Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model

• DOI: 10.1007/s10236-012-0562-4
• Publication Date: 2012-08-12T23:34:26Z
• Authors: Tarang Khangaonkar; Brandon Sackmann; Wen Long; Teizeen Mohamedali; Mindy Roberts
• Keywords: Biogeochemical Cycle; Spring bloom

Nutrient pollution from rivers, nonpoint source runoff, and nearly 100 wastewater discharges is a potential threat to the ecological health of Puget Sound with evidence hypoxia in some basins. However, relative contributions loads entering natural anthropogenic sources, effects exchange flow Pacific Ocean are not well understood. Development quantitative model thus presented help improve our understanding annual biogeochemical cycles this system using unstructured grid Finite-Volume Coastal Model framework Integrated Compartment (CE-QUAL-ICM) water quality kinetics. Results based on 2006 data show that phytoplankton growth die-off, succession between two species algae, nutrient dynamics, dissolved oxygen strongly tied seasonal variation temperature, solar radiation, flushing induced by upwelled waters. Concentrations mixed outflow surface layer occupying approximately 5–20 m upper column strong eutrophication spring summer algae blooms, accompanied depleted nutrients but high levels. The bottom reflects concentrations modulated mixing biologically active Strait Juan de Fuca prior over Admiralty Inlet. effect reflux at Inlet sill resulting lower higher levels waters than incoming reproduced. By late winter, reduction algal activity, constituents interest, were renewed appeared reset cooler nutrient, Ocean.