• Title/Summary/Keyword: seasonal patterns

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Seasonal Onset and Duration in South Korea (우리나라 사계절 개시일과 지속기간)

  • Choi, Gwang-Yong;Kwon, Won-Tae;Robinson David A.
    • Journal of the Korean Geographical Society
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    • v.41 no.4 s.115
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    • pp.435-456
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    • 2006
  • This study examines the long-term spatial patterns and recent trends of seasonal onsets and durations defined by daily temperatures in South Korea for the period 1973-2004. Spatially, spring and winter onset dates show approximately 44 day and 63 day maximum difference respectively between south and north (Seongsanpo to Daegwallryeong) attributable to the impacts of latitudes and altitudes. In contrast, summer onset, which is more affected by proximity to oceans and altitudes than by latitudes, begins earlier in interior low elevated areas than in the coastal areas but earliest at higher latitudes than Jeiu Island. Five climatic types regarding the seasonal cycles in South Korea are spatially clustered according to the combination of longer seasonal durations. As a reflection of recent climate changes on seasonal cycles in South Korea, winter duration was shortened by 10 days during the post-1988 period due to a late winter onset of 4 days and an early spring onset of 6 days. The winter reduction began in the southern regions of the Korean Peninsula in the mid-1980s and spread northward during the 1990s period, ultimately appearing everywhere. In urbanized cities, where much of the surface is covered with asphalt or concrete, the winter reduction was intensified and summer duration was locally incremented. The reduced winter duration in recent decades shows significant teleconnections with variations of geopotential height (925hPa) in the eastern Arctic region ($0-90^{\circ}E$, $65-85^{\circ}N$) during the cold season. The reduction in winter duration in South Korea agrees with results in overall global warming trends as a climate change signal.

Visual Analytics for Abnormal Event detection using Seasonal-Trend Decomposition and Serial-Correlation (Seasonal-Trend Decomposition과 시계열 상관관계 분석을 통한 비정상 이벤트 탐지 시각적 분석 시스템)

  • Yeon, Hanbyul;Jang, Yun
    • Journal of KIISE
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    • v.41 no.12
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    • pp.1066-1074
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    • 2014
  • In this paper, we present a visual analytics system that uses serial-correlation to detect an abnormal event in spatio-temporal data. Our approach extracts the topic-model from spatio-temporal tweets and then filters the abnormal event candidates using a seasonal-trend decomposition procedure based on Loess smoothing (STL). We re-extract the topic from the candidates, and then, we apply STL to the second candidate. Finally, we analyze the serial-correlation between the first candidates and the second candidate in order to detect abnormal events. We have used a visual analytic approach to detect the abnormal events, and therefore, the users can intuitively analyze abnormal event trends and cyclical patterns. For the case study, we have verified our visual analytics system by analyzing information related to two different events: the 'Gyeongju Mauna Resort collapse' and the 'Jindo-ferry sinking'.

Comparative Study on the Seasonal Predictability Dependency of Boreal Winter 2m Temperature and Sea Surface Temperature on CGCM Initial Conditions (접합대순환모형의 초기조건 생산방법에 따른 북반구 겨울철 기온과 해수면 온도의 계절 예측성 비교 연구)

  • Ahn, Joong-Bae;Lee, Joonlee
    • Atmosphere
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    • v.25 no.2
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    • pp.353-366
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    • 2015
  • The impact of land and ocean initial condition on coupled general circulation model seasonal predictability is assessed in this study. The CGCM used here is Pusan National University Couple General Circulation Model (PNU CGCM). The seasonal predictability of the surface air temperature and ocean potential temperature for boreal winter are evaluated with 4 different experiments which are combinations of 2 types of land initial conditions (AMI and CMI) and 2 types of ocean initial conditions (DA and noDA). EXP1 is the experiment using climatological land initial condition and ocean initial condition to which the data assimilation technique is not applied. EXP2 is same with EXP1 but used ocean data assimilation applied ocean initial condition. EXP3 is same with EXP1 but AMIP-type land initial condition is used for this experiment. EXP4 is the experiment using the AMIP-type land initial condition and data assimilated ocean initial condition. By comparing these 4 experiments, it is revealed that the impact of data assimilated ocean initial is dominant compared to AMIP-type land initial condition for seasonal predictability of CGCM. The spatial and temporal patterns of EXP2 and EXP4 to which the data assimilation technique is applied were improved compared to the others (EXP1 and EXP3) in boreal winter 2m temperature and sea surface temperature prediction.

