Abstract
We perform a systematic study of the predictability of surface air temperature and precipitation in Southeastern South America (SESA) using ensembles of AGCM simulations, focusing on the role of the South Atlantic and its interaction with the El Niño-Southern Oscillation (ENSO). It is found that the interannual predictability of climate over SESA is strongly tied to ENSO showing high predictability during the seasons and periods when there is ENSO influence. The most robust ENSO signal during the whole period of study (1949–2006) is during spring when warm events tend to increase the precipitation over Southeastern South America. Moreover, the predictability shows large inter-decadal changes: for the period 1949–1977, the surface temperature shows high predictability during late fall and early winter. On the other hand, for the period 1978–2006, the temperature shows (low) predictability only during winter, while the precipitation shows not only high predictability in spring but also in fall. Furthermore, it is found that the Atlantic does not directly affect the climate over SESA. However, the experiments where air–sea coupling is allowed in the south Atlantic suggest that this ocean can act as a moderator of the ENSO influence. During warm ENSO events the ocean off Brazil and Uruguay tends to warm up through changes in the atmospheric heat fluxes, altering the atmospheric anomalies and the predictability of climate over SESA. The main effect of the air–sea coupling is to strengthen the surface temperature anomalies over SESA; changes in precipitation are more subtle. We further found that the thermodynamic coupling can increase or decrease the predictability. For example, the air–sea coupling significantly increases the skill of the model in simulating the surface air temperature anomalies for most seasons during period 1949–1977, but tends to decrease the skill in late fall during period 1978–2006. This decrease in skill during late fall in 1978–2006 is found to be due to a wrong simulation of the remote ENSO signal that is further intensified by the local air–sea coupling in the south Atlantic. Thus, our results suggest that climate models used for seasonal prediction should simulate correctly not only the remote ENSO signal, but also the local air–sea thermodynamic coupling.
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References
Alexander M, Blade AI, Newman M, Lanzante JR, Lau N-C, Scott JD (2002) The atmospheric bridge: the influence of ENSO teleconnections on air–sea interaction over the global oceans. J Clim 15:2205–2231
Antico PL (2008) Relationships between autumn precipitation anomalies in southeastern South America and El Niño event classification. Int J Climatol. doi:10.1002/joc.1734
Barreiro M, Tippmann A (2008) Atlantic modulation of El Niño influence on summertime rainfall over Southeastern South America. Geophys Res Lett 35:L16704. doi:10.1029/2008GL035019
Barreiro M, Chang P, Saravanan R (2002) Variability of the South Atlantic Convergence Zone as simulated by an atmospheric general circulation model. J Clim 15:745–763
Barreiro M, Chang P, Saravanan R (2005) Simulated precipitation response to SST forcing and potential predictability in the region of the South Atlantic Convergence Zone. Clim Dyn 24:105–114. doi:10.1007/s00382-004-0487-9
Barros VR, Silvestri G (2002) The relationship between sea surface temperature at the subtropical south central Pacific and precipitation in southeastern South America. J Clim 15:251–267
Barros VR, Grimm AM, Doyle ME (2002) Relationship between temperature and circulation in southeastern South America and its influence from El Niño and La Niña events. J Meteo Soc Japan 80:21–32
Barsugli JJ, Battisti DS (1998) The basic effects of atmosphere-ocean thermal coupling on midlatitude variability. J Atmos Sci 55:477–493
Camilloni I, Barros V (2003) Extreme discharge events in the Parana River and their climate forcing. J Hydrol 278:94–106
Chan SC, Behera SK, Yamagata T (2008) Indian Ocean Dipole influence on South American rainfall. Geophys Res Lett 35, L14S12. doi:10.1029/2008GL034204
Chaves RR, Nobre P (2004) Interactions between sea surface temperature over the South Atlantic Ocean and the South Atlantic Convergence Zone. Geophys Res Lett 31:L03204. doi:10.1029/2003GL018647
Chen M, Xie P, Janowiak JE, Arkin PA (2002) Global land precipitation: a 50-yr monthly analysis based on gauge observations. J Hydrometeorol 3:249–266
Chiang JCH, Sobel AH (2002) Tropical tropospheric temperature variations caused by ENSO and their influence on the remote tropical climate. J Clim 15:2616–2631
Diaz AF, Studzinski CD, Mechoso CR (1998) Relationships between precipitation anomalies in Uruguay and southern Brazil and sea surface temperature in the Pacific and Atlantic Oceans. J Clim 11:251–271
