| 摘要: | 本計晝將探討海溫的日夜變化（diurnal cycle)對熱帶地區氣候次季節尺度的現象Madden and Julian Oscillation (MJO)的影響。在MJO的活躍期肇始之前，海溫的日夜變化極可能為造成觀測 到的淺積雲日變化的主要forcing，低層大氣因此較濕潤而有利於MJO深對流雲的東移。然而大 部分氣候模式無法模擬出正確MJO的特徵，歸因於海洋上層混合層的粗垂直解析度無法準確模 擬海溫的日夜變化以及不夠頻繁的海氣耦合等因素。將一維海洋混合層模式SIT與ECHAM5、 CAM5與HiRAM耦合，顯著改善大部分模式無法準確模擬的MJO模擬。我們將仔細診斷分析 與比較三個模式的模擬結果，分析伴隨MJO的海氣通量對解析海溫日夜變化的敏感度，探討解 析海溫日夜變化對成功模擬MJO的重要性，並了解海氣交互作用對MJO的影響。同時，此一研 究將著重在海洋大陸(Maritime Continent)的模擬分析，探討地形的影響。
Several atmosphere-ocean coupling studies provide evidence of significant impact of the diurnal cycle in SST on the tropical climates, such as ENSO and the Madden-Julian Oscillation (MJO) (e.g. Ham et al., 2009; Danabasoglu et al., 2005; Seo et al., 2014). In most models the diurnal cycle in SST is not well resolved due to insufficient vertical resolution in the upper ocean mixed-layer and insufficiently frequent ocean-atmosphere coupling. In this proposal we will investigate the diurnal coupling impacts for MJO simulation in a climate model, further, to address the role of the diurnal variation of ocean in climate. We utilize the vertical-fine-spacing SIT coupled to three atmospheric general circulation models, CAM5, HiRAM and ECHAM5, to investigate the relative importance of the improved representation of the diurnal cycle of SST on AGCMS. Primary results of coupling simulation with SIT show remarked MJO larger improvements compare to AGCM simulation along. An in-depth inter-model data analysis can further our understanding of the role of air-sea interaction in the MJO. This work is complementary to the integrated research project’s work (氣候變遷實驗室-II) for providing assessment of model simulations of diurnal variability to intraseasonal phenomenon. In addition, the integration used for this study with TaiESM and HiRAM-SIT can contribute to the High Resolution MIP (HiResMIP) in CMIP6. |
