• Title/Summary/Keyword: Climate Variability Index

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Projection of Future Changes in Drought Characteristics in Korea Peninsula Using Effective Drought Index (유효가뭄지수(EDI)를 이용한 한반도 미래 가뭄 특성 전망)

  • Gwak, Yongseok;Cho, Jaepil;Jung, Imgook;Kim, Dowoo;Jang, Sangmin
    • Journal of Climate Change Research
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    • v.9 no.1
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    • pp.31-45
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    • 2018
  • This study implemented the prediction of drought properties (number of drought events, intensity, duration) using the user-oriented systematical procedures of downscaling climate change scenarios based the multiple global climate models (GCMs), AIMS (APCC Integrated Modeling Solution) program. The drought properties were defined and estimated with Effective Drought Index (EDI). The optimal 10 models among 29 GCMs were selected, by the estimation of the spatial and temporal reproducibility about the five climate change indices related with precipitation. In addition, Simple Quantile Mapping (SQM) as the downscaling technique is much better in describing the observed precipitation events than Spatial Disaggregation Quantile Delta Mapping (SDQDM). Even though the procedure was systematically applied, there are still limitations in describing the observed spatial precipitation properties well due to the offset of spatial variability in multi-model ensemble (MME) analysis. As a result, the farther into the future, the duration and the number of drought generation will be decreased, while the intensity of drought will be increased. Regionally, the drought at the central regions of the Korean Peninsula is expected to be mitigated, while that at the southern regions are expected to be severe.

Can Agricultural Aid and Remittances Alleviate Macroeconomic Volatility in Response to Climate Change Shocks? (아프리카 국가들의 경제성장률 변동성에 기후변화, 송금 및 농업 원조가 미치는 영향 분석)

  • You, Soobin;Kim, Taeyoon
    • Environmental and Resource Economics Review
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    • v.25 no.4
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    • pp.471-494
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    • 2016
  • This study investigates the effect of remittance and agricultural aid inflows on GDP growth rate volatility in response to climate change shocks in twenty-eight African countries by using system generalized method of moments from 1996 to 2013 with three years grouped data. The climate change shocks are indicated by four variables; natural disasters, rainfall variability, fluctuation in temperature and the weighted anomaly standardized precipitation (WASP) index. Consequently, natural disasters and temperature variability have a significant effect on GDP volatility, while rainfall variability and WASP index have no adverse consequence on stabilization of the economy. On the other hand, in general, remittances and agricultural aid are helpful to stabilize the economy and especially remittances inflows can play a crucial role as insurance when natural disasters occur.

Review of Trends in Recent Climate Research by Korean Climatologists (최근 한국의 기후학 연구 동향)

  • Lee, Eun-Gul;Lee, Kyoung-Mi;Lee, Seung-Ho
    • Journal of the Korean Geographical Society
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    • v.47 no.4
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    • pp.490-513
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    • 2012
  • This study reviewed recent trends in climate research by Korean climatologists. We analyzed six domestic journals listed in the Korean Citation Index and four international journals listed in the Science Citation Index during 2001-2011. Research on climate change has rapidly increased during the study period and studies on precipitation variability have been given continual attentions among Korean climatologists. In climate change research, meteorologists focused on characteristics, prediction, and causes while geographers were more interested in characteristics and impacts of climate change. In applied climatology and bioclimatology, research on the impacts of climate change on agriculture, livestock, vegetation, and human health has increased under recent climate change. While there has been steady interest in climatography by Korean climatologists, the number of papers has generally decreased over the recent period.

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An Investigation of Large-Scale Climate Indices with the influence on Temperature and Precipitation Variation in Korea (한반도 기온 및 강수량 변동에 영향을 미치는 광역규모 기후지수들에 대한 고찰)

  • Kim, Yeon-Hee;Kim, Maeng-Ki;Lee, Woo-Seop
    • Atmosphere
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    • v.18 no.2
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    • pp.83-95
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    • 2008
  • In this study we have investigated the preceding eighteen large-scale climate indices with a lead time from zero to twelve months that have an influence on the variability of temperature and precipitation in Korea in order to understand which climate indices are overall available as predictors for long-range forecasting. We also have studied the dynamic link between preceding large-scale climate indices and regional climate using singular value decomposition analysis (SVDA) and correlation analysis (CA). Based on the coupled mode between large-scale circulation and regional climate, and correlation pattern between the preceding large-scale climate indices and large-scale circulation, the level of significance on climate indices as a predictor for monthly mean temperature and precipitation was evaluated for 5 and 1% level.

