PO Seminar: Jilian Xiong
Wednesday, November 09, 12:30 PM to 01:30 PM PST
Physical Oceanography Seminar, Autumn 2022
Wednesday, November 9
Jilian Xiong, UW Oceanography
Biophysical interactions control the progression of harmful algal blooms in the lower Chesapeake Bay
Abstract: Harmful algal blooms (HABs) threaten human health, marine life, and coastal economies. Accurate prediction of HABs is still a challenge. Lagrangian particle tracking (LPT) is a popular tool to track algal blooms, yet most LPT models use passive particles to represent algae without considering their interactions with ambient environmental conditions, including water temperature, salinity, available light, and nutrient concentrations. To advance predictions of HABs, we developed a new LPT-Biological (LPT-Bio) model that integrates with a high-resolution numerical model and satellite data. The model is implemented with algal bloom dynamics (mixotrophic growth, respiration, and mortality) and diel vertical migration (DVM), along the predicted transport trajectories. The improved LPT-Bio model was applied to simulate the 2020 Magalefidinium polykrikoides bloom in the lower Chesapeake Bay and successfully captured the bloom intensity/spatial extent and resolved locally aggregated bloom patchiness. We found that capturing DVM behaviors and including mixotrophic growth are critical for simulating M. polykrikoides bloom. The fully coupled LPT-Bio model initialized/calibrated by satellite data and controlled by ambient environmental conditions appeared to be a promising approach to predicting transport pathways, identifying bloom hotspots, resolving bloom concentration variations at sub-grid scales, and providing a basis for developing a forecast system for HABs in the Bay.
12:30 pm, MSB 123 and zoom.
