Impact of Surface Waves on Wind Stress under Low to Moderate Wind Conditions
Abstract
The impact of ocean surface waves on wind stress at the air-sea interface under low to moderate windconditions was systematically investigated based on a simple constant flux model and flux measurementsobtained from two coastal towers in the East China Sea and South China Sea. It is first revealed that theswell-induced perturbations can reach a height of nearly 30m above the mean sea surface, and these perturbationsdisturb the overlying airflow under low wind and strong swell conditions. The wind profiles severelydepart from the classical logarithmic profiles, and the deviations increase with the peak wave phase speeds. Atwind speeds of less than 4 m/s, an upward momentumtransfer from the wave to the atmosphere is predicted,which is consistent with previous studies. A comparison between the observations and model indicates thatthe wind stress calculated by the model is largely consistent with the observational wind stress when consideringthe effects of surface waves, which provides a solution for accurately calculating wind stress in oceanand climate models. Furthermore, the surface waves at the air-sea interface invalidate the traditionalMonin-Obukhov similarity theory (MOST), and this invalidity decreases as observational height increases.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- May 2020
- DOI:
- 10.5194/egusphere-egu2020-2293
- Bibcode:
- 2020EGUGA..22.2293C