• Title/Summary/Keyword: lagged ensemble technique

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A Prediction of Northeast Asian Summer Precipitation Using Teleconnection (원격상관을 이용한 북동아시아 여름철 강수량 예측)

  • Lee, Kang-Jin;Kwon, MinHo
    • Atmosphere
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    • v.25 no.1
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    • pp.179-183
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    • 2015
  • Even though state-of-the-art general circulation models is improved step by step, the seasonal predictability of the East Asian summer monsoon still remains poor. In contrast, the seasonal predictability of western North Pacific and Indian monsoon region using dynamic models is relatively high. This study builds canonical correlation analysis model for seasonal prediction using wind fields over western North Pacific and Indian Ocean from the Global Seasonal Forecasting System version 5 (GloSea5), and then assesses the predictability of so-called hybrid model. In addition, we suggest improvement method for forecast skill by introducing the lagged ensemble technique.

A Prediction of Precipitation Over East Asia for June Using Simultaneous and Lagged Teleconnection (원격상관을 이용한 동아시아 6월 강수의 예측)

  • Lee, Kang-Jin;Kwon, MinHo
    • Atmosphere
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    • v.26 no.4
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    • pp.711-716
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    • 2016
  • The dynamical model forecasts using state-of-art general circulation models (GCMs) have some limitations to simulate the real climate system since they do not depend on the past history. One of the alternative methods to correct model errors is to use the canonical correlation analysis (CCA) correction method. CCA forecasts at the present time show better skill than dynamical model forecasts especially over the midlatitudes. Model outputs are adjusted based on the CCA modes between the model forecasts and the observations. This study builds a canonical correlation prediction model for subseasonal (June) precipitation. The predictors are circulation fields over western North Pacific from the Global Seasonal Forecasting System version 5 (GloSea5) and observed snow cover extent over Eurasia continent from Climate Data Record (CDR). The former is based on simultaneous teleconnection between the western North Pacific and the East Asia, and the latter on lagged teleconnection between the Eurasia continent and the East Asia. In addition, we suggest a technique for improving forecast skill by applying the ensemble canonical correlation (ECC) to individual canonical correlation predictions.