• 제목/요약/키워드: Climatic Changes

검색결과 319건 처리시간 0.031초

ENSO가 우리나라 강우의 확률빈도와 공간분포에 미치는 영향 (Assessment of the ENSO Impact on Frequency and Spatial Distribution of Rainfall in South Korea)

  • 김수전;김병식;김형수
    • 한국습지학회지
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    • 제10권2호
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    • pp.143-153
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    • 2008
  • 본 논문의 목적은 ENSO의 영향에 의한 우리나라 강우의 확률빈도와 공간분포 특성을 분석하는 것이다. 따라서 우리나라 기상관측소의 강우량 자료를 Warm(El Nino), Cold(La Nina), Normal 에피소드에 따라 기간별로 분류하였다. 또한 이렇게 분류한 자료는 Markov Chain 모형을 이용하여 100년의 자료로 모의 발생하였고 에피소드별로 빈도분석을 실시하였다. 빈도분석 결과 에피소드에 따라 각 기상관측소별로 강우의 크기에 영향을 미치고 있음을 알 수 있었다. 또한 군집분석을 실시하여 각 에피소드의 공간적인 영향에 대해서 분석하였다. 결과적으로 Warm(El Nino), Cold(La Nina) and Normal 에피소드로 대표되는 ENSO는 우리나라 강우의 확률빈도과 공간분포에 크게 영향을 미치는 것으로 파악되었다.

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대기 $CO_2$의 점증에 따른 대기/해양 접합 모형 지표 기온의 일시적 변동성 분석 (Transient Variations of the Surface Air Temperature Field of a Coupled Atmosphere-Ocean Model to Gradual Changes of Atmospheric $CO_2$)

  • 하경자;하은호
    • 한국환경과학회지
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    • 제7권1호
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    • pp.27-35
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    • 1998
  • The present study intends to investigate the transient response of an atmosphere /ocean general circulation model to a gradual Increase of atmospheric carbon dioxide. To detect the climatic change of the for 1% $CO_2$ run with increasing $CO_2$ and the control run with fried $CO_2$ are compared. From response of the surface air temperature due to the gradual increase of atmospheric carbon dioxide is slowly increased with latitudes and is clearly larger over continents than oceans. The annual goffal mean temperature is continuously increased with 0.03552 per one year with strong SIN ratio and distinguished from the natural variability The time dependent response of the gradual increasing $CO_2$ has the strong seasonal variability with small change In summer and large change in winter, and the strong regional In the Asian and the American continents. It has been suggested that the direct and the feedback processes in the climate systems should be investigated by the detailed sensitivity runs to get the meaninguul estimate of the $CO_2$ forced variability.

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용동굴레와 각시둥글레의 생장특성과 라메트 개체군의 동태 (Growth Characteristics and Demography of Polygonatum involucratum and Polygonatum humile Ramet Population)

  • Choung, Yeon-Sook
    • The Korean Journal of Ecology
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    • 제14권3호
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    • pp.305-316
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    • 1991
  • Growth hadit and demograph in a mature population of polygonatum and polygonatum humile in kanghwa island were studied for two growing seasons. Shoots of two species emerged early spring from the growing apices of the underdground rhizomes which had persisted for up to 1~5 year.after flowering, the ramets produced two rhizome buds at the shoot base. Bacause of the apical dominance in the rhizome system, a new rhizome was developed from only one bud, an actual bud,and the other latent buds were suppressed sothat remained dormant. The latent dud produced a new rhizome only when the actual dud was severed by the herbivores or by the physical obstacles. Therefore, the ramet number is not increased by the new rhizome from the latent bud. however, new ramets dould sometimes grow from latent buds which had been produced more than a year ago. Production of these ramets was main means increasing the ramet numbew and widening the potential zone of exploitation. Changes in size class of each ramet were noyiceable after a tear in small size-classes. Small ramets replaced themselves with larger-sized ramet, while large ramets with similar-sized or smallar-sized ramets. ramet numbers were average 0.82and 1.14 times of those fromthe previous year inp. involucratum and p. humile, though there was between-site variation. Almost all the ramets in the quadrats were alive during the growing season. when the entire rhizome systems were excavater next spring, there were many rhizomesegments without shoots, especially in p. involucratum. therefore, the drcrease of ramet number in p. involucratum in probably due to the climatic factors of winter.

