Assessing the Implicit Rain Impact on Sea State During Hurricane Sandy (2012)

Abstract

One of the most understudied and less understood phenomenon in air-sea interaction studies is the effect of rain on the sea state and in turn the atmosphere's response to this surface forcing. In order to examine the entire process, a new parameterization scheme for rain-induced sea surface roughness was incorporated in the two-way atmosphere-ocean wave coupled system Chemical Hydrological Atmospheric Ocean wave System (CHAOS). The simulation of the late October 2012 Hurricane Sandy indicates that the complex rain-on-ocean effect primarily modifies sea surface roughness and attenuates both the atmospheric flow and the ocean wave growth. The heterogeneity of roughness variations modulates the asymmetry of the hurricane and affects its central pressure and its track as well. Comparing with in situ and remotely sensed data, the consideration of rain-on-ocean effect reduces the root-mean-square error up to 8% and 11% for wind speed and significant wave height, respectively, and finally improves Sandy's track offshore eastern U.S. coastline.