The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

Mesoscale eddies accompanied by a highly variable vertical velocity that unable to be directly measured but show great importance in heat and biological material transportation, thus has been a difficulty under-explored. In this study, we analyze the vertical velocities of eddies in a high-resolution (1/32°) idealized domain based on the MITgcm model. A dipole structure of vertical velocity was found in cyclonic eddies, with downwelling occurring in the east and upwelling in the west, while anticyclonic eddies exhibit opposite characteristics. In addition, this opposite dipole pattern also appears in the composite results of eddies with the same polarity in subtropical and frontal regions, respectively. Using quasi-geostrophic omega equation, we have diagnosed and reproduce this dipole pattern and found that the beta-effect has a significant impact on it. Further numerical experiments were conducted to demonstrate the influence of sea level anomalies and background circulation. The study helps deepen the understanding of mesoscale vertical transport, and hopes to inspire further improvement.

eddy,vertical velocity