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기상청 기후자료의 균질성 문제 (II): 통계지침의 변경 (Inhomogeneities in Korean Climate Data (II): Due to the Change of the Computing Procedure of Daily Mean)

  • 류상범;김연희
    • 대기
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    • 제17권1호
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    • pp.17-26
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    • 2007
  • The station relocations, the replacement of instruments, and the change of a procedure for calculating derived climatic quantities from observations are well-known nonclimatic factors that seriously contaminate the worthwhile results in climate study. Prior to embarking on the climatological analysis, therefore, the quality and homogeneity of the utilized data sets should be properly evaluated with metadata. According to the metadata of the Korea Meteorological Administration (KMA), there have been plenty of changes in the procedure computing the daily mean values of temperature, humidity, etc, since 1904. For routine climatological work, it is customary to compute approximate daily mean values for individual days from values observed at fixed hours. In the KMA, fixed hours were totally 5 times changed: at four-hourly, four-hourly interval with additional 12 hour, eight-hourly, six-hourly, three-hourly intervals. In this paper, the homogeneity in the daily mean temperature dataset of the KMA was assessed with the consistency and efficiency of point estimators. We used the daily mean calculated from the 24 hourly readings as a potential true value. Approximate daily means computed from temperatures observed at different fixed hours have statistically different properties. So this inhomogeneity in KMA climate data should be kept in mind if you want to analysis secular aspects of Korea climate using this data set.

사무실 근무자의 온열환경에 대한 적응수준 진단 (Diagnosis of Office Occupant's Adaptation Level for Thermal Environment)

  • 김양원
    • 한국생활과학회지
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    • 제12권5호
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    • pp.747-754
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    • 2003
  • The actual clothing conditions were surveyed to diagnose clothing condition of Korean female in the view point of the adaptation to the thermal environment according to seasonal changes. Then, clothing microclimate, physiological responses, and subjective sensation were investigated through wearing trials on human body in climatic chamber based on the results from the survey. Factors to evaluate validity of clothing condition were clothing weight, clothing microclimate, physiological response of human body, and subjective sensation. The results were as follows: 1. Clothing weight per body surface area of the season was $856g/m^{2}$, $439g/m^{2}$ in summer, $630g/m^{2}$ in fall, and $1184g/m^{2}$ in winter. Cold - resistance of Korean female in office was superior to Japanese, inferior to residents of rural areas of Korea, and similar to male in office. However, in heat - resistance, female in office was inferior to residents of rural areas of Korea. 2. In spring, fall, winter, clothing microclimate temperature was a little higher than that in summer. Therefore, it was not a desirable wearing condition even though the clothing microclimate was comfortable zone. 3. Mean skin temperature of female in office was including within the range of Winslow's comfortable zone, but the range of comfortable zone in mean skin temperature of female was more narrow than Winslow's. Thus, it has problem for female to adaptation to thermal environment.

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REMOTELY SENSED INVESTIGATIONS OF FOREST CANOPY DENSITY DYNAMIC IN TROPIC COMBINE WITH LANDSAT AND FIELD MEASUREMENT DATA

  • Panta, Menaka;Kim, Hye-Hyun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.102-105
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    • 2006
  • Forest canopy density is an essentially important for maintaining the diversify flora and fauna in the tropic. But, the natural and human disturbances have an influence over the inconsistency of forest canopy density. So, forest canopy density (FCD) has been threatened in the tropic since a decade. The objective of this study was to examine the dynamics change of the forest canopy density in tropical forest Chitwan, Nepal combine with field survey and remote sensing data. The field survey data of 2001 such as canopy cover percentage, dbh so on and some human disturbances were used. Similarly, Landsat TM 1988 and ETM+ 2001 have also used to predict the dynamic changes of the FCD over the period. Moreover, nonparametric Kruskal- Wallis test has performed for the validation of the results. Data analysis revealed that very few factors i.e. the number of trees, path, and fire had realized statistically significance at P=<0.05. Therefore we concluded that detail analysis could be needed incorporate with additional socioeconomic, climatic, biophysical and institutional factors for the better understanding of the forest canopy dynamic in particular location.

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선운산 지역의 현존식생과 잠재자연식생 (Actual Vegetation and Potential Natural Vegetation of Seonunsan Area, Southwestern Korea)

  • Kim, Jeong-Un;Yang-Jai Yim
    • The Korean Journal of Ecology
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    • 제10권4호
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    • pp.159-164
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    • 1987
  • The potential natural vegetation of Seonunsan area, southwestern Korea, was inferred from the actual vegetation. In previous two papers the plant communities of actual vegetation of the area is grouped into nine types; Quercus variabilis, Pinus densiflora, Carpinus tschonoskii, Quercus serrata, Camellia japonica (plantation), Quercus aliena, Pinus thunbergii, Zelkova serrata and Carpinus laxiflora forest. With the analysis of species richness, age structure and various informations on vegetation changes of the plant communities, two paths of late stage succession are suggested in climatic climax starting from Pinus densiflora forest in the area. One is through Quercus variabilis forest to Carpinus laxiflora forest in upper parts of the mountain and the other through Quercus aliena forest to Carpinus tschonoskii forest in lower parts of the mountain. With analysis of actual vegetation and the examination of informations including human activities in the area, the potential natural vegetation of the area was inferred. The potential natural vegetation of the area was mainly composed of Carpinus laxiflora, Carpinus tschonoskii, Pinus densiflora and Zelkova serrata forest. The actual vegetation map and potential natural vegetation map (scale, 1:25, 000) and other results from this study might be the useful data for the protection of natural vegetation and restoration of the current vegetation.

