Estuary Tides Using Satellite Altimetry And SAR/InSAR Data

Abstract:

It is well known that river and estuary tides are large enough in many regions of the world. If not probably accounted for, tides hinder hydrologic studies and adversely impact other applications such as storm surge predictions in coastal deltaic regions. In regions deprived of gage data, tides have been detected in estuaries, large rivers, or topographic trapped water bodies using satellite geodetic measurements. However, comprehensive modeling of river or estuary tides with high-spatial resolution (~30 m) remains elusive. Here we use three space geodetic techniques, satellite radar altimetry, GPS, and synthetic aperture radar (SAR)/SAR Interferometry data, independently or jointly, in selected regions of coastal wetlands, and rivers to conduct proof of concept studies involving empirical ocean tide modeling. In particular an innovative technique, which infers high-resolution (~30 m) water level observations using polarimetric SAR backscatter data in vegetated estuary, has been developed for empirical tide modeling. In addition to its high spatial resolution, the use of backscatter data would make it easier to construct longer and continuous time series towards resolving tidal frequencies. Despite of the fact that all SAR satellites are on sun synchronous orbits and their data lack the solar tides, we show that some major tidal constituents are indeed retrievable. Here illustrative studies and preliminary tidal modeling results in the Sundarbans mangrove forest estuary, Bangladesh, and the Amazon basin wetlands are presented.