• Title/Summary/Keyword: Warm pool

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A multi-scale analysis of the interdecadal change in the Madden-Julian Oscillation (MJO의 다중스케일 분석을 통한 수십년 변동성)

  • Lee, Sang-Heon;Seo, Kyong-Hwan
    • Atmosphere
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    • v.21 no.2
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    • pp.143-149
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    • 2011
  • A new multi-timescale analysis method, Ensemble Empirical Mode Decomposition (EEMD), is used to diagnose the variation of the MJO activity determined by 850hPa and 200hPa zonal winds from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis data for the 56-yr period from 1950 to 2005. The results show that MJO activity can be decomposed into 9 quasi-periodic oscillations and a trend. With each level of contribution of the quasi-periodic oscillation discussed, the bi-seasonal oscillation, the interannual oscillation and the trend of the MJO activity are the most prominent features. The trend increases almost linearly, so that prior to around 1978 the activity of the MJO is lower than that during the latter part. This may be related to the tropical sea surface temperature(SST). It is speculated that the interdecadal change in the MJO activity appeared in around 1978 is related to the warmer SST in the equatorial warm pool, especially over the Indian Ocean.

Characteristics of the Gross Moist Stability in the Tropics and Its Future Change (열대 지역 Gross Moist Stability 특징 분석 및 미래 변화)

  • Kim, Hye-Won;Seo, Kyong-Hwan
    • Atmosphere
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    • v.24 no.2
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    • pp.141-150
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    • 2014
  • This study investigates the characteristics of the Gross Moist Stability (GMS) over the tropics. The GMS summarizes the relationship between large-scale entropy forcing due to radiation and surface fluxes and the response of smaller-scale convection. The GMS is able to explain both to where moist entropy is advected by the atmospheric circulation and how deep the moisture flux convergence is in the tropical region. In the deep convective region, positive GMS appears over the warm pool region due to the strong column-integrated moisture convergence and the ensuing export of moist entropy to the environment. The vertical advection of moist entropy dominates over the horizontal advection in this region. Meanwhile, over the eastern tropical ITCZ region, which is characterized by shallow convective area, import of moist entropy by horizontal winds is dominant compared to the vertical moist entropy advection. Future changes in the GMS are also examined using the 22 CMIP5 model simulations. A decrease in the GMS appears widely across the tropics, but its increase occurs over the western-central equatorial Pacific. It is evident that the increased GMS region corresponds to an increased region of precipitation, implying that strengthened convection in the future due to increased entropy forcing exports the enhanced moist energy to stabilize the environment.

Assessment of Teleconnection based Long-Range Flood Risk Prediction during different El Ni?o phases: A Case Study of Gyeongnam (원격상관기반 엘니뇨 시기별 홍수위험 장기예측 평가: 경남지자체 대상)

  • Yoon, Sun-Kwon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.91-91
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    • 2016
  • 본 연구는 대규모 대기환경패턴 변화에 따른 극한 기후발생 및 극치 수문사상의 지역적 변동 특성을 분석하였고, 통계기법을 이용한 기후지수와 수문변량간의 원격상관관계 분석결과를 이용하여 한반도 중 장기 수문변량 예측의 가능성을 진단하였다. 또한 경남 지자체를 대상으로 다양한 통계예측모형(AR, MA, ARMA, ARIMA, VAR)을 구축하여 그 예측능력을 평가하고 적용성을 검토하였고, 중 장기 통합홍수위험 평가를 위한 인덱스를 개발하였다. 서로 다른 엘니뇨 시기별 홍수 위험도 평가결과 전형적인 엘니뇨(Cold Tongue El Nino)해에는 남해안 일부 지역(거제시, 남해군)에서 위험도가 높게 산정되었으며, 경남 북부지역에서는 위험도가 매우 낮게 산정되었다. 중앙태평양 엘니뇨(Warm Pool El Nino) 해에는 경남 남부 지역을 중심으로 홍수위험지수가 높게 나타나 중앙태평양 엘니뇨가 발달 시 경남지역의 홍수위험 발생 가능성 평년에 비하여 큰 것으로 분석된다. 또한 라니냐(La Nina) 해에는 경남 서쪽일부 지역(남해군, 하동군, 산청군)에서 통합홍수위험지수가 높게 나타났으며, 나머지 지역에서는 홍수위험도가 작거나 중간 값을 보이는 것으로 분석되었다. 본 연구는 중 장기적 관점에서 수자원 예측 및 효율적인 물 관리와 안정적인 용수공급에 도움을 줄 것으로 사료되며, 한반도 대상 특정 엘니뇨 해의 지자체별 홍수위험 취약성 평가에 활용이 가능할 것이다.

