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한반도 겨울철 기온 계절예측을 위한 기후인자 선정 및 통계 모델 개선

저자
우성호 박사
 
작성일
2017.07.04
조회
238
  • 요약
  • 목차

The predictability of seasonal prediction for surface air temperature (SAT) in present is not competent over the mid-latitude, especially over East Asia including the Korean Peninsula. One of the reasons for low predictability of seasonal prediction is closely associated with the unreliable predictability of the operational dynamic models with 3 ~ 4 weeks lead time over the East Asia region. Moreover it is unfeasible that the performance of the dynamic model will be improved within the short-term. Therefore, more information such as the statistical relationship between the predictant (i.e. SAT in the Korean Peninsula) and other climate factors based on the historical dataset is able to be critical for improving the predictability of the operational seasonal prediction.

 

In this study, the statistical prediction model for the SAT over the Korean Peninsula in individual months of the winter season is developed based on multiple regression analysis. For the stable predictability of the model, we tried to discover the climate predictors that are linked physically and dynamically to the SAT in the Korean Peninsula. The possible mechanisms of the relationship between the winter SAT in the Korean Peninsula and its predictors are also suggested in this report.

 

For predicting the SAT in December, three predictors such as the sea ice concentration (SIC) over the Kara-Laptev sea, the tendency of ENSO-related sea surface temperature (SST) over the eastern Pacific and Eurasian snow cover information are used. The relationship between the predictors and the SAT in December is stable during the training period. The model shows the high correlation

skill between the prediction and observational SAT (correlation coefficient : 0.75). The SAT predicted in cross validated hindcast is also highly correlated with the observational SAT (correlation coefficient : 0.71).

 

The models for the SAT in January and February are also constructed using predictors linked dynamically to the SAT in the Korean Peninsula such as the SIC over the upstream region, the SST variability in the tropical Pacific, the SST variability over the North Atlantic, and circulation in upstream of East Asia. Even though the correlation skills of the models for the SAT in January and February are somewhat less than the model for the SAT in December, the models also show useful skill in the correlation between predicted SAT and observation (correlation coefficients : both 0.66 in January and February).

 

We expect that the prediction information produced using our statistical prediction model will be useful and helpful in the operational seasonal prediction for the SAT in the Korean Peninsula.