Seasonal Changes of Zooplankton Communities along the Coast of Geumo Arichipelago, Yeosu (여수 금오열도 연안에서 동물플랑크톤 군집의 계절 변동)

  • Oh, Hyun-Ju;Moon, Seong Yong;Soh, Ho Young
    • Korean Journal of Environmental Biology
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    • v.31 no.3
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    • pp.192-203
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    • 2013
  • To understand the seasonal changes in the zooplankton community, we investigated their occurrence patterns and environmental factors during four seasons at 9 stations along the coast of Geumo Archipelago, Yeosu. A total of 44 taxa were sampled, with an abundance ranging from 15~$28,183inds.\;m^{-3}$, among which Noctiluca scintillans predominented. Noctiluca scintillans, Paracalaus parvus s. l., Acartia (Acartiura) omorii, Oithona spp., Aidanosagitta crassa, dedapods larvae, copepods nauplii, and copepodites were the most abundant taxa detected. Species diversity of zooplankton was high in autumn and winter, but it was relatively low in summer and spring. Non-metric multidimensional scaling (nMDS) revealed significant differences in the structures of the zooplankton community among the seasons. Our results showed that the seasonal variation in zooplankton community along the coast of Guemo Archipelago, Yeosu were attributable to seasonal changes in temperature, salinity, and Chl. a concentration. Additionally, this particularly study area might have been specifically influenced by occurs of the neritic species.

Variability of Water Quality and Limiting Factor for Primary Production in Semi-enclosed Masan Bay, South Sea of Korea (한국 남해 마산만에서 수질환경의 계절적 변동과 기초생산 제한인자)

  • Lim, Dhong-Il;Kim, Young-Ok;Kang, Mi-Ran;Jang, Pung-Kuk;Shin, Kyoung-Soon;Jang, Man
    • Ocean and Polar Research
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    • v.29 no.4
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    • pp.349-366
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    • 2007
  • Seasonal variations of various physicochemical components (temperature, salinity, pH, DO, COD, DOC, nutrients-silicate, DIN, DIP) and potential limiting factor for phytoplankton primary production were studied in the surface water of semi-enclosed Masan Bay. Seasonal variations of nutrient concentrations, with lower values in summer and winter, and higher in fall, are probably controlled by freshwater loadings to the bay, benthic flux and magnitude of occurrence of phytoplankton communities. Their spatial distributional patterns are primarily dependent on physical mixing process between freshwater and coastal seawater, which result in a decreasing spatial gradient from inner to outer part of the bay. In the fall season of strong wave action, the major part of nutrient inputs (silicate, ammonium, dissolved inorganic phosphorus) comes from regeneration (benthic flux) at sediment-water interface. During the summer period, high Si:DIN and Si:DIP and low DIN:DIP relative to Redfield ratios suggest a N- and secondarily P-deficiency. During other seasons, however, silicate is the potential limiting factor for primary production, although the Si-deficiency is less pronounced in the outer region of the bay. Indeed, phytoplankton communities in Masan Bay are largely affected by the seasonal variability of limiting nutrients. On the other hand, the severe depletion of DIN (relatively higher silicate level) during summer with high freshwater discharge probably can be explained by N-uptake of temporary nanoflagellate blooms, which responds rapidly to pulsed nutrient loading events. In Masan Bay, this rapid nutrient consumption is considerably important as it can modify the phytoplankton community structures.