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An Analysis of a 100-Years-Old Map of the Heritage Trees in Jeju Island (제주도 노거수 자연유산의 100년 전과 현재 분석)

  • Song, Kuk-Man;Kim, Yang-Ji;Seo, Yeon-Ok;Choi, Hyung-Soon;Choi, Byoung-Ki
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.2
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    • pp.20-29
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    • 2019
  • The purpose of this study is to verify and reconstruct the record information for big old trees of Jeju on the basis of the precise map of Jeju island in 1918 which was produced 100 years ago. For the analysis of high altitude, coordinate system and georeferencing were performed by selecting representative points using ArcGIS. We extracted digitized information by using point extraction method and extracted attribute information based on legend type and relative size in map. Based on the map of the past 100 years ago, the present situation of the big old tree in Jeju was analyzed and their characteristics were analyzed. In addition, based on the information of the protected big old trees in present, we discussed the characteristics of past tree (1918), present tree (2019), and contribution of big old tree in Jeju landscape and vegetation. As a result, 1,013 individuals were distributed in Jeju Island 100 years ago. Even when it was intensive in the use of timber, the big old trees were protected, and contributed as a representative component of Jeju's unique landscape. The remaining distribution of Jeju's big old tree is 159 trees. As in the past, distribution has been confirmed around the lowlands, but declines in numbers are found throughout the island. The major factors for the decline of individuals are large-scale development projects such as reaching the limit of life, natural disturbance (typhoon, disease, pest, drought, etc.). However, it is presumed that a large number of individuals have played a leading role in shaping the current forests as contributing to important species sources in the restoration process of Jeju vegetation. However, it is presumed that a large number of individuals (405) have played a leading role in forming the present forest by contributing to the species pool in the restoration process of Jeju vegetation.

Modelling Analysis of Climate and Soil Depth Effects on Pine Tree Dieback in Korea Using BIOME-BGC (BIOME-BGC 모형을 이용한 국내 소나무 고사의 기후 및 토심 영향 분석)

  • Kang, Sinkyu;Lim, Jong-Hwan;Kim, Eun-Sook;Cho, Nanghyun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.242-252
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    • 2016
  • A process-based ecosystem model, BIOME-BGC, was applied to simulate seasonal and inter-annual dynamics of carbon and water processes for potential evergreen needleleaf forest (ENF) biome in Korea. Two simulation sites, Milyang and Unljin, were selected to reflect warm-and-dry and cool-and-wet climate regimes, where massive diebacks of pines including Pinus densiflora, P. koraiensis and P thunbergii, were observed in 2009 and 2014, respectively. Standard Precipitation Index (SPI) showed periodic drought occurrence at every 5 years or so for both sites. Since mid-2000s, droughts occurred with hotter climate condition. Among many model variables, Cpool (i.e., a temporary carbon pool reserving photosynthetic compounds before allocations for new tissue production) was identified as a useful proxy variable of tree carbon starvation caused by reduction of gross primary production (GPP) and/or increase of maintenance respiration (Rm). Temporal Cpool variation agreed well with timings of pine tree diebacks for both sites. Though water stress was important, winter- and spring-time warmer temperature also played critical roles in reduction of Cpool, especially for the cool-and-wet Uljin. Shallow soil depth intensified the drought effect, which was, however, marginal for soil depth shallower than 0.5 m. Our modeling analysis implicates seasonal drought and warmer climate can intensify vulnerability of ENF dieback in Korea, especially for shallower soils, in which multi-year continued stress is of concern more than short-term episodic stress.

