Integrated modeling of air-sea momentum and gas exchange mechanisms and its application to global environmental engineering

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02249
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Kyushu University
• Principal Investigator: Sugihara Yuji 九州大学, 総合理工学研究院, 教授 (70243970)
• Co-Investigator(Kenkyū-buntansha): 山上 路生 京都大学, 工学研究科, 准教授 (80362458) ; 高垣 直尚 兵庫県立大学, 工学研究科, 准教授 (00554221) ; Eljamal Osama 九州大学, 総合理工学研究院, 准教授 (40600052)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 風波 / 運動量交換 / ガス交換 / 砕波 / 地球温暖化

Outline of Final Research Achievements

Through various wind-water tunnel experiments, air-sea momentum and gas exchange mechanisms were investigated from viewpoints of wave motion, breaking wave and turbulence dynamics. Characteristics of the surface transition, surface flow, wave motion, breaking wave, and turbulence at the wind-wave interface were systematically investigated by using a variety of techniques under conditions ranging from low to very high wind speeds, and the dependence of the sea surface drag coefficient on wind speed, wave motion and breaking wave was clarified. In addition, the gas transfer velocity was modeled on the basis of experimental and theoretical findings. By applying the developed model to numerical wave simulation, the influence of wave motion and breaking wave on the sea surface flux estimation in the ocean was investigated.

Free Research Field

地球環境水理学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は，海面境界過程の力学的理解とその応用としての海面フラックス，主に海面抵抗係数とガス交換速度の定式化について重要な知見を与えるものである．特に，様々な条件下で行われた大規模風洞水槽実験のデータは極めて有用であり，地球温暖化や台風の予測に関わる局所大気海洋相互作用の物理的理解に寄与する重要な研究資料となる．これまでの海面抵抗係数やガス交換速度は主として海上風速に基づいてモデル化されてきたが，本研究で示した波浪・砕波の効果を取り入れたモデル化の試みは，新たな予測手法を確立する上で意義のある知見を提示するものである．