Climate Dynamics

, Volume 42, Issue 11–12, pp 3077–3086 | Cite as

The relationship between South Atlantic SST and SACZ intensity and positioning

  • Tatiana JorgettiEmail author
  • Pedro Leite da Silva Dias
  • Edmilson Dias de Freitas


This study explores the ocean–atmosphere interaction in the formation and dynamics of the South Atlantic Convergence Zone (SACZ), through the analysis of the heat sources estimated through the outgoing longwave radiation. The results obtained with this study show that the coupled variability between SACZ and the South Atlantic Ocean indicates that in northern positioned SACZ cases (over Southeastern Brazil), westerly anomalies are verified in the low level continental tropical circulation, consistent with the active phase of the South America Monsoon System (SAMS). In these cases, cold anomalies in the subtropical Atlantic Ocean cause an increase in the continent–ocean temperature gradient, favoring an easterly flow in this region, and blocking the SACZ at a northerly position. Easterly anomalies in the tropical continent were verified in the low level circulation in southern positioned cases (over Southern Brazil), consistent with the SAMS break phase. The SST anomaly patterns indicate cold anomalies in the tropics and warm anomalies in the subtropics, which do not favor the development of an easterly flow at low levels over the western tropical Atlantic. In these cases, two situations may occur: the strengthening of the Low Level Jet (LLJ), which prevails in the eastern subtropical South America and convergence with the South Atlantic Subtropical High at its southern position; or the atmospheric unstable conditions caused by ocean warm SST anomalies (in this case the LLJ may be weaker than its climatological intensity).


South Atlantic Convergence Zone Sea-surface-temperature anomalies Atlantic dipole Singular value decomposition 



This study was supported by FAPESP (T. Jorgetti), CNPq (P. L. Silva Dias) and INCT—Mudanças Climáticas—CNPq.


