Quantifying dust deposition over the Atlantic Ocean

Abstract

Abstract. Quantification of atmospheric dust deposition into the Atlantic Ocean is provided. The estimates rely on the four-dimensional structure of atmospheric dust provided by the ESA-LIVAS climate data record established on the basis of CALIPSO-CALIOP observations. The data record of the atmospheric dust deposition rate is provided for the Atlantic Ocean region, between latitudes 60° S and 40° N, and is characterized by 5° (zonal) × 2° (meridional) spatial resolution and seasonal-mean temporal resolution for the period December 2006–November 2022. The estimates of dust deposition are evaluated on the basis of sediment-trap measurements of deposited lithogenic material. The evaluation intercomparison shows a good agreement between the two datasets, revealing the capacity of the satellite-based product to quantitatively provide the amount of dust deposited into the Atlantic Ocean, characterized by a correlation coefficient of 0.79 and a mean bias of 5.42 mg m−2 d−1. Integration of the satellite-based dust deposition rate dataset into AeroVal allowed assessment comparison of the dust deposition product against dust deposition field estimates provided by the MONARCH, EMEP MSC-W, and EC-Earth3-Iron models. The comparison revealed the capacity of the satellite-based product to follow the seasonal activation of dust source regions and the four-dimensional migration of dust transport pathways. Overall, the annual-mean amount of dust deposition into the Atlantic Ocean is estimated at 274.79 ± 31.64 Tg yr−1, of which 243.98 ± 23.89 Tg yr−1 of dust is deposited into the North Atlantic Ocean and 30.81 ± 10.49 Tg yr−1 of dust is deposited into the South Atlantic Ocean. Moreover, a negative statistically significant trend in atmospheric dust deposition over the Atlantic Ocean is revealed. The satellite-based dust deposition product is considered unique with respect to a wide range of potential applications, including compensating for geographical and temporal gaps of sediment-trap measurements, supporting evaluation assessments of model simulations, unraveling physical processes related to the atmospheric cycle of dust, and providing a deeper understanding of dust biogeochemical impacts on oceanic ecosystems, weather, and eventually climate. The atmospheric dust in terms of optical depth and dust deposition rate climate data records relevant to this paper (Proestakis et al., 2025) are available at https://doi.org/10.5281/zenodo.14608539.