Application of Artificial Neural Network Ensemble Model Considering Long-term Climate Variability: Case Study of Dam Inflow Forecasting in Han-River Basin (장기 기후 변동성을 고려한 인공신경망 앙상블 모형 적용: 한강 유역 댐 유입량 예측을 중심으로)

  • Kim, Taereem;Joo, Kyungwon;Cho, Wanhee;Heo, Jun-Haeng
    • Journal of Wetlands Research
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    • v.21 no.spc
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    • pp.61-68
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    • 2019
  • Recently, climate indices represented by quantifying atmospheric-ocean circulation patterns have been widely used to predict hydrologic variables for considering long-term climate variability. Hydrologic forecasting models based on artificial neural networks have been developed to provide accurate and stable forecasting performance. Forecasts of hydrologic variables considering climate variability can be effectively used for long-term management of water resources and environmental preservation. Therefore, identifying significant indicators for hydrologic variables and applying forecasting models still remains as a challenge. In this study, we selected representative climate indices that have significant relationships with dam inflow time series in the Han-River basin, South Korea for applying the dam inflow forecasting model. For this purpose, the ensemble empirical mode decomposition(EEMD) method was used to identify a significance between dam inflow and climate indices and an artificial neural network(ANN) ensemble model was applied to overcome the limitation of a single ANN model. As a result, the forecasting performances showed that the mean correlation coefficient of the five dams in the training period is 0.88, and the test period is 0.68. It can be expected to come out various applications using the relationship between hydrologic variables and climate variability in South Korea.

Temperature Variabilities at Upper Layer in the Korean Marine Waters Related to Climate Regime Shifts in the North Pacific (한국주변해역 상층부의 수온 변동과 북태평양 기후체제와의 관계)

  • Rahman, SM M.;Lee, Chung Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.1
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    • pp.145-151
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    • 2016
  • Temperature variability at the upper layer related to climate regime shifts in the Korean waters was illustrated using water temperature, climate index. Three major climate regime shifts (CRS) in 1976, 1988 and 1998 in north Pacific region had an significant influence on the major marine ecosystems structure pattern. Three marginal seas around Korean peninsula; East Sea, East China Sea and Yellow Sea also got important impact from this kind of decadal shift. We used 10m sea water temperatures in four regions of Korean waters since 1950 to detect major fluctuation patterns both seasonally and also decadal shift. 1988 CRS was occurred in all of the study areas in most seasons however, 1998 CRS was only detected in the Yellow Sea and in the southern part of the East Sea. 1976 CRS was detected in all of the study area mainly in winter. After 1998 CRS, the water temperature in the southern part of the East Sea, East China Sea and Yellow Sea were going into decreased pattern; however, in the northern part of the East Sea, it was further shifted to increasing pattern which was started from 1988 CRS period.

Comparative Evaluation of Reproducibility for Spatio-temporal Rainfall Distribution Downscaled Using Different Statistical Methods (통계적 공간상세화 기법의 시공간적 강우분포 재현성 비교평가)

  • Jung, Imgook;Hwang, Syewoon;Cho, Jaepil
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.1
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    • pp.1-13
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    • 2023
  • Various techniques for bias correction and statistical downscaling have been developed to overcome the limitations related to the spatial and temporal resolution and error of climate change scenario data required in various applied research fields including agriculture and water resources. In this study, the characteristics of three different statistical dowscaling methods (i.e., SQM, SDQDM, and BCSA) provided by AIMS were summarized, and climate change scenarios produced by applying each method were comparatively evaluated. In order to compare the average rainfall characteristics of the past period, an index representing the average rainfall characteristics was used, and the reproducibility of extreme weather conditions was evaluated through the abnormal climate-related index. The reproducibility comparison of spatial distribution and variability was compared through variogram and pattern identification of spatial distribution using the average value of the index of the past period. For temporal reproducibility comparison, the raw data and each detailing technique were compared using the transition probability. The results of the study are presented by quantitatively evaluating the strengths and weaknesses of each method. Through comparison of statistical techniques, we expect that the strengths and weaknesses of each detailing technique can be represented, and the most appropriate statistical detailing technique can be advised for the relevant research.