Hybrid Phenomena in Modern Sports-Inspired Fashion (현대 스포츠 인스파이어드 패션에 나타난 하이브리드)

  • Lee, Young-Min;Park, Jae-Ok
    • The Research Journal of the Costume Culture
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    • v.18 no.3
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    • pp.569-587
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    • 2010
  • In the field of fashion in this modern era, the tendency of diversification has created a variety of hybrid patterns and this tendency is being accelerated simultaneously by the hybrid trend. This research aims to analyze the aesthetic features of hybrid fashion in the modern "Sports Inspired Fashion(SIF)." We analyze fashion in the past 10 years from 2001 S/S to 2010 S/S. We focus on the four largest worldwide collections from New York, Paris, Milano, and London and concentrate on analyzing the contents from 38 volumes of Gap Press magazine. To accomplish our goal of study, we first define the concept of sports-inspired fashion and propose a framework of analysis to study hybrid patterns by reviewing the previous studies on hybrid patterns. Second, we analyze a wide range of sports-inspired fashion examples that have appeared in Gap Press magazines for the past 10 years(those which have been inspired by sports uniforms and training wears). Third, we analyze and classify the hybrid patterns of sports-inspired fashion. The results of our research are as follows. We have collected a total of 534 SIF works from the whole set of 61359 pictures and examined 23 sports fields. In terms of seasonal changes, the SIF works were found the most in the spring collections. Then, we have identified 25 hybrid patterns. The time hybrid pattern comprises more than half of the data(58.2%). The class-culture hybrid patterns comprise 18.8%, while the gender hybrid patterns comprise 18.2%. However, the intercultural hybrid patterns were rarely found, comprising merely 5% of the data. Our analysis confirms that sports and sports wear fashion are changing and developing in truly diverse ways in this modern era. This trend has continued to influence the high fashion in the modern age and is expected to exert a continuous impact on the change of fashion in the future.

영진약품 중앙연구소 - 연구소 탐방

  • 정계종
    • The Microorganisms and Industry
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    • v.20 no.2
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    • pp.46-48
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    • 1994
  • The aim of the sutdy is to collect a variety of wild yeasts from different regions in Korea and in different seasons and to account for the natural patterns of regional and seasonal variation that they display. From the specimens collected in this study, more useful strains are expected to be discovered, which can be cultivated and utilized fro industrial development. The study attempts to determine the degree to which utilizable yeasts can be applied in brewing, confectionary, baking, the manufacture of medicine, and as feed yeast. Such findings would contribute not only to the development of academic research, but would also be important in obtaining raw material that can be applied in our daily lives and in industrial development in response to the demands of the times.

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Seasonal Variation in Species Composition and Biomass of Microphytobenthos at Jinsanri, Taean, Korea (한국 태안군 진산리 저서미세조류의 계절별 종조성 및 생물량 변화)

  • Park, Seo Kyoung;Kim, Bo Yeon;Choi, Han Gil;Oh, Joung-Soon;Chung, Sang-Ok;An, Kyoung-Ho;Park, Kwang-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.2
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    • pp.176-185
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    • 2013
  • Seasonal species composition and biomass of microphytobenthos were examined at the intertidal flats of Jinsanri, Taean, Korea, from April to December 2011. In total, 121 species were identified, including 109 diatoms, 5 blue-green algae, and 5 dinoflagellates. Seasonal variation in species number ranged from 49 to 56 species (minimum in October and maximal in April), while vertical variation across three different shore levels ranged from 64 to 77 species with maximum at high and minimum at low shore. Species diversity ranged from 3.22 to 3.42 seasonally and from 3.50 to 3.17 across vertical shore levels. Seasonal average values of the normalized difference vegetation index and the vegetation index were 0.06 and 1.14, respectively. Chlorophyll a concentrations were $66.00-120.73mg/m^2$, with a seasonal minimum and maximum in July and October, respectively, and a vertical shore maximum of $137.35mg/m^2$ at mid shore. Phaeopigment concentrations peaked in October ($50.78mg/m^2$) and at high shore ($61.58mg/m^2$) and were lowest in December ($22.53mg/m^2$) and at low shore ($15.28mg/m^2$). The number of microphytobenthos ranged from 78,556 to 287,898 cells/$cm^2$, reaching a maximum in April and a minimum in July. The diatoms Paralia sulcata, Navicula sp., and Delphines surirella were dominant at all tidal levels over the study period. Dinoflagellates were dominant in July at low shore, and blue-green algae were abundant between July and October at mid shore. In conclusion, species composition and primary production of microphytobenthos exhibited clear seasonal and vertical patterns.

