Coronavirus Information for the UC San Diego Community

Our leaders are working closely with federal and state officials to ensure your ongoing safety at the university. Stay up to date with the latest developments. Learn more.

Effects of anticyclonic eddies on the multicore structure of the North Pacific subtropical mode water based on Argo observations

TitleEffects of anticyclonic eddies on the multicore structure of the North Pacific subtropical mode water based on Argo observations
Publication TypeJournal Article
Year of Publication2019
AuthorsLiu C., Xu LX, Xie SP, Li P.L
Date Published2019/10
Type of ArticleArticle; Early Access
ISBN Number2169-9275
Accession NumberWOS:000499546300001
KeywordsClimatology; evolution; Mesoscale eddies; northwestern part; oceanography; oxygen; subduction; variability
Abstract

The North Pacific subtropical mode water (STMW) often displays a "multicore structure" with more than one minimum in the vertical potential vorticity profile. Anticyclonic eddies (AEs) play an important role in STMW formation and transport, but their effect on the multicore structure of the STMW has not been fully studied. Here, we investigated the formation and evolution of STMW multicore structures in AEs using Argo profiles, which followed two AEs in the STMW formation region for approximately 1.5 years from 2013 to 2015. We found that after the two AEs formed east of 150 degrees E, they trapped the local cold and dense STMW and migrated westward. Since sea surface temperatures increased toward the west, warmer and lighter STMWs were formed during the winter ventilation process as the two AEs moved westward. The newly formed STMW rode on the preexisting cold and dense STMW inside the eddy core, forming a multicore structure in the STMW. Given that water mass properties within AEs are much more conservative, the multicore structure of STMW is much more easily formed inside AEs than outside of eddies. There was a larger (smaller) proportion of profiles containing multiple STMW cores inside (outside) the AE cores, indicating that the AEs were "hot spots" for developing the multicore structure of STMW. The occurrence of the multicore structure of STMW in AEs was highest in spring (March-May) but decreased quickly as the season progressed.

DOI10.1029/2019jc015631
Student Publication: 
No
sharknado