of eco fashion designs according to seasons, the difference was shown as a natural and romantic image in the S/S season as well the vintage and classical image focused on the F/W season. It is figurative that S/S season shows a romantic image as well as magnifies a sportive image that is natural and active. Multi, natural and vintage images mostly appeared for the F/W season. In conclusion, eco fashion design is influenced by fashion trends, yearly changes, and seasons.

A Fingerprint of Global Warming Appeared in Winter Precipitation across South Korea (우리나라 겨울철 강수에 나타난 지구온난화의 징후)

  • Choi, Gwang-Yong;Kwon, Won-Tae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.992-996
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    • 2008
  • In this study, changes in precipitation across South Korea during snow seasons (November-April) and their potential are examined. Current (1973/74-2006/07) and future (2081-2100) time series of snow indices including snow season, snow-to-precipitation ratio, and snow impossible day are extracted from observed snow and precipitation data for 61 weather stations as well as observed and modeled daily temperature data. Analyses of linear trends reveal that snow seasons have shortened by 3-13 days/decade; that the snow-to-precipitation ratio (the percentage of snow days relative to precipitation days) has decreased by 4-8 %/decade. These changes are associated with pronounced formations of a positive pressure anomaly core over East Asia during the positive Arctic Oscillation winter years since the late 1980s. A snow-temperature statistical model demonstrates that the warming due to the positive core winter intensifies changes from snow to rain at the rate of $4.7cm/^{\circ}C$. The high pressure anomaly pattern has also contributed to decreases of air-sea thermal gradient which are associated with the reduction of snow could formation. Modeled data predict that a fingerprint of wintertime global warming causing changes from snow to rain will continue to be observed over the 21st century.

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Variation of Community Structure of Decapods by Season and Depth near Oryuk Islets off Busan, Korea (오륙도 주변해역 십각류의 계절별 수심별 종조성과 군집구조)

  • PARK, Hyun-Jung;PARK, Won-Gyu;CHOI, Jung-Wha;LEE, Bo-Ram
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.1
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    • pp.257-269
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    • 2017
  • The occurrence variations of decapods by season and depth off Oryuk Islets, Busan were investigated at seven stations in April and October 2009, July 2010 and January 2011. Decapods were collected by SCUBA diving at 5 m and 10 m depths. 46 species belonging to 18 families in 3 orders were identified. Pilumnus minutus, Pugettia intermedia, Pachycheles stevensii, and Paguristes japonicus were dominant species, comprising 73.0% of total decapods. P. minutus and P. intermedia were abundant in all seasons (except summer) while P. stevensii and P. japonicus were abundant in fall and summer. Dominant species were divided into three groups (resident species, seasonal species and temporary species) on the basis of their occurrence patterns. P. minutus and P. intermedia were resident species while P. stevensii, P. japonicus were temporary species. The species number, density and biomass of decapods were fluctuated by seasons. They were highest in fall and lowest in winter. This study implied that the variations of species number and density of decapods were significantly related with seasonal change of water temperature.

Evaluation of Eco-Hydrological Changes in the Geum River Considering Dam Operations : II. Hydraulic Fish Habitat Condition Analysis (댐 운영을 고려한 금강의 생태.수문학적 변화 평가 : II. 수리학적 어류서식처 조건 분석)

  • Park, Sang-Young;Kim, Jeong-Kon;Ko, Ick-Hwan
    • Journal of Korea Water Resources Association
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    • v.42 no.5
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    • pp.407-414
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    • 2009
  • A quantitative analysis was conducted to study the impacts of artificial flow alteration on fish habitate condition change in the Geum River downstream the Daechung Multi-purpose Dam (DMD). River Analysis Package (RAP) was employed for the analysis and three fish species of black shiner, long nose barbel and Korean shinner were selected as icon species. The results of the analysis showed enhaced fish habitat conditions during low flow seasons in spring and fall after DMD construction, while the impact of the Youngdam Multipurpose Dam located upstream the DMD was insignificant. This result could be attributed to the fact that the increased flow during dry seasons helped create preferable habitat conditions for the fish species tested in this study.

