1. The inverse distance weighted (IDW) interpolation method is used for non-hurricane periods. The IDW interpolation is based on the assumption that the interpolating surface should be influenced more by nearby points than by distant points. Shepard’s Method is the simplest form of IDW interpolation (Shepard, 1968). The equation used is described as: equation(3) F(x,y)=∑i=1nwifiwhere n is the number of scatter points in the dataset, fi are the prescribed function values at the scatter points (e.g., the dataset values), and Nutlin-3 purchase wi are the weight functions assigned to each scatter point. The weight function used in the method is
described as follows ( Franke and Nielson, 1980): equation(4) wi=R-hiRhi2∑j=1nR-hjRhj2,where
hi=(x-xi)2+(y-yi)2 is the distance High Content Screening from the interpolation point (x, y) to the scatter point (xi, yi), R is the distance from the interpolation point to the most distant scatter point, and n is the total number of scatter points. To correct the parametric wind, the nudging of the observations from the gauge stations in the Bay area including wind speed, direction, and barometric pressure, was used with a modified inverse distance method. Let F (x , y , t ) be a variable computed from the parametric wind model at node (x , y ). The new variable after correction is F^(x,y,t) which can be expressed as: F^(x,y,t)=∑i=1NWi(x,y)αi(x,y,t)F(x,y,t)where αi(x,y,t)=Fobs(xi,yi,t)F(xi,yi,t)Wi(x,y)=(x-xi)2+(y-yi)2-1∑j(x-xj)2+(y-yj)2-1Wi(x,y)=1,x=xi,y=yiWi(x,y)=0,x=xj,y=yj,wherei≠jαi(x, y, t) isothipendyl is the correction factor for observed variables at the ith station. Fobs are the observed variables at the ith station. N is the total number of observation stations. Wi(x, y) is a weighted function corresponding to the ith observation stations. Fig. 4a showed the observed wind and pressure fields at
the northern and southern Bay during Hurricanes Floyd and Isabel. Examples of the modeled versus observed wind fields during Hurricane Isabel were shown in Fig. 4b for comparison. Given the relatively dense network of the weather stations in the Chesapeake Bay area, the wind and pressure fields results were successfully used in Shen et al., 2005, Shen et al., 2006a and Shen et al., 2006b. Chesapeake Bay receives freshwater inflow from eight major rivers and from more than 150 creeks (Krome and Corlett, 1990). Since most of these creeks are ungauged and small, we can only account for freshwater measurements from the major rivers. These are the Susquehanna River (at the head of the Bay), the Patuxent, Potomac, Rappahannock, Mattaponi, Pamunkey, and James Rivers on the Western Shore, and the Choptank River on the Eastern Shore. Freshwater inflow records are provided by USGS (http://www.waterdata.usgs.gov/nwis).