Columbia River plume patterns in summer 2004 as revealed by a hindcast coastal ocean circulation model

Model hindcasts of the Columbia River (CR) plume and coastal ocean circulation in summer 2004 are used to describe the subtidal evolution of plume patterns in response to local wind and to examine the plume influence on shelf circulation. It is found that a bi‐directional plume occurs frequently on the Washington/Oregon shelf, during weak upwelling favorable wind events, during weakening of moderate upwelling favorable wind events, and during weak downwelling events. The high frequency of occurrence of the north plume branch indicates that the CR water will have a significant influence on the Washington shelf in summer.