西太平洋洋流系统对海平面高度变化的响应:基于区域海洋模式(ROMS)试验  

The response of the Western Pacific to high-and low-sea levels:based on ROMS experiments

作　　者：李振 覃国金 朱广坤 李兴锐 张彧瑞 LI Zhen;QIN Guojin;ZHU Guangkun;LI Xingrui;ZHANG Yurui(College of Ocean and Earth Science,State Key Laboratory of Marine Environmental Science,Xiamen University,Xiamen 361102,China)

机构地区：[1]厦门大学海洋与地球学院,近海海洋环境科学国家重点实验室,厦门361102

出　　处：《海洋地质与第四纪地质》2025年第2期12-21,共10页Marine Geology & Quaternary Geology

基　　金：国家重点研发计划项目“新近纪晚期印太暖池区海道闭合与高纬冰盖演变的耦合机制研究”(2023YFF0803900);厦门市科技局自然科学基金项目(3502Z20227021)。

摘　　要：地质历史时期海平面变化叠加在板块运动之上,引起海岸线进退、沿海和陆架区域出露或淹没,从而影响全球大洋环流格局和区域海洋系统。本研究聚焦西太平洋对极端海平面升降的响应,使用区域海洋模式(ROMS)探讨末次盛冰期(LGM)情景下极端低海平面SLdrop120(海平面下降120 m)和全球大陆冰盖融化情况下极端高海平面SLrise65(海平面上升65 m)对该区域温盐格局和主要洋流的影响。研究结果显示,海平面升降对该区域洋流系统有重要非线性影响,而对温盐格局影响主要体现在边缘海或靠近大陆边缘区域,且可以通过贯通性变化来解释这些差异。与现代海平面相比,极端低海平面导致近岸陆架海出露、台湾海峡关闭等,切断了西边界流入侵南海,导致东海的黑潮输运向外海方向移动,主轴断面流量减少。与前人考虑LGM冰期气候态的研究结果相比,此减少趋势说明LGM时期海平面降低和冰期气候驱动的效应相抵消。而高海平面则引起岸线向陆推移,渤海等近海海域面积增加、台湾海峡拓宽,使得西边界流向西拓展,对黑潮主流结构有分流作用。关于控制太平洋和印度洋交换的印尼贯穿流ITF,其西支路径因水深较浅而对海平面变化响应更明显。在极端低海平面情景下,卡里马塔海峡关闭、ITF的西支被切断,来自西支的淡水阻塞效应因此消失,这导致通过望加锡海峡的流量反而增加了2.31 Sv(1Sv=1×10^(6)m^(3)/s);相反,在高海平面情景下,西侧的卡里马塔海峡和望加锡海峡均变宽,同时托雷斯海峡打开,使得进入印度洋的流量比现在海平面情景增大。这些结果表明,西太平洋黑潮和印尼贯穿流对海岸线变迁的响应呈非线性规律,并强调了地质历史演化过程中海平面变化对区域洋流的重要作用。Superimposed on tectonic movements,sea level changes during geologic history caused coastline advancement and retreat,exposing shallow shelf or submerging coastal regions,and thus influencing regional ocean currents and global ocean circulation.The Regional Ocean Model(ROMS)was used to simulate the response of the West Pacific thermohaline pattern and major ocean currents in the low sea level scenarios,e.g.,the SLdrop120(sea level drop by 120 m)case during the last glacial maximum(LGM),and the high sea level scenarios,e.g.,the SLrise65(sea level rise by 65 m)case during the global ice sheet melting.Results show that sea level rise and fall have more significant non-linear influences on ocean currents than on temperature and salinity schemes.Compared with the modern sea level,the extremely low sea level led to the exposure of the near-shore shelf sea and the closure of the Taiwan Strait,cutting off the invasion of the western boundary current into the South China Sea,causing the Kuroshio transport in the East China Sea to move toward the open sea and reducing the flow rate in the main axis section.Compared with previous research results considering the LGM glacial climate state,this decreasing trend indicates that the effects of sea level drop during the LGM period and glacial climate driving offset each other.The high sea level pushes the shoreline landward,the area of coastal waters such as the Bohai Sea increases,and the Taiwan Strait widens,causing the western boundary current to expand westward,which would diverse the mainstream of the Kuroshio.Regarding the Indonesian Throughflow(ITF),which controls the exchange between the Pacific and Indian Oceans,its western branch path responds more significantly to sea level changes due to its shallower depth.Under the extreme low sea level scenario,the Karimata Strait is closed and the western branch of the ITF is cut off,so the freshwater blocking effect from the western branch disappears,which leads to an increase of 2.31 Sv(1 Sv=1×10^(6)m^(3)/s)in the flow through

关 键 词：区域海洋模式(ROMS) 东海黑潮(KC) 印尼贯穿流(ITF) 大陆冰量变化 极端海平面升降 

分 类 号：P736[天文地球—海洋地质]