https://repository.kopri.re.kr/handle/201206/5459 Thu, 23 Apr 2026 06:20:25 GMT 2026-04-23T06:20:25Z https://repository.kopri.re.kr/handle/201206/5973 Title: Impact of Snow Depth Initialization on Seasonal Prediction of Surface Air Temperature over East Asia for Winter Season Authors: Kim, Seong-Joong; Woo, Sung-Ho; Kim, Baek-Min; Jeong, Jee-Hoon Abstract: Does snow depth initialization have a quantitative impact on sub-seasonal to seasonal prediction skill? To answer this question, a snow depth initialization technique for seasonal forecast system has been implemented and the impact of the initialization on the seasonal forecast of surface air temperature during the wintertime is examined. Since the snow depth observation can not be directly used in the model simulation due to the large systematic bias and much smaller model variability, an anomaly rescaling method to the snow depth initialization is applied. Snow depth in the model is initialized by adding a rescaled snow depth observation anomaly to the model snow depth climatology. A suite of seasonal forecast is performed for each year in recent 12 years (1999-2010) with and without the snow depth initialization to evaluate the performance of the developed technique. The results show that the seasonal forecast of surface air temperature over East Asian region sensitively depends on the initial snow depth anomaly over the region. However, the sensitivity shows large differences for different timing of the initialization and forecast lead time. Especially, the snow depth anomaly initialized in the late winter (Mar. 1) is the most effective in modulating the surface air temperature anomaly after one month. The real predictability gained by the snow depth initialization is also examined from the comparison with observation. The gain of the real predictability is generally small except for the forecasting experiment in the early winter (Nov.1), which shows some skillful forecasts. Implications of these results and future directions for further development are discussed. Sun, 01 Jan 2012 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5973 2012-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5675 Title: A comparison between a Monte Carlo implementation of retrospective optimal interpolation and an ensemble Kalman filter in nonlinear dynamics Authors: Hyo-Jong Song; Kim, Baek-Min; Gyu-Ho Lim Abstract: To more correctly estimate the error covariance of an evolved state of a nonlinear dynamical System, the second and higher-order moments of the prior error need to be known. Analogous to the extension of a Kalman filter into an EnKF, an ensemble retrospective optimalinterpolation (EnROI) technique was derived using the Monte Carlo method from ROI. In contrast to the deterministic version of ROI, the background error covariance is represented by a background ensemble in EnROI. By sequentially applying EnROI to a moving limited analysis window and exploiting the forecast from the average of the background ensemble of En-ROI as a guess field, the computation costs for EnROI can be reduced.nKF, an ensemble retrospective optimalinterpolation (EnROI) technique was derived using the Monte Carlo method from ROI. In contrast to the deterministic version of ROI, the background error covariance is represented by a background ensemble in EnROI. By sequentially applying EnROI to a moving limited analysis window and exploiting the forecast from the average of the background ensemble of En-ROI as a guess field, the computation costs for EnROI can be reduced. Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5675 2011-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5663 Title: Greening in the circumpolar high-latitude may amplify warming in the growing season Authors: Deliang Chen; Jee-Hoon Jeong; David Rayner; Ho, Chang-Hoi; Hans Linderholm; Seung-Ki Min; Kim, Baek-Min; Jong-Seong Kug; Sang-Yoon Jun Abstract: We present a study that suggests greening in the circumpolar high-latitude regions ampli？es surface warming in the growing season (May？September) under enhanced greenhouse conditions. The investigation used a series of climate simulations with the Community Atmospheric Model version 3―which incorporates a coupled, dynamic global vegetation model―with and without vegetation feedback, under both present and doubled CO2 concentrations. Results indicate that climate warming and associated changes promote circumpolar greening with northward expansion and enhanced greenness of both the Arctic tundra and boreal forest regions. This leads to additional surface warming in the Arctic region.f climate simulations with the Community Atmospheric Model version 3―which incorporates a coupled, dynamic global vegetation model―with and without vegetation feedback, under both present and doubled CO2 concentrations. Results indicate that climate warming and associated changes promote circumpolar greening with northward expansion and enhanced greenness of both the Arctic tundra and boreal forest regions. This leads to additional surface warming in the Arctic region. Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5663 2011-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5662 Title: Recent and future sea surface temperature trends in tropical pacific warm pool and cold tongue regions Authors: Ji-Won Kim; Ah, Soon-Il; Jae-Heung Park; Kim, Baek-Min; Seul-Hee Im Abstract: 미래기후에서 적도지역 해수면 온도 분포가 어떻게 변화할것인지는 지구온난화 연구에서 매우 중요분석하다. 특히, 현재 학자들 사이에서 미래 적도지역 해수면 온도가 엘니뇨 형태와 유사하 게 증가할 것인지 아니면, 서태평양 온도가 크게 증가하는 라니뇨 형태로 증가할 것인지에 대 해 의견이 갈리고 있다. 본 연구에서는 산업혁명 이후 현재까지 해수면 온도 자료분석을 통하 여 현재까지 지구온난화 경향에서 어떤 경향성이 우세한지와 IPCC AR4자료 분석을 통해 미래기 후에서의 경향성까지 분석하여 보았다. 또한, 이러한 현상의 이면에 어떠한 역학과정이 포함되 어 있는지에 대해 초점을 맞추었다.뇨 형태로 증가할 것인지에 대 해 의견이 갈리고 있다. 본 연구에서는 산업혁명 이후 현재까지 해수면 온도 자료분석을 통하 여 현재까지 지구온난화 경향에서 어떤 경향성이 우세한지와 IPCC AR4자료 분석을 통해 미래기 후에서의 경향성까지 분석하여 보았다. 또한, 이러한 현상의 이면에 어떠한 역학과정이 포함되 어 있는지에 대해 초점을 맞추었다. Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5662 2011-01-01T00:00:00Z