Abstract
The Southern Oscillation (SO) is examined in three 10 year AMIP-type integrations of a 30-level GCM having prescribed monthly mean observed sea surface temperatures for the period January 1979 to December 1988. Three horizontal spectral resolutions of T21, T42 and T79 are investigated and the results are compared with the low-frequency variability, having periods longer than 8 months, in the observed Darwin and Tahiti sea level pressures (SLP) and in the T106 ECMWF analyses from May 1985 to April 1991. Both the ECMWF analyses and the GCM results give unrealistic SLP variability at Tahiti resulting in low Darwin-Tahiti SLP correlations and low S/N ratios for the Tahiti-Darwin SO index. The ECMWF analyses are in particularly poor agreement with the observations during 1987 with anomalously high SLP at Tahiti. Examination of the ECMWF assimilated SSTs, reveals that this may be related to the assimilated SSTs being too cold in the central and eastern equatorial Pacific during mid-1987. The GCM results show the familiar SLP dipole in the tropical Pacific albeit displaced eastwards compared to previous observational studies especially at T42 resolution, thus accounting for the problems at Tahiti which lies near strong gradients in the correlation pattern. Time-longitude diagrams of low-level convergence and correlation maps of upper-level streamfunction suggest that the model is reproducing the SO divergence anomalies although too weakly at T21 resolution and at different longitudinal locations at T42 and T79 resolutions. The time-mean low-level convergences in the GCM simulations give ITCZs and SPCZs in qualitative agreement with the observations with a tendency for increased convergence in the eastern Pacific ITCZ at higher resolution. Longitudinal shifts are not apparent in the time-mean convergence when comparing the GCM results at different resolutions.
Similar content being viewed by others
References
Arkin PA (1983) An examination of the Southern Oscillation in the upper tropospheric tropical and subtropical wind-field. PhD Thesis. University of Maryland, College Park, USA
Boer GJ, Arpe K, Blackburn M, Déquée M, Gates WL, Hart TL, Le Treut H, Roeckner E, Sheinin DA, Simmonds I, Smith RNB, Tokioka T, Wetherald RT, Williamson D (1991) An intercomparison of the climates simulated by 14 atmospheric GCMs. WCRP Rep 58, WMO/TD-425, World Meteorol Organisation, Geneva
Bougeault P (1985) A simple parameterization of the large-scale effects of deep cumulus convection. Mon Weather Rev 113:2108–2121
Cariolle D, Amodei MA, Simon P (1992) Dynamics and the ozone distribution in the winter stratosphere: modelling the inter-hemispheric differences. J Atmos Terr Phys 54:627–640
Cariolle D, Amodei M, Déqué M, Mahfouf J-F, Simon P, Teyssèdre H (1993) A quasi-biennial oscillation signal in general circulation model simulations. Science 261:1313–1316
Chen WY (1982) Assessment of Southern Oscillation sea-level pressure indices. Mon Weather Rev 110:800–807
Déqué M, Dreveton C, Braun A, Cariolle D (1994) The climate version of ARPEGE/IFS: A contribution to the French community climate modelling. Clim Dyn (in press)
Gates WL (1992) AMIP: the atmospheric model intercomparison project. Bull Am Meteorol Soc 73:1962–1970
Geleyn J-F (1987) Use of a modified Richardson number for parameterizing the effect of shallow convection. J Meteorol Soc Japan, NWP symposium: 141–149
Geleyn J-F, Hollingsworth A (1979) An economical analytic method for the computation of the interaction between scattering and line absorption of radiation. Beitr Phys Atmos 52:1–16
Gibson JK, Kallberg P, Nomura A, Uppala S (1993) The ECMWF re-analysis (ERA) project — plans and current status. ECMWF Newsletter 64:3–10, Shinfield Park, Reading, UK
Held IM, Lyons SW, Nigam S (1989) Transients and the extratropical response to El Niño. J Atmos Sci 46:163–174
