The role of the Southern Hemisphere semiannual oscillation in the development of a precursor to central and eastern Pacific Southern Oscillation warm events
Abstract
The semiannual oscillation (SAO) is a twice-yearly northward movement (in May-June-July (MJJ) and November-December-January (NDJ)) of the circumpolar trough of sea level pressure (SLP) in the Southern Hemisphere with effects throughout the troposphere. During MJJ the second harmonic of SLP, describing the SAO, has low values of SLP north of 50°S in the subtropical South Pacific, while the first harmonic, which is dominant over the Australian sector, increases to its peak. This once-a-year peak in negative SLP gradients (decreasing to the east) between Australia and the ocean to its east extends to the equatorial Pacific. Southern Oscillation warm events since 1950, with an intensification of this seasonal cycle, have had larger-amplitude SST anomalies in the eastern equatorial Pacific in MJJ and during the following mature phase in NDJ. Weak amplification of the seasonal cycle in MJJ tends to be followed by larger-amplitude SST anomalies in the central equatorial Pacific during NDJ.
- Authors:
-
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Monash Univ., Melbourne, VIC (Australia). School of Earth, Atmosphere and Environment
- Publication Date:
- Research Org.:
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
- Sponsoring Org.:
- Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division; National Science Foundation (NSF)
- Contributing Org.:
- National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States)
- OSTI Identifier:
- 1473892
- Grant/Contract Number:
- FC02‐97ER62402
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Geophysical Research Letters
- Additional Journal Information:
- Journal Volume: 44; Journal Issue: 13; Journal ID: ISSN 0094-8276
- Publisher:
- American Geophysical Union
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES; semiannual oscillation; El Nino; seasonal cycle
Citation Formats
Meehl, Gerald A., van Loon, Harry, and Arblaster, Julie M. The role of the Southern Hemisphere semiannual oscillation in the development of a precursor to central and eastern Pacific Southern Oscillation warm events. United States: N. p., 2017.
Web. doi:10.1002/2017GL073832.
Meehl, Gerald A., van Loon, Harry, & Arblaster, Julie M. The role of the Southern Hemisphere semiannual oscillation in the development of a precursor to central and eastern Pacific Southern Oscillation warm events. United States. https://doi.org/10.1002/2017GL073832
Meehl, Gerald A., van Loon, Harry, and Arblaster, Julie M. Tue .
"The role of the Southern Hemisphere semiannual oscillation in the development of a precursor to central and eastern Pacific Southern Oscillation warm events". United States. https://doi.org/10.1002/2017GL073832. https://www.osti.gov/servlets/purl/1473892.
@article{osti_1473892,
title = {The role of the Southern Hemisphere semiannual oscillation in the development of a precursor to central and eastern Pacific Southern Oscillation warm events},
author = {Meehl, Gerald A. and van Loon, Harry and Arblaster, Julie M.},
abstractNote = {The semiannual oscillation (SAO) is a twice-yearly northward movement (in May-June-July (MJJ) and November-December-January (NDJ)) of the circumpolar trough of sea level pressure (SLP) in the Southern Hemisphere with effects throughout the troposphere. During MJJ the second harmonic of SLP, describing the SAO, has low values of SLP north of 50°S in the subtropical South Pacific, while the first harmonic, which is dominant over the Australian sector, increases to its peak. This once-a-year peak in negative SLP gradients (decreasing to the east) between Australia and the ocean to its east extends to the equatorial Pacific. Southern Oscillation warm events since 1950, with an intensification of this seasonal cycle, have had larger-amplitude SST anomalies in the eastern equatorial Pacific in MJJ and during the following mature phase in NDJ. Weak amplification of the seasonal cycle in MJJ tends to be followed by larger-amplitude SST anomalies in the central equatorial Pacific during NDJ.},
doi = {10.1002/2017GL073832},
journal = {Geophysical Research Letters},
number = 13,
volume = 44,
place = {United States},
year = {Tue Jun 20 00:00:00 EDT 2017},
month = {Tue Jun 20 00:00:00 EDT 2017}
}
Web of Science
Works referenced in this record:
Two Types of El Niño Events: Cold Tongue El Niño and Warm Pool El Niño
journal, March 2009
- Kug, Jong-Seong; Jin, Fei-Fei; An, Soon-Il
- Journal of Climate, Vol. 22, Issue 6
The zonal harmonic standing waves in the southern hemisphere
journal, February 1972
- van Loon, Harry; Jenne, Roy L.
- Journal of Geophysical Research, Vol. 77, Issue 6
The Curious Case of the EL Niño That Never Happened: A Perspective from 40 Years of Progress in Climate Research and Forecasting
journal, October 2015
- McPhaden, Michael J.; Timmermann, Axel; Widlansky, Matthew J.
- Bulletin of the American Meteorological Society, Vol. 96, Issue 10
The Southern Oscillation. Part VI: Anomalies of Sea Level Pressure on the Southern Hemisphere and of Pacific Sea Surface Temperature during the Development of a Warm Event
journal, February 1987
- van Loon, H.; Shea, D. J.
- Monthly Weather Review, Vol. 115, Issue 2
Indices of El Niño Evolution
journal, April 2001
- Trenberth, Kevin E.; Stepaniak, David P.
- Journal of Climate, Vol. 14, Issue 8
A New Sea Surface Temperature and Sea Ice Boundary Dataset for the Community Atmosphere Model
journal, October 2008
- Hurrell, James W.; Hack, James J.; Shea, Dennis
- Journal of Climate, Vol. 21, Issue 19
Genesis and Evolution of the 1997-98 El Nino
journal, February 1999
- McPhaden, M. J.
- Science, Vol. 283, Issue 5404
A zonal wave 3 index for the Southern Hemisphere: ZONAL WAVE 3 INDEX
journal, December 2004
- Raphael, M. N.