Seasonal and Interannual Variation in Species Composition and Abundance of Decapod Assemblages Collected using Pots in the Coastal Waters off Gori, Korea (고리 주변해역 통발에서 채집된 십각류 종조성의 계절변동과 연간변동)

  • Huh, Sung-Hoi;Park, Joo-Myun;Jeong, Dal-Sang;Baeck, Gun-Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.5
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    • pp.503-509
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    • 2010
  • The seasonal and interannual variation in the species composition and abundance of the decapod assemblage (shrimps, crabs, and hermit crabs) collected using pots in the coastal waters off Gori were studied between 2005 and 2008. During the study period, 49 decapod species belonging to 19 families were collected. The dominant species were Crangon hakodatei, Pandalus gracilis, Carcinoplax longimana, Charybdis bimaculata, Carcinoplax vestita, Diogenes edwardsii, and Dardanus arrosor. These seven species accounted for 95.46% of the total number of individuals collected. The number of species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number and biomass of individuals occurred in July 2006. The number and biomass of individuals were higher in summer and lower in winter, and the diversity indices were lower in summer than in the other seasons. The abundance of dominant species showed some seasonal and interannual change; in particular, those of C. hakodatei and P. gracilis corresponded with the bottom water temperature.

Feeding Habits of the Jack Mackerel Trachurus japonicus in the Southern Sea of the Republic of Korea (한국 남해에서 출현한 전갱이(Trachurus japonicus)의 식성)

  • Lee, Ye Ji;Lee, Jeong Hoon;Lee, Young Hye
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.1
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    • pp.64-72
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    • 2021
  • The feeding habits of the Japanese jack mackerel Trachurus japonicus were studied in the Southern Sea of the Republic of Korea. To assess the effects of season, sampling was conducted in February (winter), May (spring), and August (summer), 2020. The total length of each fish was measured in 1 cm intervals. Diet composition showed the highest species diversity during winter. Diet composition changed from copepods to euphausiids as the total length of jack mackerel increased, except during winter. The most important seasonal prey were copepods in winter and summer and euphausiids in spring. Species diversity of the zooplankton community structure was highest in winter. Among the zooplankton communities, copepods were dominant in all seasons. Species with a high electivity index in all seasons were relatively large zooplankton of ≥2 mm. Jack mackerel had ontogenetic diet change, exhibited diet selectivity depending on size, and its feeding habits were affected by the zooplankton community structure.

Behavior of Hydrogen and Organic Acids in Anaerobic Digestion of Food Wastewater (음폐수의 혐기성 소화 시 수소 및 유기산의 거동)

  • Cho, Kyungmin;Oh, Saeeun
    • New & Renewable Energy
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    • v.18 no.2
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    • pp.9-17
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    • 2022
  • In this study, we used the Flux Balance Analysis (FBA) program to examine the behavior of hydrogen and organic acids according to seasonal changes in food wastewater collected from D city. The results showed that average hydrogen conversion rates in spring, summer, autumn, and winter were 1.06, 0.71, 1.21, and 1.13 mol H2/mol of hexoseadded, respectively, indicating a significantly lower hydrogen conversion rate in summer than in other seasons. This phenomenon is believed to occur because the carbohydrate concentration of the incoming food wastewater is low. In addition, Lactobacillus, the lactic acid-producing bacterium, was 21.3% in spring, 27.2% in summer, 17.5% in autumn, and 22.6% in winter. The most distinctive feature of the microbial community in summer was that 15.3% of the Ilyobacter was analyzed. It was confirmed that Ilyobacter, which is involved in the production of acetic acid and propionic acid, is closely associated with the tendency of increasing acetic acid and propionic acid and thus contributes to organic acid change. Clostridium, a hydrogen-producing bacterium, was 76.2%, 50.8%, 78.3%, and 74%, in spring, summer, autumn, and winter, respectively. It was confirmed that Clostridium dominates the microbial community by approximately 70% or more in all seasons except summer.