Latitudinal Variation of Nutritional Condition and Diet for Copepod Species, Euchaeta sp. and Pleuromamma spp., from the Northwest Pacific Ocean Using Lipid Biomarkers (지방 바이오마커를 활용한 북서태평양에서 요각류(Euchaeta sp. and Pleuromamma spp.)의 서식 위도별 영양상태 및 먹이원 연구)

  • Ju, Se-Jong;Ko, Ah-Ra;Lee, Chang-Rae
    • Ocean and Polar Research
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    • v.33 no.spc3
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    • pp.349-358
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    • 2011
  • In order to ascertain latitudinal variation of lipid contents and compositions in copepods, we collected warm water copepod species (Euchaeta sp. and Pleuromamma spp.) from four different regions from low (sub-tropical) to mid (temperate) latitudes in the Northwest Pacific Ocean. Total lipid contents of Pleuromamma spp. were about 11 $ug{\cdot}ind^{-1}$ with little latitudinal variation, whereas Euchaeta sp. showed slightly higher lipid content (20 $ug{\cdot}ind^{-1}$) than Pleuromamma spp. with latitudinal gradient (low at subtropic and high at temperate). Wax esters, known as the major storage lipid classes, were found to be the dominant lipid classes (accounting for more than 35% of total lipids) in Euchaeta sp., whereas in Pleuromamma spp., phospholipids, known as cellular membrane components, were the dominant lipid classes. However, the exception was specimens from warm pool region exhibiting dominance in storage of lipids as a form of triacylglycerols. Among fatty acids, polyunsaturated fatty acids (PUFA), especially docosahexaenoic acid (DHA : 22:6(n-3)) (about 35% of total fatty acids), were most abundant in Euchaeta sp., while saturated fatty acids (SAFA), specially hexadecanoic acid (16:0) (about 30% of total fatty acids), were most abundant in Pleuromamma spp.. Among the neutral fraction of lipids, phytol, originated from the side chain of chlorophyll, was found in all samples which generally indicate active copepods feeding on algae. While only trace amounts of short-chain fatty alcohols were found in Pleuromamma spp., significant amounts of fatty alcohols were found in Euchaeta sp.. Particularly, significant amounts of long chain monounsaturated fatty alcohols (20:1 and 22:1), generally found in cold water species, were found in Euchaeta sp. from low latitudes. The latitudinal variation of trophic lipid markers in these copepods could be significantly related with in-situ food availability and species-specific diet preference. The result of this study suggests that the lipid contents and compositions in copepods may not only indicate their nutritional condition and feeding ecology but also provide insight into species-specific living strategies under different environmental conditions (i.e. water temperature, food availability).

TIPEX (Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment) Program (태평양-인도양 해양순환 연구 프로그램)

  • Jeon, Dongchull;Kim, Eung;Shin, Chang Woong;Kim, Cheol-Ho;Kug, Jong Seong;Lee, Jae Hak;Lee, Youn-Ho;Kim, Suk Hyun
    • Ocean and Polar Research
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    • v.35 no.3
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    • pp.259-272
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    • 2013
  • One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The 'Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX)' is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1) to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2) to understand the large-scale oceanic-climatic variation including El Nino-Southern Oscillation (ENSO)/Warm Pool/Pacific Decadal Oscillation (PDO)/Indian Ocean Dipole (IOD), and 3) to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.

