Circulation

Complex physical processes such as hydrology, nutrient cycling, and sediment transport are linked to water circulation patterns in Puget Sound.

Overview

Complex physical processes such as hydrology, nutrient cycling, and sediment transport are linked to water circulation patterns in Puget Sound. 

Puget Sound. Photo: S.N. Johnson-Roehr (CC BY-NC 2.0) https://www.flickr.com/photos/snjr22/4095840433

Related Articles

The year 2021 was generally drier and warmer including a heat wave in June. Higher river flows followed a rainy and cloudy fall. In 2021, EOPS aerial images continued to capture the diversity of phenomena on the water, with support from its wonderful contributors who documented visible water quality issues across the larger Puget Sound region. With our Artists Corner and story maps on critters in the mud, we hope to continue to inspire, educate, and motivate our community to keep curious and watchful eyes over the environment.

Despite a La Niña, precipitation and rain have been lower since March, leaving only snow-fed rivers running high. Due to lower rainfall and warm summer temperatures the salinity of Puget Sound is now generally higher. Strong blooms and large patches of organic material and macro-algae are building up in many places and wash onto beaches. During very hot summer days, tidal mudflats and beaches can get really warm. Beach wrack can harbor increased bacteria numbers now. See SCUBA cleaning up at Redondo beach.

After a wet winter/spring transition it has been noticeably drier, warmer and sunnier. River flows are near normal levels and in Puget Sound and coastal bays salinity is increasing above normal. The spring bloom is developing but not very pronounced, yet, Noctiluca is already visible in southern Hood Canal. Suspended sediment near rivers and creeks, failing bluffs, and shellfish activities are frequent. Capturing herring spawning from the plane is informative; pilots share their observations.

The Salish Sea Model is a computer model used to predict spatial and temporal patterns related to water circulation in the Salish Sea. It was developed at the United States Department of Energy's Pacific Northwest National Laboratory with funding from the Environmental Protection Agency. It is housed at the University of Washington Center for Urban Waters which is affiliated with the Encyclopedia of Puget Sound.  

We are in a weakening La Niña, coastal downwelling has lessened and we are getting out of a cold and wet stretch, hurray. In March, rivers have almost returned to normal and carry clear water. It’s a good time to go diving if you don’t mind cold water. The productive season has only started in some places and patches of jellyfish are visible. Have a look at this edition and marvel about the secrets of the dead, or mysterious sediment clouds and the oil sheen spotted near Lummi Bay.

A 2021 article in the journal JGR Oceans describes circulation and mixing in the Salish Sea. The findings are based on simulations produced by the LiveOcean computer model.