Seasonal migration of the Yellow Sea Bottom Cold Water

Abstract

The three-dimensional motion of the Yellow Sea Bottom Cold Water (YSBCW) and the relevant dynamical factors are studied using a regional circulation model and the two-way Lagrangian particle tracking method (PTM). The simulated results are in good agreement with hydrographic observations. The trajectories of the modeled particles show that the subsurface cold heavy water mass from the northern part of the Yellow Sea gradually sinks into deeper layers along the western slope of the Yellow Sea trough with a southward movement from spring to summer. The cold water mass gradually gathers speed from early March to July or August, and eventually reaches its southernmost location in late September or early October. Furthermore, sensitivity experiments demonstrate that tide-induced residual currents under baroclinic conditions are the dominant factor driving deep circulation during summertime in the Yellow Sea. The summer southerly wind and strong surface solar radiation are the secondary factors influencing the southward migration. This study also proposes an improved delimitation for the YSBCW based on temperature statistics in the central basin (deeper than 40 m) between 35 N and 39 N in March with an increase in rate of approximately 0.7 C/month, which is more appropriate than the constants of the 8 C or 10 C isotherms frequently used.

Novel, Repeated Surveys Reveal New Insights on Sediment Flux Through a Narrow Strait, Bohai, China

“…Below the thermocline, a uniform cold water mass was isolated from ambient warmer waters (Figure d). This cold pool, also known as the Yellow Sea Cold Water Mass revealed by many in situ observations and numerical models (Chen et al, ; Hur et al, ), is one of the most prominent late spring‐summer oceanographic phenomena in this area (Wang, Hirose, et al, ). It forms locally during the previous winter due to surface cooling and strong vertical mixing (Park et al, ; Zhang et al, ).…”

Seasonal evolution of the Yellow Sea Cold Water Mass and its interactions with ambient hydrodynamic system

“…The YSCWM was previously thought to originate locally from previous winter water [ Ho et al ., ]. But more recent studies have shown that there can also be a southward movement of water from the northern Yellow Sea in summer due to tidal‐induced residual currents [ Teague and Jacobs , ; Zhang et al ., ; Moon et al ., ; Park et al ., ; Wang et al ., ]. A complete description of the spatial and temporal evolution of the YSCWM can best be achieved through numerical modeling validated with high‐resolution, long‐duration time series of local current velocity, temperature and salinity.…”

The use of statolith analyses and particle‐tracking experiments to reveal the migratory route of the swordtip squid (Uroteuthis edulis) caught on the Pacific side of Japan

“…edulis are caught via torch‐light fishing (Arkhipkin et al., ) indicates that squid migrate upward mainly for feeding at night and that they are transported by the ocean current. In the present study, squid motions were simulated by particle tracking with the fourth‐order Runge‐Kutta method as described by Wang, Hirose, Kang, and Takayama (). The particle locations were calculated at 2 hr intervals.…”