A hyperspectral view of the nearshore Mississippi River Delta: characterizing suspended particles in coastal wetlands using imaging spectroscopy

Earth is experiencing unprecedented climate change driven by anthropogenic activities. The Paris Climate Agreement is the most recent international agreement pushing nations to curtail greenhouse gas emissions and balance carbon sources and sinks. To help meet the standards set forth in the Paris Climate Agreement, countries can incorporate ecosystems known to sequester and store carbon into their nationally determined contributions (NDC). Saline, brackish, and freshwater aquatic and wetland ecosystems (i.e., wet carbon) are known for having some of the highest rates of carbon sequestration, and have the capacity to store carbon for long periods of time (e.g., decades to centuries). Integration of wet carbon (WC) systems into NDC is challenging due to their inherent complexities. WC systems are globally expansive, spatially heterogeneous at all scales (e.g., site, local, regional), exhibit temporal variation, and form complex linkages with adjacent terrestrial systems. To study the carbon state of WC systems at the level that is needed for policy, use of remote sensing platforms (e.g., UAV, airborne, and spaceborne) is necessary. Because of the high prevalence of water in WC systems and waters absorption of key electromagnetic wavelengths, multispectral remote sensing is inadequate to fully study WC systems. Imaging spectroscopy has the capability to discern the numerous variables that determine the carbon state of a WC system. To date, imaging spectroscopy has been, generally, underutilized for studying WC systems. The limited availability of imaging spectrometers, compared to multispectral sensors, on all remote sensing platforms has contributed to the lack of more hyperspectral-WC studies. While the past decade has seen increases in hyperspectral-WC studies, we found the global wet carbon habitats are highly unevenly monitored. A new generation of spaceborne imaging spectrometers that will lead the pathway of WC systems mapping and monitoring globally.