Hoskins BJ, Hsu HH, James IN, Masutani M, Sardeshmukh PD, White GH (1989) Diagnostics of the global atmospheric circulation based on ECMWF analyses 1979–89. WCRP-27 WMO/TD 326, Geneva
Hurrell JW, Trenberth KE (1992) An evaluation of monthly mean MSU and ECMWF global atmospheric temperatures for monitoring climate. J Clim 5:1424–1440
Karoly DJ (1989) Southern Hemisphere circulation features associated with El Niño-Southern Oscillation events. J Clim 2:1239–1252
Lau N-C (1985) Modeling the seasonal dependence of the atmospheric response to observed El Niños in 1962–76. Mon Weather Rev 113:1970–1996
Lau N-C, Oort AH (1985) Response of a GFDL general circulation model to sea surface temperature fluctuations observed in the tropical Pacific ocean during the period 1962–76. Proc 16th Int Liege Colloq Ocean Hydrodyn. Elsevier Oceanographic Series, pp 289–302
Mahfouf J-F, Cariolle D, Royer J-F, Geleyn J-F, Timbal B (1994) Response of the Météo-France climate model to changes in CO2 and sea surface temperature. Clim Dyn 9:345–362
Meehl GA (1990) Seasonal cycle forcing of El Niño-Southern Oscillation in a global coupled ocean-atmosphere GCM. J Clim 3:72–98
Neelin JD, Latif M, Allart MAF, Cane MA, Cubasch U, Gates WL, Gent PR, Ghil M, Gordon C, Lau NC, Mechoso CR, Meehl GA, Oberhuber JM, Philander SGH, Schopf PS, Sperber KR, Sterl A, Tokioka T, Tribbia J, Zebiak SE (1992) Tropical air-sea interaction in general circulation models. Clin Dyn 7:73–104
Palmer TN (1987) Modelling low frequency variability of the atmosphere. In: Cattle H (ed) Atmosphere and oceanic variability. Royal Meteorological Society London, pp 75–103
Palmer TN, Mansfield DA (1986) A study of the winter time circulation anomalies during past El Niño events using a high resolution general circulation model. QJR Meteorol Soc 112:613–638
Philander SG (1990) El Niño, La Niña and the Southern Oscillation. Academic Press
Philander SG, Lau N-C, Pacanowski RC, Nath MJ (1989) Two different simulations of the Southern Oscillation and El Niño with coupled ocean-atmosphere general circulation models. Phil Trans R Soc London A329:167–178
Rasmusson EM, Wallace JM (1983) Meteorological aspects of the El Niño/Southern Oscillation. Science 222:1195–1202
Reynolds RW (1988) A real-time global sea surface temperature analysis. J Clim 1:75–86
Ropelewski CF, Jones PD (1987) An extension of the Tahiti-Darwin Southern Oscillation index. Mon Weather Rev 115:2161–2165
Sardeshmukh P, Hoskins BJ (1985) Vorticity balances in the tropics during the 1982–83 El Niño-Southern Oscillation event. QJR Meteorol Soc 111:261–278
Shea DJ, Trenberth KE, Reynolds RW (1992) A global monthly sea surface temperature climatology. J Clim 5:987–1001
Shukla J, Wallace JM (1983) Numerical simulation of the atmospheric response to equatorial Pacific sea surface temperature anomalies. J Atmos Sci 40:1613–1630
Spiegel MR (1992) Theory and problems of statistics. Shaum's Outline Series, McGraw-Hill
Sperber KR, Hameed S (1991) Southern oscillation simulation in the OSU coupled upper ocean-atmosphere GCM. Clim Dyn 6:83–97
Trenberth KE (1984) Signal versus noise in the Southern Oscillation. Mon Weather Rev 112:326–332
Trenberth KE (1992) Global analyses from ECMWF. NCAR Techn Note NCAR/TN-373+STR
Trenberth KE, Shea DJ (1987) On the evolution of the Southern Oscillation. Mon Weather Rev 115:3078–3096
Trenberth KE, Olson JG (1988) Evaluation of NMC global analyses. NCAR Techn Note NCAR/TN-299+STR
Trenberth KE, Olson JG, Large WG (1989) A global ocean wind stress climatology based on ECMWF analyses. NCAR Techn Note NCAR/TN-338+STR
Walker GT, Bliss EW (1932) World weather V. Mem R Meteorol Soc 4:53–84
Wright PB (1985) The Southern Oscillation: an ocean-atmosphere feedback system? Bull Am Meteorol Soc 66:398–412
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Stephenson, D.B., Royer, J.F. GCM simulation of the Southern Oscillation from 1979–88. Climate Dynamics 11, 115–128 (1995). https://doi.org/10.1007/BF00211677
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00211677