1. ROMS hydrodynamic model ROMS-RCA model for hypoxia prediction RCA biogeochemical model Model forced by NARR/WRF meteorological forcing, river discharge at USGS gauges, climatology or one-way nesting at open boundary, and nutrient (dissolved and particulate) and sediment loadings at rivers (point sources and distributed).

2. Interannual variability is caused by variable water-column respiration in spring (associated with nutrient loading) and variable vertical DO flux (due to summer winds). ROMS-RCA captures interannual variability of hypoxia in CB

3. FVCOM for CB, DB and MAB Resolution: 200 m in estuaries, 1-10 km on the shelf, and 20 vertical layers. Forcing: NARR/WRF, USGS river flow, HYCOM/Global FVCOM at open boundary (one-way nesting). Applications: impacts of climate variability/change on estuaries; storm surges and coastal inundations.

4. Model salinity validation against NOAA buoys in CB

5. Model salinity validation against boat surveys in DB

6. ROMS-RCA predictions of water-quality parameters Some state variables are better predicted than others. Data assimilations can be used to improve parameter estimates and model predictions.