Using literature published from 2010 onwards, this study investigates the ~3 500 km extension of the shallow shelf current in the South China Sea(SCS) during the winter and summer monsoons. This current is later ackno...Using literature published from 2010 onwards, this study investigates the ~3 500 km extension of the shallow shelf current in the South China Sea(SCS) during the winter and summer monsoons. This current is later acknowledged as the South China Sea shallow shelf Current(SCSSC). This current is primarily driven by monsoonal winds, and influenced by regional river plumes [Zhujiang(Pearl) River, Hong River, Mekong River] and the prominent South China Sea Warm Current(SCSWC) and South China Sea Western Boundary Current(SCSWBC). The current exhibits significant seasonal variations in both direction and pattern. During winter, it flows along the northern South China Sea's(NSCS) shelf and splits into two branches at the east of Hainan Island. One branch enters the Beibu Gulf through the Qiongzhou Strait and forms a major cyclonic circulation within the gulf, while the other branch flows southwestward along the southern coast of Hainan Island. These branches converge around 16°N latitude at the east of the Vietnamese shelf, then flow southward along the Sunda Shelf, where they deflect southwestward in “broadband”forms before curving southeastward along the east coast of Peninsular Malaysia(ECPM) and exiting via the Karimata Strait. In summer, the current exhibits a complex pattern. At the Sunda Shelf, it flows northwestward along the ECPM,then deflects northeastward around 6°N latitude, forming the Sunda Shelf's anti-cyclonic eddy(SSE) and causing upwelling on the east coast of Peninsular Malaysia(ECPMU). Near the eastern Vietnamese shelf, the current splits around 11°-12°N latitude into three distinct currents: the southward-flowing Vietnam Current, the northward-flowing Vietnam Meandering Current(VMC), and the southward-flowing SCSWBC. The VMC flows northward and then deflects northeastward south of Hainan Island, continuing northeastward along the NSCS's shelf and exiting through the Taiwan Strait.展开更多
太平洋赤道潜流(equatorial undercurrent, EUC)通过影响暖池和冷舌水体交换,对于赤道环流系统的动力过程及其全球气候效应具有重要意义。然而,影响EUC强度变异的风应力结构、触发位置和时期及物理机制并不清晰。基于GECCO (German Cont...太平洋赤道潜流(equatorial undercurrent, EUC)通过影响暖池和冷舌水体交换,对于赤道环流系统的动力过程及其全球气候效应具有重要意义。然而,影响EUC强度变异的风应力结构、触发位置和时期及物理机制并不清晰。基于GECCO (German Contribution to the Estimation of the Circulation and Climate of the Ocean)系统伴随模式,研究了在超前1 a内能够使得140°W断面处EUC流量发生最大变异的风应力扰动结构,及其驱动下EUC变异的物理机制。结果表明:(1)影响EUC变异的敏感风应力主要分布于热带太平洋(15°S~15°N之间),呈现出关于赤道对称的“漏斗”状结构,并随着临近目标月份,呈现自西向东的移动趋势,且EUC流量对纬向风应力的敏感性更强,最大的敏感性强度发生在超前1~3个月内。(2)敏感风应力扰动能够有效引发目标月份EUC流量变异,其中,超前4~11个月的非局地风扰动会导致海盆尺度的EUC增强,超前小于4个月的局地风扰动仅能够导致目标断面附近(±10°)的EUC增强。(3)通过分析海表面高度异常的发展过程,敏感风扰动所激发的赤道Kelvin波、赤道Rossby波及其反射波相互叠加是导致EUC变异的主要原因。上述结果确立了风应力通过赤道波动过程激发中东太平洋局地EUC变异的动力通道。展开更多
基金Long-Term Research Grant Scheme (LRGS:56041)Interaction of Ocean Dynamics With The Climate System of Past,Present,and Future Using Ocean Observation Integrated Data and Numerical Modeling。
文摘Using literature published from 2010 onwards, this study investigates the ~3 500 km extension of the shallow shelf current in the South China Sea(SCS) during the winter and summer monsoons. This current is later acknowledged as the South China Sea shallow shelf Current(SCSSC). This current is primarily driven by monsoonal winds, and influenced by regional river plumes [Zhujiang(Pearl) River, Hong River, Mekong River] and the prominent South China Sea Warm Current(SCSWC) and South China Sea Western Boundary Current(SCSWBC). The current exhibits significant seasonal variations in both direction and pattern. During winter, it flows along the northern South China Sea's(NSCS) shelf and splits into two branches at the east of Hainan Island. One branch enters the Beibu Gulf through the Qiongzhou Strait and forms a major cyclonic circulation within the gulf, while the other branch flows southwestward along the southern coast of Hainan Island. These branches converge around 16°N latitude at the east of the Vietnamese shelf, then flow southward along the Sunda Shelf, where they deflect southwestward in “broadband”forms before curving southeastward along the east coast of Peninsular Malaysia(ECPM) and exiting via the Karimata Strait. In summer, the current exhibits a complex pattern. At the Sunda Shelf, it flows northwestward along the ECPM,then deflects northeastward around 6°N latitude, forming the Sunda Shelf's anti-cyclonic eddy(SSE) and causing upwelling on the east coast of Peninsular Malaysia(ECPMU). Near the eastern Vietnamese shelf, the current splits around 11°-12°N latitude into three distinct currents: the southward-flowing Vietnam Current, the northward-flowing Vietnam Meandering Current(VMC), and the southward-flowing SCSWBC. The VMC flows northward and then deflects northeastward south of Hainan Island, continuing northeastward along the NSCS's shelf and exiting through the Taiwan Strait.
文摘太平洋赤道潜流(equatorial undercurrent, EUC)通过影响暖池和冷舌水体交换,对于赤道环流系统的动力过程及其全球气候效应具有重要意义。然而,影响EUC强度变异的风应力结构、触发位置和时期及物理机制并不清晰。基于GECCO (German Contribution to the Estimation of the Circulation and Climate of the Ocean)系统伴随模式,研究了在超前1 a内能够使得140°W断面处EUC流量发生最大变异的风应力扰动结构,及其驱动下EUC变异的物理机制。结果表明:(1)影响EUC变异的敏感风应力主要分布于热带太平洋(15°S~15°N之间),呈现出关于赤道对称的“漏斗”状结构,并随着临近目标月份,呈现自西向东的移动趋势,且EUC流量对纬向风应力的敏感性更强,最大的敏感性强度发生在超前1~3个月内。(2)敏感风应力扰动能够有效引发目标月份EUC流量变异,其中,超前4~11个月的非局地风扰动会导致海盆尺度的EUC增强,超前小于4个月的局地风扰动仅能够导致目标断面附近(±10°)的EUC增强。(3)通过分析海表面高度异常的发展过程,敏感风扰动所激发的赤道Kelvin波、赤道Rossby波及其反射波相互叠加是导致EUC变异的主要原因。上述结果确立了风应力通过赤道波动过程激发中东太平洋局地EUC变异的动力通道。
