Surface Suspended Particulate Matter Flux in the Northern Gulf of Mexico From Satellite Observations

The satellite observations of suspended particulate matter (SPM) from the Visible Infrared Imaging Radiometer Suite (VIIRS) and ocean currents from satellite altimetry merged product are used to demonstrate the capability to monitor the SPM flux and characterize and quantify the change of the SPM flux between 2018 and 2023 in the northern Gulf of Mexico (GOM). The sediment was transported out of both the northern GOM and Mississippi River Estuary regions with a peak in the spring season. The zonal alongshore SPM flux dominates the SPM flux, while the meridional SPM flux off the northern GOM is insignificant. In fact, the alongshore SPM flux becomes eastward in summer, while it is westward in the other seasons. Significantly, different SPM fluxes in the northern GOM were found in the 2019 flood year and 2018 drought year. In Mississippi River flood in 2019, the westward zonal SPM flux off Mississippi River Estuary region doubled, and the net SPM flux reached ~100 kg $\cdot~{\mathrm {m}}^{-1}\cdot~{\mathrm {s}}^{-1}$ . On the contrary, the SPM flux in the spring 2018 was significantly weaker than that in the normal year. With combination of gap-free satellite ocean color and satellite altimetry ocean current observations, the SPM flux computation can also be extended to the other world major river estuarine and coastal regions to study the sediment dynamics and further address the ocean physical, biogeochemical, and geological processes in these regions.