Mesoscale energy balance and air-sea interaction in the Kuroshio Extension: low-frequency versus high-frequency variability

View More View Less
  • 1 Physical Oceanography Laboratory/Institute for Advanced Ocean Study, Ocean, University of China and Pilot National Laboratory for Marine Science and Technology, (Qingdao), Qingdao, China
  • 2 Department of Oceanography and Department of Atmospheric Sciences and International Laboratory for High-Resolution Earth System Prediction (iHESP), Texas A&M University, College Station, Texas, USA
  • 3 Department of Oceanography, University of Hawaii at Manoa, Honolulu, Hawaii, USA
© Get Permissions
Restricted access

Abstract

Using eddy-resolving Community Earth System Model (CESM) simulations, this study investigates mesoscale energetics and air-sea interaction at two different time-scale windows in the Kuroshio Extension (KE) region. Based on an energy budget analysis, it is found that both baroclinic and barotropic pathways contribute to eddy energy generation within the low-frequency window (longer than 3 weeks) in this region, while both air-sea heat fluxes and wind stresses act as prominent eddy killers that remove energy from ocean. In contrast, within the high-frequency window oceanic variability is mainly fed by baroclinic instability and regulated by turbulent thermal wind (TTW) processes, while the positive wind work is derived primarily from ageostrophic flow, i.e., Ekman drift, and along with air-sea heat fluxes has little influence on geostrophic mesoscale eddies.

Corresponding author address: Haiyuan Yang, Physical Oceanography Laboratory, Ocean University of China, 238, Songling Road, Qingdao 266100, P.R. China. Email: yanghaiyuan@ouc.edu.cn

Abstract

Using eddy-resolving Community Earth System Model (CESM) simulations, this study investigates mesoscale energetics and air-sea interaction at two different time-scale windows in the Kuroshio Extension (KE) region. Based on an energy budget analysis, it is found that both baroclinic and barotropic pathways contribute to eddy energy generation within the low-frequency window (longer than 3 weeks) in this region, while both air-sea heat fluxes and wind stresses act as prominent eddy killers that remove energy from ocean. In contrast, within the high-frequency window oceanic variability is mainly fed by baroclinic instability and regulated by turbulent thermal wind (TTW) processes, while the positive wind work is derived primarily from ageostrophic flow, i.e., Ekman drift, and along with air-sea heat fluxes has little influence on geostrophic mesoscale eddies.

Corresponding author address: Haiyuan Yang, Physical Oceanography Laboratory, Ocean University of China, 238, Songling Road, Qingdao 266100, P.R. China. Email: yanghaiyuan@ouc.edu.cn
Save