On the feasibility of the use of wind SAR to downscale waves on shallow water

Abstract

Abstract. In recent years, wave reanalyses have become popular as a powerful source of information for wave climate research and engineering applications. These wave reanalyses provide continuous time series of offshore wave parameters; nevertheless, in coastal areas or shallow water, waves are poorly described because spatial resolution is not detailed. By means of wave downscaling, it is possible to increase spatial resolution in high temporal coverage simulations, using forcing from wind and offshore wave databases. Meanwhile, the reanalysis wave databases are enough to describe the wave climate at the limit of simulations; wind reanalyses at an adequate spatial resolution to describe the wind structure near the coast are not frequently available. Remote sensing synthetic aperture radar (SAR) has the ability to detect sea surface signatures and estimate wind fields at high resolution (up to 300 m) and high frequency.In this work a wave downscaling is done on the northern Adriatic Sea, using a hybrid methodology and global wave and wind reanalysis as forcing. The wave fields produced were compared to wave fields produced with SAR winds that represent the two dominant wind regimes in the area: the bora (ENE direction) and sirocco (SE direction). Results show a good correlation between the waves forced with reanalysis wind and SAR wind. In addition, a validation of reanalysis is shown. This research demonstrates how Earth observation products, such as SAR wind fields, can be successfully uptaken into oceanographic modeling, producing similar downscaled wave fields when compared to waves forced with reanalysis wind.

Multi-Spectral Ship Detection Using Optical, Hyperspectral, and Microwave SAR Remote Sensing Data in Coastal Regions

“…The satellite observes the sea surface with a coverage of 15 km and has a total of four multi-spectral bands and one panchromatic band. The sensor has a blue band of 450-520 nm, a green band of 520-600 nm, a red band of 630-690 nm, and a near-infrared band of 760-900 nm with a spatial resolution of 4 m. The Kompsat-2 satellite image used in this study was acquired at Gwangyang Bay in the southern coast of the Korean Peninsula (black box in Figure 3a) at 02:02:33 UTC on 15 March 2016. Figure 3b shows an RGB composite image that contains a number of ships in the bay near the coast.…”

Preface: Oceanographic processes on the continental shelf: observations and modeling

“…Oceanographic processes in the shallow continental shelf and coastal regions have a major impact on human life, since a large fraction of human population lives within 100 km of the shoreline (Halpern et al, 2008). At the same time, the processes occurring in these regions are difficult to analyze and disentangle, because of their intrinsic complexity, the variability of temporal and spatial scales, their multidisciplinary nature, and the influence of offshore boundary conditions (Dickey, 2003;Mitchell et al, 2015).…”