(11) reproduced the observed salinity, as shown in Fig. 21 by the thick solid line. An additional model test was performed by prescribing precipitation over the entire domain including the continental shelf. The results in this case were not much different from the previous test where the precipitation was only prescribed within the Bay. The model results indicate that the seaward horizontal barotropic pressure gradient induced by precipitation plays a role in retarding the salinity rebound after the salinity rapidly dropped. To improve model accuracy, the spatial distribution

of precipitation input based on observation records is suggested for future model simulation of hurricanes. The response of Chesapeake Bay to forcing from two hurricanes is investigated using an GSI-IX mw unstructured-grid

three-dimensional hydrodynamic model SELFE. The hurricanes chosen for the study are Hurricane Floyd (1999) and Hurricane Isabel (2003), both of which made landfall within 100 km of the mouth of the Bay. The two hurricanes differ in track, strength, translation speed, and precipitation pattern, but the model catches the major features of both events. The model results agree reasonably well with field observations of water level, velocity, and salinity. From the Bay’s water level Protein Tyrosine Kinase inhibitor response to the hurricanes, it was found that the storm surge has two distinct stages: an initial stage set up by the remote winds and the second stage – a primary surge induced by the local winds. For the initial stage, the rising of the coastal oxyclozanide sea level was setup by the remote wind of both hurricanes similarly, but for the second stage, the responses to the two hurricanes’ local winds are significantly different. Hurricane Floyd was followed by down-Bay winds that canceled the initial setup and caused a set-down from the upper Bay. Hurricane Isabel, on the other hand, was followed by up-Bay winds, which reinforced the initial setup and continued to rise up against the

ahead of the upper Bay. The volume flux were estimated at multiple cross-sectional transects throughout the Bay, and it was found consistently from each transect that the net outflow dominated during Hurricane Floyd while the net influx dominated during Hurricane Isabel. The oceanic influxes of water volume and salt flux were setup by the remote winds from the continental shelf into the Bay in the initial stages of the hurricanes. As the hurricanes approached close to the shore, the local wind became more significant. When the hurricanes made landfall, the strong local surface wind stress dominated and was the primary agent in destratifying the water column through transferring turbulent kinetic energy from the surface to the lower layer of the Bay.