Doyle ME, Barros VR (2002) Midsummer low-level circulation and precipitation in subtropical South America related sea surface temperature anomalies in the South Atlantic. J Clim 15:3394–3410
Grimm AM, Barros VR, Doyle ME (2000) Climate variability in Southern South America associated with El Niño and La Niña events. J Clim 13:35–58
Kalnay E, Kanamitsu M, Kistler R, Collins W, Deaven D, Gandin L, Iredell M, Saha S, White G, Woollen J, Zhu Y, Leetmaa A, Reynolds B, Chelliah M, Ebisuzaki W, Higgins W, Janowiak J, Mo KC, Ropelewski C, Wang J, Jenne R, Joseph D (1996) The NCEP/NCAR 40-year reanalysis project. Bull Am Meteorol Soc 77:437–471
Kara AB, Rochford PA, Hurlburt HE (2003) Mixed layer depth variability over the global ocean. J Geophys Res 108(C3). doi:10.1029/2000JC000736
Kiladis GN, Diaz HF (1989) Global climatic anomalies associated with extremes in the Southern Oscillation. J Clim 2:1069–1090
Kucharski F, Molteni F, Bracco A (2005) Decadal interactions between the western tropical Pacific and the North Atlantic Oscillation. Clim Dyn. doi:10.1007/s00382-005-0085-5
Molteni F (2003) Atmospheric simulations using a GCM with simplified physical parametrizations. I. Model climatology and variability in multi-decadal experiments. Clim Dyn 20:175–191
Nobre P, Marengo J, Cavalcanti IAF, Obregon G, Barros V, Camilloni I, Campos N, Ferreira AG (2004) Seasonal-to-decadal predictability and prediction of South American climate. White paper CLIVAR Workshop on Atlantic Predictability, Reading, UK
Nobre P, Marengo JA, Calvacanti IAF, Obregón G, Barros V, Camilloni I, Campos N, Ferreira AG (2006) Seasonal-to-decadal predictability and prediction of South American climate. J Clim 19:5988–6004
Robertson AW, Mechoso CR (2000) Interannual and interdecadal variability of the South Atlantic Convergence Zone. Mon Weather Rev 128:2947–2957
Robertson AW, Farrara JD, Mechoso CR (2003) Simulations of the atmospheric response to South Atlantic sea surface temperature anomalies. J Clim 16:2540–2551
Ropelewski CH, Halpert S (1987) Global and regional scale precipitation patterns associated with the El Niño-Southern Oscillation. Mon Weather Rev 115:1606–1626
Ropelewski CH, Halpert S (1989) Precipitation patterns associated with the high index phase of the Southern Oscillation. J Clim 2:268–284
Saji NH, Ambrizzi T, Ferraz SET (2005) Indian Ocean Dipole mode events and austral surface air temperature anomalies. Dyn Atmos Oceans 39:87–101
Saravanan R, McWilliams JC (1998) Advective ocean-atmosphere interaction: an analytical stochastic model with implications for decadal variability. J Clim 11:168–188
Saravanan R, Chang P (1999) Oceanic mixed layer feedback and tropical Atlantic variability. Geophys Res Lett 26(24):3629–3632
Silvestri GE (2004) El Niño signal variability in the precipitation over southeastern South America during austral summer. Geophys Res Lett 31. doi:10.1029/2004GL020590
Smith TM, Reynolds RW (2004) Improved extended reconstruction of SST (1854–1997). J Clim 17:2466–2477
Taschetto AS, Wainer I (2008) Reproducibility of South American precipitation due to subtropical South Atlantic SSTs. J Clim 21(12):2835–2851
Vianna Cuadra S, Porfirio Da Rocha R (2007) Sensitivity of regional climatic simulation over Southeastern South America to SST specification during austral summer. Int J Climatol 6:793–804
Wang B (1995) Interdecadal changes in El Niño onset in the last four decades. J Clim 8:267–285
Wolter K, Timlin MS (1993) Monitoring ENSO in COADS with a seasonally adjusted principal component index. In: Proceedings of the 17th Climate Diagnostics Workshop, Norman, OK, NOAA/NMC/CAC, NSSL, Oklahoma Climate Survey, CIMMS and the School of Meteorology, University of Oklahoma, pp 52–57
Wolter K, Timlin MS (1998) Measuring the strength of ENSO events—how does 1997/98 rank? Weather 53:315–324
Yulaeva E, Wallace JM (1994) The signature of ENSO in global temperature and precipitation fields derived from the Microwave Sounding Unit. J Clim 7:1719–1736
Acknowledgments
The author would like to thank M. Renom for useful discussions during the course of the study, and to A. Cherchi for commenting on a first version of the manuscript. We also thank two anonymous reviewers for their suggestions that greatly improved the original manuscript. The research leading to these results has received funding from the Programa de Desarrollo Tecnológico in Uruguay, and the European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No 212492.
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Barreiro, M. Influence of ENSO and the South Atlantic Ocean on climate predictability over Southeastern South America. Clim Dyn 35, 1493–1508 (2010). https://doi.org/10.1007/s00382-009-0666-9
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DOI: https://doi.org/10.1007/s00382-009-0666-9