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完全圧縮LESモデルの開発と層積雲の成長過程に関する計算 : 雲・エアロゾル科学への計算科学からの貢献
佐藤, 陽祐;西澤, 誠也;八代, 尚;宮本, 佳明;山浦, 剛;富田, 浩文
Permalink : http://hdl.handle.net/2115/55064
Abstract
本稿では層積雲を対象とした数値実験の結果を用いて, 衛星観測から提唱された二つのダイアグラム（1：雲粒有効半径と光学的厚さの相関パターン；RE-COTパターン, 2：Contoured FrequencyOptical Depth Diagram；CFODD）の時系列を作成し, 先行研究で議論されている雲の成長過程を検証した. 結果からCFODDは雲の鉛直情報を含んでいるためRE-COTパターンより雲の成長過程を効率的に抽出できることが示唆され, 雲の鉛直情報を衛星観測から導出することの重要性を示唆した. これらは数値モデルの結果を基に衛星観測に提言を行うという, 計算科学から雲・エアロゾル科学への貢献の１例である.
This study conducted simulations of stratocumulus using a fully compressible Large Eddy Simulation (LES) model. Using the three-dimensional LES,we investigated the temporal evolution of two types of diagram:(1) the Contoured Frequency Optical Depth Diagram (CFODD), and (2) the correlation pattern between the clouddroplet effective radius and the cloud optical thickness (RE-COT pattern). Our results suggest that part of the cloud lifecycle (i.e., the transition from the non-drizzle to drizzle stage) can be expressed well by the CFODD of individual clouds. However, the cloud lifecycle on the RE-COT pattern was obscure. This advantage of CFODD over the RE-COT pattern arises because the CFODD uses vertical information in the inner cloud, whereas the effective radius of the RE-COT diagram represents properties near the cloud top. Our results emphasize that future satellite observations should retrieve vertical information. This is an example of the contribution of computational science to cloud and aerosol science, and indicates that numerical simulations can be used to augment satellite observations.
This study conducted simulations of stratocumulus using a fully compressible Large Eddy Simulation (LES) model. Using the three-dimensional LES,we investigated the temporal evolution of two types of diagram:(1) the Contoured Frequency Optical Depth Diagram (CFODD), and (2) the correlation pattern between the clouddroplet effective radius and the cloud optical thickness (RE-COT pattern). Our results suggest that part of the cloud lifecycle (i.e., the transition from the non-drizzle to drizzle stage) can be expressed well by the CFODD of individual clouds. However, the cloud lifecycle on the RE-COT pattern was obscure. This advantage of CFODD over the RE-COT pattern arises because the CFODD uses vertical information in the inner cloud, whereas the effective radius of the RE-COT diagram represents properties near the cloud top. Our results emphasize that future satellite observations should retrieve vertical information. This is an example of the contribution of computational science to cloud and aerosol science, and indicates that numerical simulations can be used to augment satellite observations.
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