VDatum with spatially varying uncertainty in the northeast Gulf of Mexico from Mobile Bay, Alabama, to Cape San Blas, Florida

A spatially varying uncertainty study on tidal datums was conducted for the Northeast Gulf of Mexico (NEGOF) for VDatum application. The region of interest encompasses Mobile Bay, Alabama, in the west, to Cape San Blas, Florida, in the east. We developed an updated version of the tide model for NEGOF, to incorporate the latest available National Ocean Service (NOS) bathymetry survey data, National Geodetic Survey (NGS) shoreline data, and the updated tidal datum data from the Center for Operational Oceanographic Products and Services (CO-OPS). A gridding technique based on wavelength of long waves in deep ocean was developed to improve ADCIRC model efficiency. Then we applied the spatially varying uncertainty method based on variational approach to the modeled results to produce tidal datum products and associated uncertainty. The spatially varying uncertainty results have been used to help with decision-making on placement of new tide gauges to further reduce the uncertainty in VDatum. The report also documents lessons learned from the model development and testing processes.