Hysteresis of a periodic or leaking western boundary current flowing by a gap  

作　　者：Xinxin Song Dongliang Yuan Zheng Wang 

机构地区：[1]Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences [2]College of Meteorology and Oceanography,National University of Defense Technology [3]Key Laboratory of Marine Science and Numerical Modeling,First Institute of Oceanography,Ministry of Natural Resources [4]University of Chinese Academy of Sciences [5]Function Laboratory for Ocean Dynamics and Climate,Pilot National Laboratory for Marine Science and Technology (Qingdao)

出　　处：《Acta Oceanologica Sinica》2019年第4期90-96,共7页海洋学报（英文版）

基　　金：The National Program on Global Change and Air-Sea Interaction under contract Nos GASI-03-01-01-05,GASIIPOVAI-01-02,GASI-IPOVAI-02,GASI-IPOVAI-03,GASI-IPOVAI-01-05 and GASI-03-01-01-02;the National Natural Science Foundation of China(NSFC)under contract Nos 41421005,41720104008,41476025,41376038 and 41876025;the National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers of China under contract Nos U1606402 and U1606405;the CAS Strategic Priority Project under contract No.XDA11010205;the Scientific and Technological Innovation Project of Qingdao National Laboratory for Marine Science and Technology under contract No.2016ASKJ04;the National Science and Technology Major Project under contract No.2016ZX05057015;the Open Fund of Shandong Provincial Key Laboratory of Marine Ecology and Environment & Disaster Prevention and Mitigation under contract No.201701

摘　　要：A 1.5-layer quasi-geostrophic reduced gravity model is used to study the hysteresis of a periodic or leaking western boundary current(WBC) flowing by a gap. When the periods of the WBC variations are much longer than the Rossby adjustment time scales of the circulation in the vicinity of the gap, the Hopf bifurcations during the Reincrease and Re-decrease loops are delayed to produce a new domain of hysteresis of the Reynolds numbers, and the critical Reynolds numbers of the WBC regime transitions change significantly, with the domain of the hysteresis Reynolds number larger for shorter periodic forcing. When the periods of the WBC variations are comparable to those of the Rossby adjustment time scales of the circulation in the vicinity of the gap, the WBC path inside the gap becomes periodic without hysteresis. The intrusion of the WBC into the western basin generally gets smaller as the period decreases. In addition, the partial leakage of the WBC transport through the gap into the western basin is found to have significant impact on the hysteresis loop of the WBC path when the leaked transport is larger than 1/2 of the WBC. Both the intrusion extent and the critical Reynolds numbers of the WBC regime transition are changed, and the larger the throughflow transport, the larger the change.A 1.5-layer quasi-geostrophic reduced gravity model is used to study the hysteresis of a periodic or leaking western boundary current(WBC) flowing by a gap. When the periods of the WBC variations are much longer than the Rossby adjustment time scales of the circulation in the vicinity of the gap, the Hopf bifurcations during the Reincrease and Re-decrease loops are delayed to produce a new domain of hysteresis of the Reynolds numbers, and the critical Reynolds numbers of the WBC regime transitions change significantly, with the domain of the hysteresis Reynolds number larger for shorter periodic forcing. When the periods of the WBC variations are comparable to those of the Rossby adjustment time scales of the circulation in the vicinity of the gap, the WBC path inside the gap becomes periodic without hysteresis. The intrusion of the WBC into the western basin generally gets smaller as the period decreases. In addition, the partial leakage of the WBC transport through the gap into the western basin is found to have significant impact on the hysteresis loop of the WBC path when the leaked transport is larger than 1/2 of the WBC. Both the intrusion extent and the critical Reynolds numbers of the WBC regime transition are changed, and the larger the throughflow transport, the larger the change.

关 键 词：HYSTERESIS PERIODIC WESTERN BOUNDARY current THROUGHFLOW 

分 类 号：P[天文地球]