DOI: 10.1175/JCLI-D-17-0722.1
Scopus记录号: 2-s2.0-85048507673
论文题名: The South Pacific meridional mode as a thermally driven source of ENSO amplitude modulation and uncertainty
作者: Larson S.M. ; Pegion K.V. ; Kirtman B.P.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 13 起始页码: 5127
结束页码: 5145
语种: 英语
英文关键词: Atmosphere-ocean interaction
; ENSO
; Interannual variability
; Pacific decadal oscillation
; South Pacific Ocean
Scopus关键词: Amplitude modulation
; Atmospheric thermodynamics
; Damping
; Heat flux
; Oceanography
; Atmosphere-ocean interactions
; ENSO
; Interannual variability
; Pacific decadal oscillation
; South pacific oceans
; Climatology
; air-sea interaction
; annual variation
; El Nino-Southern Oscillation
; meridional circulation
; Pacific Decadal Oscillation
; prediction
; uncertainty analysis
; wind forcing
; Pacific Ocean
; Pacific Ocean (South)
英文摘要: This study seeks to identify thermally driven sources of ENSO amplitude and uncertainty, as they are relatively unexplored compared to wind-driven sources. Pacific meridional modes are argued to be wind triggers for ENSO events. This study offers an alternative role for the South Pacific meridional mode (SPMM) in ENSO dynamics, not as an ENSO trigger, but as a coincident source of latent heat flux (LHF) forcing of ENSO SSTA that, if correctly (incorrectly) predicted, could reduce (increase) ENSO prediction errors. We utilize a coupled model simulation in which ENSO variability is perfectly periodic and each El Niño experiences identical wind stress forcing. Differences in El Niño amplitude are primarily thermally driven via the SPMM. When El Niño occurs coincidentally with positive phase SPMM, the positive SPMM LHF anomaly counteracts a fraction of the LHF damping of El Niño, allowing for a more intense El Niño. If the SPMM phase is instead negative, the SPMM LHF amplifies the LHF damping of El Niño, reducing the event's amplitude. Therefore, SPMM LHF anomalies may either constructively or destructively interfere with coincident ENSO events, thus modulating the amplitude of ENSO. The ocean also plays a role, as the thermally forced SSTA is then advected westward by the mean zonal velocity, generating a warming or cooling in the ENSO SSTA tendency in addition to the wind-forced component. Results suggest that in addition to wind-driven sources, there exists a thermally driven piece to ENSO amplitude and uncertainty that is generally overlooked. Links between the SPMM and Pacific decadal variability are discussed. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111485
Appears in Collections: 气候减缓与适应
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作者单位: Atmospheric and Oceanic Sciences Department, University of Wisconsin-Madison, Madison, WI, United States; Nelson Institute Center for Climatic Research, University of Wisconsin-Madison, Madison, WI, United States; Department of Atmospheric, Oceanic and Earth Sciences, George Mason University, Fairfax, VA, United States; Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
Recommended Citation:
Larson S.M.,Pegion K.V.,Kirtman B.P.. The South Pacific meridional mode as a thermally driven source of ENSO amplitude modulation and uncertainty[J]. Journal of Climate,2018-01-01,31(13)