Bright Oceans: Spectral differentiation of whitecaps, sea ice, plastics, and other flotsam

Viewed from space, the ocean is a dark surface underlying a thick atmosphere which reflects sunlight back to the sensor. More than 90% of the signal measured from an ocean color satellite occurs from molecular scattering within the atmosphere and only a few percent of the signal represents photons that have penetrated into the ocean. Ocean surfaces, however, are not always dark. Various optically active constituents both in the water and on the sea surface can enhance the surface albedo and make the oceans appear much brighter than normal. These bright waters with enhanced water reflectance can result from the presence of whitecaps and foam, sea ice, plastics, and other flotsam at the sea surface. Differentiating between these sea surface constituents, many of which appear white or spectrally flat in the visible spectrum, is the objective of this study with the intent to understand how the unique reflectance features of different floating materials can be used to develop new parameters from ocean color imagery from the PACE mission. Hyperspectral field measurements from the visible to shortwave infrared of different targets will be presented, as well as some applications to airborne PRISM imagery and hyperspectral satellite imagery that serve as analogs to the PACE mission.