本研究使用耦合氣候模式 SPEEDY-NEMO，探討中太平洋（Central Pacific， CP）雲輻射效應（cloud radiative effect， CRE）在聖嬰－反聖嬰（El Niño-La Niña）不對稱性中的角色。觀測與過去研究指出，聖嬰－南方振盪（El Niño-Southern Oscillation， ENSO） 與雲變異之間最強的相關性出現在中太平洋；在北半球冬季的聖嬰事件期間，該區深對流明顯增強，顯示CRE可能對ENSO的演變具有關鍵影響。 本研究進行一組敏感度實驗CP_LWOFF，將 10°S－10°N、160°E－140°W 範圍內的雲長波吸收設為零，並使用 200 年的模式輸出，將其結果與控制實驗（CTL）進行比較。移除中太平洋雲長波吸收後，ENSO的強度與空間結構皆出現顯著變化。聖嬰事件大幅減弱，Niño-3.4 指數振幅明顯降低，同時伴隨 2－7 年年際變率減弱，以及年代際調變幅度降低。相較之下，反聖嬰事件受到的影響較小，使得CTL中原本明顯存在的 聖嬰－反聖嬰振幅不對稱性消失。整體而言，這些結果顯示，中太平洋的雲長波吸收是維持ENSO不對稱性以及支撐強聖嬰事件的重要因素。本研究凸顯CRE在ENSO動力過程中的重要性，並提供了CRE如何調節熱帶氣候變異的新見解。;This study uses the coupled climate model SPEEDY-NEMO to investigate the role of cloud radiative effect (CRE) over the Central Pacific (CP) in shaping El Niño-Southern Oscillation (ENSO) asymmetry. Observations and previous studies indicate that ENSO exhibits its strongest correlation with cloud variability in the CP， where deep convection is markedly enhanced during boreal-winter El Niño events， suggesting a potentially critical influence of CRE on ENSO evolution. A sensitivity experiment， CP_LWOFF， is conducted in which cloud longwave absorption is set to zero within 10°S–10°N and 160°E–140°W， and the results are compared with the control experiment (CTL) using 200 years of model output. After the removal of CP cloud longwave absorption， both the intensity and structure of ENSO undergo significant changes. El Niño events are substantially weakened， with a marked reduction in the Niño-3.4 index amplitude， accompanied by diminished 2–7-year interannual variability and reduced decadal modulation. La Niña events are comparatively less affected， resulting in the disappearance of the pronounced ENSO amplitude asymmetry observed in the CTL. Overall， these results demonstrate that cloud longwave absorption over the Central Pacific is a key factor in maintaining ENSO asymmetry and sustaining strong El Niño events. This study highlights the importance of CRE in ENSO dynamics and provides new insight into the role of CRE in modulating tropical climate variability.
