CNR-INSTITUTE OF MARINE SCIENCES-ISMAR (IT)
The particulate backscattering coefficient (bbp) is an indicator of phytoplankton biomass, particulate organic carbon, and particle size distribution in the ocean. This parameter can be estimated through satellite imagery and thus, plays a fundamental role in quantifying net marine primary production and net community production on a global scale. However, to constrain coupled physical and biogeochemical numerical models, accurate satellite-based bbp is needed. Heretofore, most of European Space Agency (ESA) Ocean Science Cluster funded projects are based on global operative bbp products (i.e. ESA OC-CCI), which lack their associated uncertainty compared to in-situ measurements, creating a gap in understanding their impact on related products such as ocean productivity and organic carbon export.
The INSPIRE project aims to address this gap by developing a Global Observing System (GOS) specifically tailored for validating satellite bbp products, harmonising remote sensing, Lagrangian modelling and in-situ data. This involves using a new generation of Surface Velocity Programme (SVP) drifting buoys equipped with backscattering sensors, known as Backscatter-Optical (BO)-SVP drifters. Designed for extended deployment periods, they offer a promising solution for collecting data in challenging marine environments by the combination of the Lagrangian approach and a high frequency sampling. This strategy seeks to pinpoint locations and time frames for drifter launching that maximises the number of in-situ observations usable for match-up activities, as well as showcase a demonstration of the GOS, and validate bbp products using in-situ measurements collected during the project.
To achieve the goals of INSPIRE, three innovative elements will be addressed:
(1) advanced Lagrangian simulations will incorporate an original and effective sub-grid kinematic model, enabling to accurately reconstruct sub- and mesoscale structures, producing reliable predictions of particle dispersion and trajectories in the ocean surface layer, thus addressing from sub-meso to large-scales of ocean dynamics;
(2) simulated Lagrangian trajectories will be constrained with gapped satellite bbp data to evaluate data availability and bbp variability along each trajectory, thus providing optimal sites and time frames for launching BO-SVP drifters to validate bbp products;
(3) validation of satellite bbp products will involve a large dataset of in-situ data collected by globally deployed BO-SVP drifters, with a particular focus on the Mediterranean Sea.