Spring Forest-Fire Variability over Korea Associated with Large-Scale Climate Factors (대규모 기후인자와 관련된 우리나라 봄철 산불위험도 변동)

  • Jeong, Ji-Yoon;Woo, Sung-Ho;Son, Rack-Hun;Yoon, Jin-Ho;Jeong, Jee-Hoon;Lee, Suk-Jun;Lee, Byung-Doo
    • Atmosphere
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    • v.28 no.4
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    • pp.457-467
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    • 2018
  • This study investigated the variability of spring (March-May) forest fire risk in Korea for the period 1991~2017 and analyzed its relationship with large-scale climate factors. The Forest Weather Index (FWI) representing the meteorological risk for forest fire occurrences calculated based on observational data and its relationship with large-scale climate factors were analyzed. We performed the empirical orthogonal function (EOF) analysis on the spring FWI. The leading EOF mode of FWI accounting for about 70% of total variability was found to be highly correlated with total number of forest fire occurrences in Korea. The high FWI, forest fire occurrence risk, in Korea, is associated with warmer atmosphere temperature in midwest Eurasia-China-Korea peninsula, cyclonic circulation anomaly in northeastern China-Korea peninsula-northwest pacific, westerly wind anomaly in central China-Korea peninsula, and low humidity in Korea. These are further related with warmer sea surface temperature and enhanced outgoing longwave radiation over Western Pacific, which represents a typical condition for a La $Ni\tilde{n}a$ episode. This suggests that large-scale climate factors over East Asia and ENSO could have a significant influence on the occurrence of spring forest fires in Korea.

Assessment of 6-Month Lead Prediction Skill of the GloSea5 Hindcast Experiment (GloSea5 모형의 6개월 장기 기후 예측성 검증)

  • Jung, Myung-Il;Son, Seok-Woo;Choi, Jung;Kang, Hyun-Suk
    • Atmosphere
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    • v.25 no.2
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    • pp.323-337
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    • 2015
  • This study explores the 6-month lead prediction skill of several climate indices that influence on East Asian climate in the GloSea5 hindcast experiment. Such indices include Nino3.4, Indian Ocean Diploe (IOD), Arctic Oscillation (AO), various summer and winter Asian monsoon indices. The model's prediction skill of these indices is evaluated by computing the anomaly correlation coefficient (ACC) and mean squared skill score (MSSS) for ensemble mean values over the period of 1996~2009. In general, climate indices that have low seasonal variability are predicted well. For example, in terms of ACC, Nino3.4 index is predicted well at least 6 months in advance. The IOD index is also well predicted in late summer and autumn. This contrasts with the prediction skill of AO index which shows essentially no skill beyond a few months except in February and August. Both summer and winter Asian monsoon indices are also poorly predicted. An exception is the Western North Pacific Monsoon (WNPM) index that exhibits a prediction skill up to 4- to 6-month lead time. However, when MSSS is considered, most climate indices, except Nino3.4 index, show a negligible prediction skill, indicating that conditional bias is significant in the model. These results are only weakly sensitive to the number of ensemble members.

Projected Future Extreme Droughts Based on CMIP6 GCMs under SSP Scenarios (SSP 시나리오에 따른 CMIP6 GCM 기반 미래 극한 가뭄 전망)

  • Kim, Song-Hyun;Nam, Won-Ho;Jeon, Min-Gi;Hong, Eun-Mi;Oh, Chansung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.66 no.4
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    • pp.1-15
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    • 2024
  • In recent years, climate change has been responsible for unusual weather patterns on a global scale. Droughts, natural disasters triggered by insufficient rainfall, can inflict significant social and economic consequences on the entire agricultural sector due to their widespread occurrence and the challenge in accurately predicting their onset. The frequency of drought occurrences in South Korea has been rapidly increasing since 2000, with notably severe droughts hitting regions such as Incheon, Gyeonggi, Gangwon, Chungbuk, and Gyeongbuk in 2015, resulting in significant agricultural and social damage. To prepare for future drought occurrences resulting from climate change, it is essential to develop long-term drought predictions and implement corresponding measures for areas prone to drought. The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report outlines a climate change scenario under the Shared Socioeconomic Pathways (SSPs), which integrates projected future socio-economic changes and climate change mitigation efforts derived from the Coupled Model Intercomparison Project 6 (CMIP6). SSPs encompass a range of factors including demographics, economic development, ecosystems, institutions, technological advancements, and policy frameworks. In this study, various drought indices were calculated using SSP scenarios derived from 18 CMIP6 global climate models. The SSP5-8.5 scenario was employed as the climate change scenario, and meteorological drought indices such as the Standardized Precipitation Index (SPI), Self-Calibrating Effective Drought Index (scEDI), and Standardized Precipitation Evapotranspiration Index (SPEI) were utilized to analyze the prediction and variability of future drought occurrences in South Korea.