A Black Hole Eddy Dataset of North Pacific Ocean Based on Satellite Altimetry

Abstract. The methodologies employed for the identification of ocean coherent eddies can be categorized as either Eulerian and Lagrangian. Among Lagrangian structures, Black Hole Eddies (BHEs) exhibit the highest degree of material coherence and conservation, making them particularly suitable for studying the transport and retention of oceanic materials. This study presents an efficient Graphics Processing Unit (GPU) -based BHE identification algorithm, enhancing computational efficiency by approximately 13 times compared to the existing methods. Using this algorithm, the North Pacific Black Hole Eddy dataset (BHE v1.0) is constructed for the first time, based on satellite-derived surface geostrophic velocity data from January 1, 1993 to May 5, 2023 (Tian et al., https://doi.org/10.5281/zenodo.15597447, 2025a). BHE v1.0 contains 18387 eddies with radius larger than 20 km and lifetimes longer than 4 weeks and captures both the spatial-temporal characteristics and the trajectories of coherent eddies throughout lifetimes. Through the advection of Lagrangian particles in Eulerian eddy, rotationally coherent Lagrangian vortices (RCLVs) and BHEs, it is confirmed that BHEs maintain strong material coherence and are able to maintain concentration during their life cycle, preserving their structure without significant filamentation or mixing with surrounding waters. Additionally, approximately 6 % of BHEs, which do not overlap with any RCLVs or Eulerian eddies, are identified and referred to as the Naked Black Hole Eddy and further analyze its coherence through advection. And Transport analysis shows that BHEs induce westward transport about 1.5 Sv, three times weaker than RCLVs, suggesting that they may offer a more accurate estimate of oceanic transport than RCLVs. These finding addresses the existing gap in Black Hole Eddy datasets within the field of oceanography and provides a novel perspective for studying the interactions between coherent eddies and oceanic physical phenomena.