The Northwest Atlantic Ocean Front (NAOF) along the eastern coast of North America, plays a crucial role in shaping regional climate, regulating oceanic energy and mass exchanges, and influencing marine ecosystems and fisheries. Despite its importance, the long-term variability of the NAOF from a three-dimensional perspective remains insufficiently explored. In this study, we use observational and model data to reveal that the NAOF exhibits a centennial-scale natural variability, with a quasi-periodicity of roughly 90–110 years, referred to as the Northwest Atlantic Centennial Variability (NACV). The NACV underwent a significant multi-decadal trend turning around early 1960s. We suggest that the variability of the velocity difference between the Gulf Stream and Labrador Current, serves as a key physical mechanism underlying the NACV. Furthermore, we discover the anomalous surface atmospheric cyclone-anticyclone configuration along the east coast of North America associated with the NACV. Our findings offer valuable insights that may improve our understanding of climate change, marine ecosystem dynamics, and fisheries in the Northwest Atlantic.
 

ocean front, Northwest Atlantic, centennial variability, mutidecadal trend turning