Warm Phase of AMV Damps ENSO Through Weakened Thermocline Feedback

Details

• Journal Title:
  Geophysical Research Letters
• Personal Author:
  Trascasa‐Castro, Paloma ; Ruprich‐Robert, Yohan ; Castruccio, Frederic ; Maycock, Amanda C.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research)
• Description:
  Interactions between ocean basins affect El Niño–Southern Oscillation (ENSO), altering its impacts on society. Here, we explore the effect of Atlantic Multidecadal Variability (AMV) on ENSO behavior using idealized experiments performed with the NCAR-CESM1 model. Comparing warm (AMV+) to cold (AMV−) AMV conditions, we find that ENSO sea surface temperature (SST) anomalies are reduced by ∼10% and ENSO precipitation anomalies are shifted to the west during El Niño and east during La Niña. Using the Bjerknes stability index, we attribute the reduction in ENSO variability to a weakened thermocline feedback in boreal autumn. In AMV+, the Walker circulation and trade winds strengthen over the tropical Pacific,
• Keywords:
  General Earth And Planetary Sciences Geophysics General Earth And Planetary Sciences General Earth And Planetary Sciences
• Source:
  Geophysical Research Letters, 48(23)
• DOI:
  https://doi.org/10.1029/2021gl096149
• ISSN:
  0094-8276 ; 1944-8007
• Format:
  PDF
• Publisher:
  American Geophysical Union (AGU)
• Document Type:
  Journal Article
• Funding:
  Grant no. NA13OAR4310138
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:ab3480078e27188c686bc68e34533c227c22b1ddcc202cd1f0a9518240ab43b9
• Download URL:
  https://repository.library.noaa.gov/view/noaa/54898/noaa_54898_DS1.pdf
• File Type:
  [PDF - 2.74 MB ]