Hydrodynamics of Western Lake Erie During a Major Harmful Algal Bloom Event

lake erie;FVCOM;harmful algal bloom;School for Environment and Sustainability

Zhou, HuayanJohengen, Thomas ;

University of Michigan

关键词: lake erie;    FVCOM;    harmful algal bloom;    School for Environment and Sustainability;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/148660/Zhou_Huayun_Thesis.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The breakout of a Harmful Algal Bloom (HAB) in Lake Erie in 2014 rendered Toledowithout drinking water for three days. In 2015, Lake Erie subsequently experiencedan even larger algal bloom. These societal and ecosystem impacts of HABs generatedrenewed urgency for HABs research to improve our understanding of the processesdriving HAB development and our ability to better predict and manage them withinthe western basin of Lake Erie.In this study, both observations and model simulations were used for analyzingcirculation patterns responsible for promoting and transporting HABs within thewestern basin. Three surface drifters were released at the edge and inside the bloom inwestern basin Lake Erie in August 2015 that returned time and coordinates for dataanalysis. The observation data from surface drifters were used for validation of thehydrodynamic model Finite Volume Community Ocean Model (FVCOM) output.Next, wind and water levels were analyzed for the period of time when drifters werefloating in the lake. To better understand the drifters’ movements in the lake, aLagrangian particle model, Process TRAJectory (PTRAJ), was forced by currentsfrom FVCOM. The simulated virtual particle paths were then compared with thetrajectories of the surface drifters. Different diffusivities were compared to assess theaccuracy of the PTRAJ model. Finally, lake circulation and meteorological conditionswere compared together for better understanding the physical processes thatcontribute to HABs development and transport. In particular, the wind has asignificant impact on water transport from the nutrient-rich Maumee River estuary iitowards the coastal regions that include the Toledo and Monroe water treatment plantintakes. Summer wind data for 2014, 2015, and 2016 were used to compare withwestern basin circulation. Sustained strong SE-S-SW winds and NE-N-NW-W windswere found most responsible for transporting water, as well as HABs, from MaumeeBay to Monroe and Toledo water intakes respectively.