Estimation of Global Wind Energy Input to the Surface Waves Based on the Scatterometer

Mechanical energy input into the ocean from the atmosphere is primarily produced via the ocean surface waves. First, the total wind generation surface wave energy is estimated as nearly 80 TW (1 TM = 10¹² W), based on an empirical formulation and the wave age (β) retrieved from the Earth Remote Sensing-1/2 satellite scatterometer observations. Second, the distribution of the wind-generated surface wave energy density shows that the main input occurs in the westerlies in the Southern Hemisphere and could reach up to 3.58 W/m² with an average value of 0.24 W/m² in the global ocean during a seven-day period. Third, we find that the downward energy flux rate from wind to surface waves can reach around 24% in the Southern Ocean and storm tracks in the northwest Pacific and Atlantic Oceans where the wind waves dominate, but a low downward rate of around 7% in tropical oceans with an average of 11% over the global oceans is observed.