Swell dissipation from 10 years of Envisat advanced synthetic aperture radar in wave mode

Justin E. Stopa (1) , Fabrice Ardhuin (1) , Romain Husson (1) , Haoyu Jiang , Bertrand Chapron (1) , Fabrice Collard

1 LOPS - Laboratoire d'Océanographie Physique et Spatiale

Swells are found in all oceans and strongly influence the wave climate and air-sea processes. The poorly known swell dissipation is the largest source of error in wave forecasts and hindcasts. We use synthetic aperture radar data to identify swell sources and trajectories, allowing a statistically significant estimation of swell dissipation. We mined the entire Envisat mission 2003-2012 to find suitable storms with swells (13 < T < 18 s) that are observed several times along their propagation. This database of swell events provides a comprehensive view of swell extending previous efforts. The analysis reveals that swell dissipation weakly correlates with the wave steepness, wind speed, orbital wave velocity, and the relative direction of wind and waves. Although several negative dissipation rates are found, there are uncertainties in the synthetic aperture radar-derived swell heights and dissipation rates. An acceptable range of the swell dissipation rate is -0.1 to 6 × 10^-7 m^-1 with a median of 1 × 10^-7 m^-1.

Keywords: turbulence; swell dissipation; wave modeling; air-sea interaction; synthetic aperture radar; Envisat

Domains: Sciences of the Universe [physics]

Justin E. Stopa, Fabrice Ardhuin, Romain Husson, Haoyu Jiang, Bertrand Chapron, et al.. Swell dissipation from 10 years of Envisat advanced synthetic aperture radar in wave mode. Geophysical Research Letters, 2016, 43, pp.3423-3430. ⟨10.1002/2015GL067566⟩. ⟨insu-03682716⟩