2011-10-012024-05-16https://scholars.lib.ntu.edu.tw/handle/123456789/668196摘要:本研究主要在於了解大氣濕對流的各種尺度之間以及地形的交互作用。透過高解析雲解析模式(CRM)的模擬結果分析,本研究的主要目標為發展大氣模式的濕對流之統合參數化。此參數化可以讓全球環流模式在隨著解析度增加的時候,連續地收斂到全球雲解析模式。現今在數值模式中表示深對流的時候,主要的模式物理參數化只有兩種不同的方法:第一種的物理參數化適用於深對流是直接模擬的雲解析模式,第二種的物理參數化則是適用於深對流是採用積雲參數化的環流模式。在理想的狀況下,這兩種物理參數化應該要能整合成一種參數化並且能隨著模式的解析度改變時有著相應的改變。而其中的關鍵方法就是要消除一般傳統環流模式積雲參數化的基本假設,也就是積雲所占的面積遠小於模式的網格大小。成功的整合物理參數化可以大大地增加全球環流模式在不同解析度的實用性。此外,本方法對於使用多重網格的模式也有很大的幫助(例如 multiply-nested grids, adaptive mash refinement),可以使其在多重尺度的模擬中不用擔心其積雲對流的物理參數化。 當數值模式的水平解析度隨著電腦計算資源的增加而大量增加的時候,模式對於其下邊界的處理也變得更為困難。因為下邊界的地形會隨著解析度的增加而變得更加陡峭且不規則。大部份的模式採用座標轉換的方法來處理下邊界的問題,這種方法雖然可以免去地形的處理,然而在計算陡峭地形附近的氣壓梯度力時卻容易產生大量的誤差。本研究的另外一個目標是要發展能夠讓模式處理複雜地形的下邊界條件。我們採用的方法是在使用高度座標的雲解析模式 vector vorticity equation model (VVM) 中加入block mountain。此方法的好處是在處理陡峭地形時,模式座標不會扭曲而產生誤差。成功地使用block mountain不但可以解決在高解析度時的複雜 地形的模擬,也打開了研究對流系統與複雜地形的交互作用之新方向。我們將會模擬高解析雲模式在各種理想化環境的表現並分析其結果以發展適用於各種尺度與不同地形的整合物理參數化。 <br> Abstract: The proposed work focuses on understanding the interaction of the multi-scale atmospheric moist convection with their environment and the surface topography. Through analyzing results from the high-resolution cloud-resolving model (CRM) simulations, the specific objectives are to develop a theoretical framework of a unified parameterization so that the physical parameterizations of a general circulation model (GCM) converge to a global CRM as the horizontal resolution is refined. The interaction of the moist convection and the topography at various horizontal scales will also be investigated. The key for this unified parameterization to succeed is to eliminate the assumption that convective clouds occupy only a small fraction of the grid size, which is commonly used in the conventional parameterization of the GCM either explicitly or implicitly. The cloud fraction, as an additional parameter, is shown to be an important bridge to connect the two types of models. As the horizontal resolution increases, the surface topography generally becomes steeper and more irregular. Thus we will investigate the influence of the topography under various horizontal scales with the newly developed block mountain approach that can handle such irregular topography. The methodology for investigation is based on the analyses of the CRM results under various idealized conditions. Work to be performed with the CRM will be organized as the validation of the unified parameterization and the topography effects.雲解析模式全球環流模式多重尺度模擬積雲參數化複雜地形大氣濕對流的多重尺度模擬之探討