Atmospheric Pressure Forcing

The EFDC_Explorer/EFDC+ Modeling System has been updated to include the atmospheric pressure horizontal gradients in the model domain on the hydrodynamics.  This allows EFDC to address pressure variations in large coastal systems.

EFDC+ has been updated for the pressure solution in the CALEXP2T and  CALEXP routines.  The modification does not make any contributions to the hydrodynamic field when  the number of pressure series (NASER) is less than two, because  the horizontal gradient components of atmospheric pressure (pa)  are always zero.  However, if pa is not a constant in the computational domain, then gradients are computed and these will impact the external solution pressure field.  This approach does not violate the hydrostatic assumption

The impact of atmospheric pressure is included in a number of hydrodynamic models including CH3D.  The USACE uses this approach when they are simulating coastal systems. 

Figure 1 shows the Atmospheric Pressure Forcing form in the Hydrodynamics tab of the main EE form.  Here the user can select the Edit button to open each atmospheric series and edit them as shown in Figure 2.  When there are multiple series the Series Weighting button is enabled and the user can set the weighting for the series as shown in Figure 3.  Details of how to set the series weighting are described under Series Weighting. Note that atmospheric series may also be edited in the Temperature | General and Data tab when temperature is being simulated.

Figure 1  Hydrodynamic: Atmospheric Pressure Forcing frame.

Figure 2  Data series for Atmospheric data.

Figure 3  Spatial Weighting Form