Relationship of the wind-wave from HY-2 scatterometer and radar altimeter data

Abstract

The significant wave height can be measured only on the track of satellite observation, while wind field can be obtained on the whole satellite scan-view region. In this paper, the wind speed retrieved from the HY-2 Scatterometer and significant wave height con-observed from the HY-2 radar altimeter are used to analyze the wind-wave relationship over the western north Pacific and China seas on July 2015. The significant wave height, which is measured from altimeter, is defined as the average height of the highest one-third waves in a wave spectrum, which is the mixture of swells and wind-waves. In order to deeply understand the wind-wave relationship, we use the criteria that is the total amount of energy contained in the wave field is less than or equal to the wave energy for a fully developed sea in terms of wind speed U10. Some the wind speed and significant wave height data eliminated the effect of swell are selected to study the wind-wave relationship, a second-degree polynomial wind-wave relationship is presented. It reveals a nonlinear relationship with the standard error is 0.59m, and it has an approximate linear relationship above 10 m s-1. Those make it possible to get the wind-generated wave information from the satellite-based wind fields. This relationship is coincident with the other two wind-wave models from in situ observations and significant wave height of wind-generated wave is also predicted from the HY2-SCAT wind speed based on this wind-wave model. However, it is still required to be validated by more observations for the wind-wave model, and it is possible to better or operationally apply for wave forecasting based on satellite-retrieved wind speed.