日本地球惑星科学連合2018年大会

講演情報

[EE] Eveningポスター発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS11] What we have learned about ocean mixing in the last decade

2018年5月21日(月) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:日比谷 紀之(東京大学大学院理学系研究科地球惑星科学専攻)、Louis St Laurent (Woods Hole Oceanographic Institution)、Ren-Chieh Lien(None、共同)、Robin Ann Robertson (Xiamen University Malaysia)

[AOS11-P13] Diurnal forcing induces variations in seasonal temperature and its rectification mechanism in the eastern shelf seas of China

*郭 新宇1,2Yu Yang2Gao Huiwang2Shi Jie2 (1.愛媛大学沿岸環境科学研究センター、2.中国海洋大学)

キーワード:Diurnal wind forcing、Bottom cold water、Heat flux

This study investigates the seasonal variation in temperature induced by diurnal forcing in the eastern shelf seas of China (ESSC) using a high-resolution Regional Ocean Modeling System model forced by the National Center for Environmental Prediction and the National Center for Atmospheric Research re-analysis data for surface fluxes with both 6-h and daily frequencies, respectively. The comparison between two experiments revealed a ±0.4°C modification of the variation in seasonal temperature by diurnal forcing, which also increases the mixed-layer depth (MLD) in August by 26% and reduces the volume of the Yellow Sea Cold Water Mass (YSCWM) by 25%. Sensitivity experiments using different forcing variables indicated that diurnal wind can explain over 80% of the variability in seasonal temperature induced by diurnal forcing. Diurnal wind led to an increase in the net heat flux into the ocean by about 13 W/m2 in summer and a decrease by about 15 W/m2 in winter. Diurnal wind also generated an additional downward heat transport of 21 W/m2 over the ESSC that contributed to variability in the mean MLD and YSCWM in August. Experiments changing the temporal interval of wind forcing suggested that the increase in the forcing temporal interval gradually enhanced the reproduction of the variability in seasonal temperature generated by diurnal wind; a 6-h wind forcing can capture 70% of this type of variability given by 1-h wind forcing, while a 3-h or shorter wind forcing can capture 90%.