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Seasonal Cycle of Background in the Tropical Pacific as a Cause of ENSO Spring Persistence Barrier

Jin, Yishuai ; Liu, Zhengyu ; Lu, Zhengyao LU and He, Chengfei (2019) In Geophysical Research Letters 46(22). p.13371-13378
Abstract

Statistical model results suggest that the declining growth rate from autumn to spring is the key to cause El Niño-Southern Oscillation (ENSO) spring persistence barrier (SPB). Using a dynamical approach, we develop the physical mechanisms responsible for ENSO SPB in the framework of recharge oscillator by adding a seasonally varying Bjerknes (BJ) stability index and linking it with ENSO growth rate. By decomposing BJ index, it is indicated that seasonal thermodynamic damping and thermocline positive feedback play an important role in determining the ENSO SPB. We further show that the increasing/decreasing upper-level cloud/low-level cloud and the deepening thermocline from autumn to spring are the main factors to control the SPB of... (More)

Statistical model results suggest that the declining growth rate from autumn to spring is the key to cause El Niño-Southern Oscillation (ENSO) spring persistence barrier (SPB). Using a dynamical approach, we develop the physical mechanisms responsible for ENSO SPB in the framework of recharge oscillator by adding a seasonally varying Bjerknes (BJ) stability index and linking it with ENSO growth rate. By decomposing BJ index, it is indicated that seasonal thermodynamic damping and thermocline positive feedback play an important role in determining the ENSO SPB. We further show that the increasing/decreasing upper-level cloud/low-level cloud and the deepening thermocline from autumn to spring are the main factors to control the SPB of ENSO. Our proposed mechanisms also have useful implications for the understanding of ENSO prediction.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bjerknes stability index, cloud, El Niño-Southern Oscillation, seasonal persistence barrier, thermocline
in
Geophysical Research Letters
volume
46
issue
22
pages
13371 - 13378
publisher
American Geophysical Union (AGU)
external identifiers
  • scopus:85075516181
ISSN
0094-8276
DOI
10.1029/2019GL085205
language
English
LU publication?
yes
id
0876208f-ba1b-442d-8d9a-c33c3d154265
date added to LUP
2019-12-10 13:28:23
date last changed
2022-04-18 19:22:57
@article{0876208f-ba1b-442d-8d9a-c33c3d154265,
  abstract     = {{<p>Statistical model results suggest that the declining growth rate from autumn to spring is the key to cause El Niño-Southern Oscillation (ENSO) spring persistence barrier (SPB). Using a dynamical approach, we develop the physical mechanisms responsible for ENSO SPB in the framework of recharge oscillator by adding a seasonally varying Bjerknes (BJ) stability index and linking it with ENSO growth rate. By decomposing BJ index, it is indicated that seasonal thermodynamic damping and thermocline positive feedback play an important role in determining the ENSO SPB. We further show that the increasing/decreasing upper-level cloud/low-level cloud and the deepening thermocline from autumn to spring are the main factors to control the SPB of ENSO. Our proposed mechanisms also have useful implications for the understanding of ENSO prediction.</p>}},
  author       = {{Jin, Yishuai and Liu, Zhengyu and Lu, Zhengyao and He, Chengfei}},
  issn         = {{0094-8276}},
  keywords     = {{Bjerknes stability index; cloud; El Niño-Southern Oscillation; seasonal persistence barrier; thermocline}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{22}},
  pages        = {{13371--13378}},
  publisher    = {{American Geophysical Union (AGU)}},
  series       = {{Geophysical Research Letters}},
  title        = {{Seasonal Cycle of Background in the Tropical Pacific as a Cause of ENSO Spring Persistence Barrier}},
  url          = {{http://dx.doi.org/10.1029/2019GL085205}},
  doi          = {{10.1029/2019GL085205}},
  volume       = {{46}},
  year         = {{2019}},
}