A Survey of the Role of Thalassotherapy Program in SPA Salon (스파살롱내 딸라소테라피 프로그램에 대한 연구)

  • Hong, Ran-Hi;Heo, Eun-Young
    • Journal of the Korean Society of Fashion and Beauty
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    • v.4 no.1 s.7
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    • pp.51-59
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    • 2006
  • Today, SPA fills many of the same needs as they did thousands of years ago, including relaxation, wellness and stress relief by incorporating many of the same methods embraced by the ancients such as a multitude of hydrotherapy treatments, thalassotherapy and massage therapy, one of the most widely used SPA treatments. The definition is as follows: SPA is entities devoted to enhancing overall well-being through a variety of professional services that encourage the renewal of mind, body and spirit. It was from here that the concept of modernday SPA evolved, incorporating full health and beauty services along with sport, aquatic and rest facilities. Todays SPA, a absolute concept, is being specialized and spread as fast as undefinable just in a word. Thalassotherapy, a kind of SPA therapy, contains minerals and trace elements. Born more than 4,000 years ago in ancient Egypt, thalassotherapy comes from the Greek words for thalasso(sea water) and therapeia(to heal). Thalassa was the Greek personification of the Mediterranean Sea that surrounded them and gave them so much of their sustenance. It helps to nourish, hydrate and refine skin texture and also eliminate metabolic waste and toxins in the body. Thalassotherapy is recommended for post-natal and postsurgery recovery period, chronic fatigue, circulatory problems, cellulite control and dermatological problems. It's also possible to enjoy the thalassotherapy SPA as a day guest. Be sure to try the jansu massage, given in the heated sea water pool. As a trained therapist gently whisks clients through the womb-warm water, clients can practically feel the toxins leave their body. Many women from all over the world have been kept up beautiful skin with applying thalassotherapy to their faces and bodies since long times and these days in France, they are getting great curative clinical effects from renovative and scientific technological combination. Thus thalassotherapy will be absolutely ultimate form of natural healing which can keep and recover human's health and beauty.

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Analysis of An Outflow Boundary Induced Heavy Rainfall That Occurred in the Seoul Metropolitan Area (수도권에서 유출류 경계(Outflow Boundary)를 따라 발생한 집중호우 분석)

  • Lee, Ji-Won;Min, Ki-Hong
    • Atmosphere
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    • v.27 no.4
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    • pp.455-466
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    • 2017
  • In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.

Spatial Variability of Surface fCO2 in the Western North Pacific during Summer 2007 (2007년 여름 북서태평양 이산화탄소 분압의 공간 변동성)

  • Choi, Sang-Hwa;Kim, Dong-Seon;Kim, Kyung-Hee;Min, Hong-Sik
    • Ocean and Polar Research
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    • v.30 no.3
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    • pp.335-345
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    • 2008
  • In order to study spatial variabilities and major controlling factors, we measured fugacity of $CO_2(fCO_2)$, temperature, salinity and nutrients in surface waters of the North Pacific($7^{\circ}30'{\sim}33^{\circ}15'N$, $123^{\circ}56'E{\sim}164^{\circ}24'W$) between September$\sim$October 2007. The North Pacific and the marginal sea were distinguished by $fCO_2$ distribution as well as unique characteristics of temperature and salinity. There was a distinct diurnal SST variation in the tropical North Pacific area, and surface $fCO_2$ coincidently showed diurnal variation. In the North Pacific area, surface $fCO_2$ was mainly controlled by temperature, while in the marginal sea area it was primarily dependent on alkalinity and dissolved inorganic carbon concentrations. Air-sea $CO_2$ flux showed a large spatial variation, with a range of $-6.10{\sim}5.06\;mmol\;m^{-2}day^{-1}$. The center of subtropical gyre of North Pacific acted as a source of $CO_2(3.09{\pm}0.95\;mmol\;m^{-2}day^{-1})$. Tropical western North Pacific (i.e. the 'warm pool' area and the subtropical western North Pacific) acted as weak sources of $CO_2$($1.07{\pm}1.20\;mmol\;m^{-2}day^{-1}$ and $0.50{\pm}0.53\;mmol\;m^{-2}day^{-1}$, respectively). In the marginal sea, however, the flux was estimated to be $-0.68{\pm}1.17\;mmol\;m^{-2}day^{-1}$, indicating that this area acted as a sink for $CO_2$.