Seasonal Dynamics of Fish Fauna and Compositions in the Gap Stream Along With Conventional Water Quality

  • Lee, Jae-Hoon;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.40 no.4
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    • pp.503-510
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    • 2007
  • The purposes of the study were to analyze the seasonal effects on the fish fauna and compositions including trophic guilds and tolerance guilds. For the study, we collected fish samples twice in June as premonsoon period and early September 2007 as monsoon periods in five sampling sites of the Gap Stream, and then biological oxygen demand (BOD), nutrients (TN, TP) and suspended solids (SS) were compared with the guild data along the gradient of upstream-to-downstream. Chemical water quality, based on BOD, TP, and TN degraded gradually from the upstream to downstream reach and there were about 3 fold difference between S1 and S5. Water quality was worse in the premonsoon than the monsoon, and the heavy monsoon resulted in a dilution of the polluted river by rain water, especially, in the downstream reach. Total number of fish species, based on the catch per unit effort (CPUE), showed a distinct difference between the two seasons; 30 species were sampled in premonsoon, but 23 species were sampled in the monsoon, indicating a seasonal difference in the fish fauna. Tolerant species dominated the fish community (48.3%) in the stream, and the proportions prior to physical disturbance by the monsoon rain were evidently greater in the downstream reach than the upstream. This reflected the characteristics of urban stream polluted by nutrient enrichment as shown in the BOD and TP values. Sensitive species in the premonsoon decreased from the gradient of upstream-to-downstream reach. Such seasonal modifications in the trophic and tolerance guilds were evident. In the analysis of trophic guild and habitat guild, during the premonsoon the proportion of insectivore and riffle-benthic species were largely greater in the upstream reach than the downstream, whereas the proportions were opposite along the gradient of the stream in monsoon. Thus, the patterns of chemical water quality along the longitudinal gradients reflected the premonsoon conditions of insectivores and tolerant species, indicating that summer monsoon data of fish may not match with water quality due to large physical disturbance by flow regime. Seasonal monsoon in this region as well as the chemical pollution may act as a key role influencing the fish compositions of trophic and tolerance guilds and fauna. The data collected during the premonsoon rather than the monsoon, thus, may be better predictor for a diagnosis of stream health conditions.

A Study on High-Resolution Seasonal Variations of Major Ionic Species in Recent Snow Near the Antarctic Jang Bogo Station (남극 장보고과학기지 인근에서 채취한 눈시료 내의 주요 이온성분들의 고해상도 계절변동성 연구)

  • Kwak, Hoje;Kang, Jung-Ho;Hong, Sang-Bum;Lee, Jeonghoon;Chang, Chaewon;Hur, Soon Do;Hong, Sungmin
    • Ocean and Polar Research
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    • v.37 no.2
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    • pp.127-140
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    • 2015
  • A continuous series of 60 snow samples was collected at a 2.5-cm interval from a 1.5-m snow pit at a site on the Styx Glacier Plateau in Victoria Land, Antarctica, during the 2011/2012 austral summer season. Various chemical components (${\delta}D$, ${\delta}^{18}O$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $SO_4{^2-}$, $NO_3{^-}$, $F^-$, $CH_3SO_3{^-}$, $CH_3CO_2{^-}$ and $HCO_2{^-}$) were determined to understand the highly resolved seasonal variations of these species in the coastal atmosphere near the Antarctic Jang Bogo station. Based on vertical profiles of ${\delta}^{18}O$, $NO_3{^-}$and MSA, which showed prominent seasonal changes in concentrations, the snow samples were dated to cover the time period from 2009 austral winter to 2012 austral summer with a mean accumulation rate of $226kgH_2Om^{-2}yr^{-1}$. Our snow profiles show pronounced seasonal variations for all the measured chemical species with a different pattern between different species. The distinctive feature of the occurrence patterns of the seasonal variations is clearly linked to changes in the relative strength of contributions from various natural sources (sea salt spray, volcanoes, crust-derived dust, and marine biogenic activities) during different short-term periods. The results allow us to understand the transport pathways and input mechanisms for each species and provide valuable information that will be useful for investigating long-term (decades to century scale periods) climate and environmental changes that can be deduced from an ice core to be retrieved from the Styx Glacier Plateau in the near future.