Cross‐Equatorial Anti‐Symmetry in the Seasonal Transport of the Western Boundary Current in the Atlantic Ocean
Name
10.1029-2021JC017184.pdf
Size
2.77 MB
Format
Adobe PDF
Checksum (MD5)
5f2576e737fcf569090f9f2f17bb4a67
Author(s)
Zhai, Yujia
Yang, Jiayan
Wan, Xiuquan
Date Issued
April 23, 2021
Journal
Journal of Geophysical Research: Oceans
Publisher
American Geophysical Union (AGU)
Citation
Zhai, Y., Yang, J., & Wan, X. (2021). Cross-equatorial anti-symmetry in the seasonal transport of the western boundary current in the Atlantic Ocean. Journal of Geophysical Research: Oceans, 126, e2021JC017184.
Version
Author's final manuscript
Abstract
The western boundary current in the equatorial Atlantic Ocean is a main conduit for water-mass exchanges across the equator and thus a major pathway for the interhemispheric transports in the Atlantic Meridional Overturning Circulation (AMOC) system. In this study we quantify and examine the mean and seasonal variability of the equatorial western boundary current (EWBC) in the upper ocean layer using two data-assimilated products, the Estimating the Circulation and Climate of the Ocean (ECCO4r3) and the Simple Ocean Data Assimilation (SODA3). It is found that the EWBC between 10°S and 10°N exhibits two pronounced features in its seasonal variability: (1) the transport varies anti-symmetrically across the equator, that is, the northward EWBC strengthens to the north of the equator when it weakens to the south of the equator, and vice versa; and (2) the amplitude of seasonal variations is much greater in the northern hemisphere than in the south. We hypothesize that the cross-equatorial anti-symmetry in EWBC transport variability is attributable to the impingement of equatorial Rossby waves at the western boundary and the shape of the western boundary is the main cause for the amplified seasonal variability in the northern hemisphere. A simple 1 and 1/2-layer model is used to test and validate this hypothesis and to elucidate the role of wind forcing and topography plays in the seasonal variability in the EWBC transport.
MIT Department
Woods Hole Oceanographic Institution
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2021jc017184
