Satellites are anticipated to be the critical asset for detecting, identifying, quantifying and tracking PML on large spatial scales. Pioneering works have already identified unique PML spectral reflectance signatures in the UV (350 nm) to SWIR (2500 nm) spectrum. Ongoing research is dedicated to evaluating the need as well as cost of hyperspectral information essential in distinguishing and identifying PML. However, remote sensing of PML can be challenging due to very high water absorption in the NIR-SWIR and masking of the signal during atmospheric correction. Complementary optical information is therefore needed to ensure proper and accurate detection of PML. Measurements of polarization state of water-leaving light have been shown to be a significant tool to disentangle complex marine signal to retrieve water constituents. On another hand, subsurface PML might induce surfactants from “bio-fouling” production. In turn, those surfactants will smooth away capillary waves which can be detectable through polarimetric remote sensing. In the context of the future launch the satellite mission PACE (NASA) and 3MI-Sentinel-5 (ESA, EUMETSAT), embarking hyperspectral radiometers and polarimeters, we propose to fully characterize the polarization signature of PML in relation to other natural seawater constituents through: (i) laboratory experimentation, (ii) in-situ measurements, (iii) existing polarization data from older satellite missions (e.g., PARASOL). For this characterization up-to-date polarimetric sensors will be exploited as well as theoretical modeling of light propagation in PML contaminated waters (accumulation zones in the open ocean and estuarine systems) focusing on the water-leaving polarization and surface surfactants/roughness. This is foreseen as an important complementary effort along those of the Copernicus framework of operational satellite missions Sentinel 1 and 2 which have been shown to have potential monitoring application for PML.
