Comparison of HAB tracker results with satellite images (Liu et al., NOAA report)

Harmful Algal Bloom (HAB) Tracking and Toxicity Forecast

Lake Erie HAB tracker model has been used to predict the spatial distribution and temporal movement of harmful algal blooms (HABs) in Lake Erie. It is initialized from satellite-derived cyanobacterial harmful algal bloom (CHAB) concentration, uses the predicted currents from a numerical hydrodynamic model, i.e., the next-generation NOAA Lake Erie Operational Forecast System (LEOFS), and a particle tracking model to produce a 5-day forecast of harmful algal blooms (HABs) in western Lake Erie. The model is useful for public water systems management as well as recreational users of Lake Erie. Besides the further improvement of the HAB tracker model, we have developed a short-term toxicity forecast system to predict the probability of microcystins exceeding specific thresholds.

Dr. Liu virtually presented the toxicity forecast research in IAGLR 2020 Virtual. Click here for the recorded presentation.


M2 ellipses and tidal mixing parameter in Rhode Island coastal waters (Liu et al., 2016,

Coastal and Estuarine Processes

Climate change and human activities are affecting the estuarine and coastal processes by temperature change, acceleration in hydrological cycles, excessive terrigenous nutrient input, etc. We studied coastal and estuarine processes under these stressors, for example, how coastal circulation in Rhode Island coastal waters respond to climate change, how the estuarine exchange between the Great Lakes and a freshwater estuary respond to hydrologic shift, etc.

Flowchart of Carbon, Silicate, Nitrogen Ecosystem Model (CoSiNE; Chai et al., 2001; Liu et al., 2018,

Biophysical Model

Complex modeling systems have provided us with a more complete picture of the related physical and ecological processes. We develop coupled biophysical models to study nutrient cycles and plankton dynamics behind coastal and estuarine processes. For example, how San Francisco Bay ecosystem responds to hydrologic alteration and invasive species, how the Particulate Organic Carbon (POC) and chlorophyll in the coastal East China Sea respond to the construction of the three gorges project.

Coldwater intrusion from Lake Michigan to Muskegon Lake, a freshwater esutary (Liu et al., 2018,


Hydrodynamic Model

We use hydrodynamical models to study coastal hydrodymanics. The hydrodynamic model we've ever used including the Regional Ocean Modeling System (ROMS), the Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM), and the Finite Volume Community Ocean Model (FVCOM).

The oceanic studies involve work in interdisciplinary groups. For example, the study of the anthropogenic stressors’ impact on coastal and estuarine ecosystem is closely related to the upstream land-use choices and practices, wastewater treatment, and weather patterns; Biological scientists and modelers can collaborate to understand the effect of invasive species on the nutrient cycles in coastal systems; The aquatic processes in estuaries are often extensively affected by the groundwater’s input. Therefore, bridging different modeling communities and different disciplines is essential for the understanding of the many factors controlling a healthy coastal ecosystem and habitats, and for the future of coastal environmental protection. I look forward to collaborating with more scientists from different disciplines.