  1. Barreiro M, Chang P, Saravanan R (2002) Variability of the South Atlantic convergence zone simulated by an atmospheric general circulation model. J Clim 15(7):745–763. doi: 10.1175/1520-0442(2002)015<0745:VOTSAC>2.0.CO;2 CrossRefGoogle Scholar
  2. 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(1):105–114. doi: 10.1007/s00382-004-0487-9 CrossRefGoogle Scholar
  3. Barros V, Gonzalez M, Liebmann B, Camilloni I (2000) Influence of the South Atlantic convergence zone and SouthAtlantic Sea surface temperature on interannual summerrainfall variability in Southeastern South America. Theor Appl Climatol 67(3–4):123–133. doi: 10.1007/s007040070002 CrossRefGoogle Scholar
  4. Björnsson H, Venegas SA (1997) A manual for EOF and SVD analyses of climatic data. Center for Climate and Global Change Research, McGill University, MontrealGoogle Scholar
  5. Bretherton CS, Smith C, Wallace JM (1992) An intercomparison of methods for finding coupled patterns in climate data. J Clim 5(6):541–560. doi: 10.1175/1520-0442(1992)005<0541:AIOMFF>2.0.CO;2 CrossRefGoogle Scholar
  6. Carvalho LMV, Jones C, Liebmann B (2002) Extreme precipitation events in Southeastern South America and large-scale convective patterns in South Atlantic convergence zone. J Clim 15(17):2377–2394. doi: 10.1175/1520-0442(2002)015<2377:EPEISS>2.0.CO;2 CrossRefGoogle Scholar
  7. 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(3). doi: 10.1029/2003GL018647
  8. De Almeida RAF, Nobre P, Haarsma RJ, Campos EJD (2007) Negative ocean–atmosphere feedback in the South Atlantic Convergence Zone. Geophys Res Lett 34(18). doi: 10.1029/2007GL030401
  9. Doyle ME, Barros VR (2002) Midsummer low-level circulation and precipitation in subtropical South America and related sea surface temperature anomalies in the South Atlantic. J Clim 15(23):3394–3410. doi: 10.1175/1520-0442(2002)015<3394:MLLCAP>2.0.CO;2 CrossRefGoogle Scholar
  10. Gandu AW, Silva Dias PL (1998) Impact of tropical heat sources on the South American tropospheric upper circulation and subsidence. J Geophys Res Atmos 103(D6):6001–6015. doi: 10.1029/97JD03114 CrossRefGoogle Scholar
  11. Herdies DL, da Silva A, Silva Dias MAF, Ferreira RN (2002) Moisture budget of the bimodal pattern of the summer circulation over South America. J Geophys Res Atmos 107(D20). doi: 10.1029/2001JD000997
  12. Jones C, Carvalho LMV (2002) Active and break phases in the South American Monsoon system. J Clim 15(8):905–914. doi: 10.1175/1520-0442(2002)015<0905:AABPIT>2.0.CO;2 CrossRefGoogle Scholar
  13. Kalnay E, Mo KC, Paegle J (1986) Large-amplitude, short-scale stationary Rossby waves in the Southern-Hemisphere—observations and mechanistic experiments to determine their origin. J Atmos Sci 43(3):252–275. doi: 10.1175/1520-0469(1986)043<0252:LASSSR>2.0.CO;2 CrossRefGoogle Scholar
  14. Kodama Y (1992) Large-scale features of subtropical precipitation zones (the Baiu frontal zone, the SPCZ, and the SACZ). Part I: characteristics of subtropical frontal zones. J Meteorol Soc Jpn 70(4):813–835Google Scholar
  15. Liebmann B, Smith CA (1996) Description of a complete (interpolated) outgoing longwave radiation dataset. Bull Am Meteorol Soc 77(6):1275–1277Google Scholar
  16. Liebmann B, Kiladis GN, Marengo JA, Ambrizzi T, Glick JD (1999) Submonthly convextive variability over South America and South Atlantic Convergence Zone. J Clim 12(7):1877–1891. doi: 10.1175/1520-0442(1999)012<1877:SCVOSA>2.0.CO;2 CrossRefGoogle Scholar
  17. Reynolds RW, Rayner NA, Smith TM, Stokes DC, Wang WQ (2002) An improved in situ and satellite SST analysis for climate. J Clim 15(13):1609–1625. doi: 10.1175/1520-0442(2002)015<1609:AIISAS>2.0.CO;2 CrossRefGoogle Scholar
  18. Robertson AW, Mechoso CR (2000) Interannual and interdecadal variability of the South Atlantic convergence zone. Mon Weather Rev 128(8):2947–2957. doi: 10.1175/1520-0493(2000)128<2947:IAIVOT>2.0.CO;2 CrossRefGoogle Scholar
  19. Robertson AW, Farrara JD, Mechoso CR (2003) Simulations of the atmospheric response to South Atlantic sea surface temperature anomalies. J Clim 16(15):2540–2551. doi: 10.1175/1520-0442(2003)016<2540:SOTART>2.0.CO;2 CrossRefGoogle Scholar
  20. Seluchi M, Bischoff S, Lichtenstein E (1995) Algunas características de los sistemas sinópticos migratorios que afectan la R. Argentina (Some features of the migratory synoptic systems that affect Argentina). Meteorológica 20:57–66Google Scholar
  21. Teixeira FVB, Tanajura CAS, Toledo EM (2002) An Investigation of the SACZ with extended simulations of the atmospheric model RAMS. Braz J Meteorol 17(1):83–91Google Scholar
  22. Venegas SA, Mysak LA, Straub DN (1997) Atmosphere–ocean coupled variability in the South Atlantic. J Clim 10(11):2904–2920. doi: 10.1175/1520-0442(1997)010<2904:AOCVIT>2.0.CO;2 CrossRefGoogle Scholar
  23. Wallace JM, Smith C, Bretherton CS (1992) Singular value decomposition of wintertime sea-surface temperature and 500-mb height anomalies. J Clim 5(6):561–576. doi: 10.1175/1520-0442(1992)005<0561:SVDOWS>2.0.CO;2 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Tatiana Jorgetti
    • 1
    Email author
  • Pedro Leite da Silva Dias
    • 1
    • 2
  • Edmilson Dias de Freitas
    • 1
  1. 1.Department of Atmospheric Sciences, Institute of Astronomy, Geophysics and Atmospheric SciencesUniversity of São PauloSão PauloBrazil
  2. 2.National Laboratory of Scientific ComputationPetrópolisBrazil

Personalised recommendations