日本地球惑星科学連合2018年大会

講演情報

[EJ] 口頭発表

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-OS14] 陸域と海洋をつなぐ水循環の素過程

2018年5月22日(火) 13:45 〜 15:15 104 (幕張メッセ国際会議場 1F)

コンビーナ:木田 新一郎(九州大学・応用力学研究所)、山崎 大(東京大学生産技術研究所)、三寺 史夫(北海道大学低温科学研究所、共同)、山敷 庸亮(京都大学大学院総合生存学館)、座長:木田 新一郎(九州大学応用力学研究所)、三寺 史夫山敷 庸亮(京都大学大学院総合生存学館)

14:45 〜 15:00

[AOS14-05] An application of a Lagrangian-Eulerian dispersed multiphase flow model to riverine discharge

★Invited Papers

*松村 義正1 (1.東京大学 大気海洋研究所)

キーワード:浮遊堆積物、ラグランジアン粒子追跡、非静力学海洋モデル、ハイパーピクナルプルーム

While the density of seawater is basically determined by its temperature and salinity, the apparent density increases when the water mass contains a suspended sediment. Simiraly, apparent density declines when water mass contains fine scale materials of lower density such as bubbles and ice crystals. Such density anomaly caused by small suspended materials dispersed in seawater sometimes plays important roles in ocean physics, particularly at coastal regions where the influences of riverine discharge are substantial.

To simulate these oceanic dispersed multiphase flow, a new modeling framework using an online Lagrangian particle tracking method is developed. In this model, Lagrangian particles are dynamically coupled with a finite-volume non-hydrostatic ocean model. The buoyancy force acting on each individual particle is reflected on the RHS of prognostic equation for vertical velocity of continuous water phase at each time-step.

With using this model, idealized and realistic simulations for the transport and sedimentation processes of suspended materials provided by riverine and glacial meltwater discharges have been performed. In the presentation, we specifically introduce the results of hyperpycnal plume simulation where the apparent density of turbid discharge exceeds the density of ambient seawater.