Structure and eastward extension of the Changjiang River plume in the East China Sea

Abstract

The hydrographic structure and offshore extension of freshwater plume discharged from the Changjiang (also known as the Yangtze) River in the northern East China Sea were investigated by analyzing conductivity‐temperature‐depth (CTD) data and drifter trajectories collected during the summers of 1997 and 1998. From June to early September, when southerly winds prevail, the plume tends to move northeast in the Chinese coastal area and then separates from the coastal zone to travel eastward over 400 km offshore across the western shelf of the northern East China Sea. During other seasons, when northerly winds prevail, the plume is confined to the Chinese coast. In the summer the plume in the midshelf, confined to a thin surface layer 10 to 15 m thick, extends eastward in the form of patches of low‐salinity water rather than spreading as a tongue‐shaped pattern from the Changjiang mouth. The eastward movement of patches in the western shelf is primarily due to upwelling favorable southerly winds. Upon reaching the vicinity of Cheju‐do, an island in the middle of northern East China Sea, the patches are advected to the Korea/Tsushima Strait by either the Cheju Warm Current or a northward‐flowing mean current of the Kuroshio Branch Current and then finally flow into the East/Japan Sea.

Joint effect of freshwater plume and coastal upwelling on phytoplankton growth off the Changjiang River

“…During summer, the Changjiang Diluted Water (CDW) flows predominantly eastward (Lie et al, 2003). Therefore, the CJ transect (see Fig.…”

Unique Dispersal of the Changjiang-Diluted Water Plume in the East China Sea Revealed from Satellite Monitoring of Colored Dissolved Organic Matter (CDOM)

“…It is a major source of freshwater on the ECS shelf and supplies about 90% of the total discharge of freshwater from rivers around the ECS and the Yellow Sea (Beardsley et al 1985;Zhang 1996). Freshwater from the Changjiang discharged into the ECS usually mixes with warm, saline waters (the Taiwan Warm Current and the Kuroshio and its branch currents, which flow northeastward over the outer shelf) to form a low salinity water mass called the Changjiangdiluted water (CDW) (Beardsley et al 1985;Ichikawa and Beardsley 2002;Lie et al 2003). The CDW generally has a sea-surface salinity (SSS) value less than 31 or 32 on the ECS shelf (Chang and Isobe 2003;Chen et al 2009;Moon et al 2012).…”

Modeling Offshore Freshwater Dispersal from the Changjiang River and Controlling Factors During Summer

“…The motion of freshwater was also observed using satellite-tracked floats (Lie et al 2003). They found that some floats deployed near the river mouth (at 31.5°N) traveled northward in the shallow coastal region and then traveled northeast toward the west coast of Jeju Island in the shelf region (see their Fig.…”

“…The river discharge is the third largest in the world and the river contributes high levels of nutrients and organic matter to the ECS. The discharge forms a plume of Changjiang diluted water (CDW) by mixing with saline ambient water (Lie et al 2003).…”