Antarctic Bottom Water Warming, Freshening, and Contraction in the Eastern Bellingshausen Basin

Details

• Journal Title:
  Geophysical Research Letters
• Personal Author:
  Johnson, Gregory C. ; Mahmud, A. K. M. Sadman ; Macdonald, Alison M. ; Twining, Benjamin S.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; PMEL (Pacific Marine Environmental Laboratory)
• Description:
  Antarctic Bottom Water has been warming in recent decades throughout most of the oceans and freshening in regions close to its Indian and Pacific sector sources. We assess warming rates on isobars in the eastern Pacific sector of the Southern Ocean using CTD data collected from shipboard surveys from the early 1990s through the late 2010s together with CTD data collected from Deep Argo floats deployed in the region in January 2023. We show cooling and freshening in the temperature‐salinity relation for water colder than ∼0.4°C. We further find a recent acceleration in the regional bottom water warming rate vertically averaged for pressures exceeding 3,700 dbar, with the 2017/18 to 2023/24 trend of 7.5 (±0.9) m°C yr−1 nearly triple the 1992/95 to 2023/24 trend of 2.8 (±0.2) m°C yr−1. The 0.2°C isotherm descent rate for these same time periods nearly quadruples from 7.8 to 28 m yr−1.
• Source:
  Geophysical Research Letters, 51(13)
• DOI:
  https://doi.org/10.1029/2024gl109937
• ISSN:
  0094-8276 ; 1944-8007
• Format:
  pdf
• Publisher:
  American Geophysical Union (AGU)
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/licenses/by-nc-nd/4.0/
• Rights Information:
  CC BY-NC-ND
• Compliance:
  Library
• Main Document Checksum:
  urn:sha-512:170c81c813e000dcff4cf76cb71d6e1e4a46e0b7e1b4220a55feaac1152eca69552a2b04011cc569a07f9aa8ad8c852d6ae1b45ff6ecdac5cec3a94e5d5cff92
• Download URL:
  https://repository.library.noaa.gov/view/noaa/68699/noaa_68699_DS1.pdf
• File Type:
  [PDF - 1.06 MB ]