- Geophysical Research Letters, Vol. 31, Issue 23
Relationships between Extratropical Sea Level Pressure Variations and the Central Pacific and Eastern Pacific Types of ENSO
journal, February 2011
- Yu, Jin-Yi; Kim, Seon Tae
- Journal of Climate, Vol. 24, Issue 3
A Southern Hemisphere booster of super El Niño: Lin et al.: Super El Niño
journal, March 2014
- Hong, Li-Ciao; Jin, Fei-Fei
- Geophysical Research Letters, Vol. 41, Issue 6
A modulation of the mechanism of the semiannual oscillation in the Southern Hemisphere
journal, January 1998
- Meehl, Gerald A.; Hurrell, James W.; Loon, Harry Van
- Tellus A: Dynamic Meteorology and Oceanography, Vol. 50, Issue 4
The Southern Oscillation in the Early 1990s
journal, January 2003
- van Loon, Harry
- Geophysical Research Letters, Vol. 30, Issue 9
A Southern Hemisphere sea level pressure-based precursor for ENSO warm and cold events
journal, March 2015
- Hamlington, B. D.; Milliff, R. F.; van Loon, H.
- Journal of Geophysical Research: Atmospheres, Vol. 120, Issue 6
On the definition of El Niño and associated seasonal average U.S. weather anomalies
journal, January 2005
- Larkin, Narasimhan K.
- Geophysical Research Letters, Vol. 32, Issue 13
The Half-Yearly Oscillations in Middle and High Southern Latitudes and the Coreless Winter
journal, September 1967
- van Loon, Harry
- Journal of the Atmospheric Sciences, Vol. 24, Issue 5
The South Pacific Meridional Mode: A Mechanism for ENSO-like Variability
journal, January 2014
- Zhang, Honghai; Clement, Amy; Di Nezio, Pedro
- Journal of Climate, Vol. 27, Issue 2
El Niño Modoki and its possible teleconnection
journal, January 2007
- Ashok, Karumuri; Behera, Swadhin K.; Rao, Suryachandra A.
- Journal of Geophysical Research, Vol. 112, Issue C11
Interannual variations in the half-yearly cycle of pressure gradients and zonal wind at sea level on the Southern Hemisphere
journal, January 1984
- Loon, Harry; Rogers, Jeffery C.
- Tellus A, Vol. 36A, Issue 1
Differences in Atmospheric Circulation between the Development of Weak and Strong Warm Events in the Southern Oscillation
journal, May 2007
- Stephens, David J.; Meuleners, Michael J.; van Loon, Harry
- Journal of Climate, Vol. 20, Issue 10
The Southern Hemisphere semiannual oscillation and circulation variability during the Mid-Holocene
journal, January 2010
- Ackerley, D.; Renwick, J. A.
- Climate of the Past, Vol. 6, Issue 4
Variations in Tropical Sea Surface Temperature and Surface Wind Fields Associated with the Southern Oscillation/El Niño
journal, May 1982
- Rasmusson, Eugene M.; Carpenter, Thomas H.
- Monthly Weather Review, Vol. 110, Issue 5
The changing impact of El Niño on US winter temperatures: IMPACT OF EL NINO ON US TEMPERATURES
journal, August 2012
- Yu, Jin-Yi; Zou, Yuhao; Kim, Seon Tae
- Geophysical Research Letters, Vol. 39, Issue 15
A Reexamination of the Mechanism of the Semiannual Oscillation in the Southern Hemisphere
journal, September 1991
- Meehl, Gerald A.
- Journal of Climate, Vol. 4, Issue 9
Observed Relationships between Oceanic Kelvin Waves and Atmospheric Forcing
journal, October 2006
- Roundy, Paul E.; Kiladis, George N.
- Journal of Climate, Vol. 19, Issue 20
Understanding ENSO Diversity
journal, June 2015
- Capotondi, Antonietta; Wittenberg, Andrew T.; Newman, Matthew
- Bulletin of the American Meteorological Society, Vol. 96, Issue 6
The Southern Hemisphere semiannual oscillation and circulation variability during the Mid-Holocene
journal, January 2010
- Ackerley, D.; Renwick, J. A.
- Climate of the Past, Vol. 6, Issue 4
Understanding ENSO Diversity
journal, June 2015
- Capotondi, Antonietta; Wittenberg, Andrew T.; Newman, Matthew
- Bulletin of the American Meteorological Society, Vol. 96, Issue 6
The Curious Case of the EL Niño That Never Happened: A Perspective from 40 Years of Progress in Climate Research and Forecasting
journal, October 2015
- McPhaden, Michael J.; Timmermann, Axel; Widlansky, Matthew J.
- Bulletin of the American Meteorological Society, Vol. 96, Issue 10
A modulation of the mechanism of the semiannual oscillation in the Southern Hemisphere
journal, August 1998
- Meehl, Gerald A.; Hurrell, James W.; Van Loon, Harry
- Tellus A, Vol. 50, Issue 4
The South Pacific Meridional Mode: A Mechanism for ENSO-like Variability
journal, January 2014
- Zhang, Honghai; Clement, Amy; Di Nezio, Pedro
- Journal of Climate, Vol. 27, Issue 2
Works referencing / citing this record:
Sustained ocean changes contributed to sudden Antarctic sea ice retreat in late 2016
journal, January 2019
- Meehl, Gerald A.; Arblaster, Julie M.; Chung, Christine T. Y.
- Nature Communications, Vol. 10, Issue 1
The Relationship Between South Pacific Atmospheric Internal Variability and ENSO in the North American Multimodel Ensemble Phase‐II Models
journal, November 2019
- You, Yujia; Furtado, Jason C.
- Geophysical Research Letters, Vol. 46, Issue 21