深海热液羽流系统对研究海底岩石圈和海洋之间的热量与物质输运及深海生物活动等科学问题具有重要意义。文章对温度层结环境中的二维轴对称热液羽流进行了数值模拟。计算结果表明, 热液羽流上升过程中温度不断降低, 浮力减小, 在层结作用下达到最大上升高度。羽流垂向速度在羽流中心区域呈柱状分布, 随着高度的增加速度值逐渐减少。计算得到的羽流最大上升高度和底部羽流半径与经典的MTT理论结果进行了对比, 两者基本一致。而后随着时间增加, 热液羽流顶部开始横向输运形成蘑菇状。示踪物浓度反映的羽流半径在高度0~50m保持不变, 50m以上区域羽流最大半径随时间越来越大, 在1.39h时不到30m, 发展到100h后羽流半径达到150m。
叶丰
,
包芸
. 层结环境中热液羽流物质输运范围的模拟计算*[J]. 热带海洋学报, 2016
, 35(5)
: 97
-102
.
DOI: 10.11978/2015142
The seafloor hydrothermal system plays an important role in exchanges of both thermal energy and chemical components between the ocean and Earth crust, which has revolutionized our understanding of deep- sea biological processes. The hydrothermal system in the temperature background stratification was simulated by an axisymmetric model. Simulation results showed that because the plume continued to entrain fluid, the temperature decreased, the plume overshot to the maximum plume rise height in the stratified environment eventually. The plume’s vertical velocity decreased as the plume rose in its center area. Our results also suggested that the maximum plume rise height and plume’s radius at the bottom agreed with the MTT theory. Over time, a laterally spreading intrusion developed above 50 m. In 0-50 m, the plume’s radius remained unchanged. At 1.39 hours, the plume’s radius was less than 30 m; at 100.00 hours, it become 150 m.
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