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High altitude powered lighter-than-air vehicle as remote sensing platform

  • Onda, Masahiko
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.1361-1364
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    • 1990
  • In order to tackle global environmental problems such as destruction of the ozone layer or climatic changes due to atmospheric temperature increase, the acquisition of plentiful and precise data is necessary. Therefore, a means of conducting long-lasting high-resolution measurements over broad areas is required. A feasibility study has been made on a high altitude (20km), super-pressured helium-filled PLTA (Powered Ligher-than-Air) vehicle as an ideal platform for environmental observation. It has a long service life and carries a larger payload than an artificial satellite. This PLTA platform uses an electric propulsion system to maintain position in space against wind currents. The thruster is driven by solar power acquired from solar cells. For night use, solar energy is stored in regenerative fuel cells. This study focuses on energy balance and structural analysis of the hull and platform. The platform is capable of conducting high resolution remote sensing as well as having the capability to serve as a telecommunications relay. The platform could replace a number of ground-based telecommunications relay facilities, guaranteeing sufficient radio frequency intensity to secure good quality telecommunication transmittal. The altitude at which the platform resides has the lowest wind flow in the lower stratosphere, and permits viewing from the ground within a 1,000km range. Because this altitude is much lower than that required of an artificial satellite, the measuring resolution is a couple of thousand times higher than with artificial satellites. The platform can also be used to chase typhoons and observe them from their sources in tropical regions.

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Plasticity of rice to water extremes: Farmers' genes to mechanisms

  • Bailey-Serres, Julia
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.5-5
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    • 2017
  • Too little and too much water due to climatic events is a significant cause of global food insecurity. Crops are less productive under water-limited conditions and all major crops, with the exception of rice (Oryza sativa), die within a few days of complete submergence. To complement our studies on genes such as SUB1A, (an ERF-VII transcription factor that provides robust submergence tolerance) and AG1 (a TREHALOSE 6-P PHOSPHATASE that promotes establishment of young seedlings underwater), we have retooled INTACT (${\underline{I}}solation$ of ${\underline{N}}uclei$ ${\underline{TA}}gged$ in specific ${\underline{C}}ell$ ${\underline{T}}ypes$) and TRAP (${\underline{T}}ranslating$ ${\underline{R}}ibosome$ ${\underline{A}}ffinity$ ${\underline{P}}urification$) for rice. These technologies enable us to follow dynamics in chromatin, nuclear pre-mRNAs and ribosome-bound mRNAs in meristems and diverse cell types. With these technologies we can better interpret responses to stresses and reestablishment of homeostasis. These include stress acclimation strategies involving changes in metabolism and development, such as dynamics in suberin deposition in sub-epidermal layers of roots that limit water loss under drought and oxygen escape during waterlogging. Our new data uncover dynamic and reversible regulation at multiple levels of gene regulation and provide new insights into processes of stress resilience. Supported by US NSF-PGRP Plasticity (IOS-1238243), Secretome (IOS-1546879) and REU (DBI-146129) grants.

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N-Nitrosodimethylamine in the Kashmiri Diet and Possible Roles in the High Incidence of Gastrointestinal Cancers

  • Chikan, Naveed A.;Shabir, Nadeem;Shaffi, Sheikh;Mir, Manzoor R.;Patel, Trupti N.
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권3호
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    • pp.1077-1079
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    • 2012
  • The Kashmiri population is culturally distinct with special dietary features owing to the temperate climatic conditions of Kashmir valley. This has habituated the population to preserve food in smoked, pickled and sundried forms which include considerable amounts of $N$-nitroso compounds (NOCs). These are known to cause cytotoxicity, DNA damage, mutation, unscheduled DNA synthesis and DNA methylation. All of these changes at molecular level are known to contribute to the pathogenesis of cancer. One of the prominent NOCs found in Kashmiri food is $N$-Nitrosodimethylamine (NDMA). Here we review the occurrence of NDMA in sundried foods, dried fish, kehwa, traditional pickle, $Brassica$ $oleracia$ and $tobbaco$. We also discuss its possible role in the high prevalence of gastrointestinal cancers in Kashmir.