Tropical precipitation regimes and mechanisms of regime transitions: contrasting two aquaplanet general circulation models

Abstract

The atmospheric general circulation models ARPEGE-climate and LMDz are used in an aquaplanet configuration to study the response of a zonally symmetric atmosphere to a range of sea surface temperature (SST) forcing. We impose zonally-symmetric SST distributions that are also symmetric about the equator, with varying off-equatorial SST gradients. In both models, we obtain the characteristic inter-tropical convergence zone (ITCZ) splitting that separates two regimes of equilibrium (in terms of precipitations): one with one ITCZ over the equator for large SST gradients in the tropics, and one with a double ITCZ for small tropical SST gradients. Transition between these regimes is mainly driven by changes in the low-level convergence that are forced by the SST gradients. Model-dependent, dry and moist feedbacks intervene to reinforce or weaken the effect of the SST forcing. In ARPEGE, dry advective processes reinforce the SST forcing, while a competition between sensible heat flux and convective cooling provides a complex feedback on the SST forcing in the LMDz. It is suggested that these feedbacks influence the location of the transition in the parameter range.

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References

  1. Back LE, Bretherthon CS (2008) On the relationship between SST gradients, boundary layer winds and convergence over the tropical oceans. J Clim 22:4182–4196

    Article  Google Scholar 

  2. Barsugli J, Shin SI, Sardeshmukh PD (2005) Tropical climate regimes and global climate sensitivity in a simple setting. J Atmos Sci 62:1226–1240

    Article  Google Scholar 

  3. Belamari S, Pirani A (2007) Validation of the optimal heat and momentum fluxes using the ORCA2-LIM global ocean–ice model. Marine environment and security for the european areaintegrated project (MERSEA IP), deliverable D4.1.3, p 88

  4. Bellon G, Sobel AH (2010) Multiple equilibria of the Hadley circulation in an intermediate–complexity axisymmetric model. J Clim 23:1760–1778

    Article  Google Scholar 

  5. Bjerknes J (1969) Atmospheric teleconnections from the equatorial Pacific. Mon Weather Rev 97:163–172

    Article  Google Scholar 

  6. Bony S, Emanuel JL (2001) A parameterization of the cloudiness associated with cumulus convection; evaluation using TOGA COARE data. J Atmos Sci 58:3158–3183

    Article  Google Scholar 

  7. Bougeault P (1985) A simple parameterisation of the large scale effects of cumulus convection. Mon Weather Rev 4:469–485

    Google Scholar 

  8. Chao WC, Chen B (2004) Single and double ITCZ in an aqua-planet model with constant sea surface temperature and solar angle. Clim Dyn 22:447–459

    Article  Google Scholar 

  9. Charney JG (1971) Tropical cyclogenesis and the formation of the ITCZ. In: Reid WH (ed) Mathematical problems of geophysical fluid dynamics, vol 13, American Mathematical Society, USA, pp 355–368

    Google Scholar 

  10. Cuxart J, Bougeault P, Redelsperger J (2000) A turbulence scheme allowing for mesoscale and large-Eddy simulations. Q J R Meteorol Soc 126:1–30

    Article  Google Scholar 

  11. Dai AG (2006) Precipitation characteristics in 18 coupled climate models. J Clim 19:4605–4630

    Article  Google Scholar 

  12. Déqué M, Dreveton C, Braun A, Cariolle D (1994) The ARPEGE/IFS atmosphere model: a contribution to the French community climate modelling. Clim Dyn 10:249–266

    Article  Google Scholar 

  13. Dijkstra HA, Neelin JD (1995) Ocean–atmosphere interaction and the tropical climatology. Part II: why the Pacific cold tongue is in the east? J Clim 8:1343–1359

    Article  Google Scholar 

  14. Dufresne JL et al. Climate change projections using the IPSL-CM5 earth system model: from CMIP3 to CMIP5. Clim Dyn (submitted)

  15. Emanuel KA (1991) A scheme for representing cumulus convection in large-scale models. J Atmos Sci 48:2313–2335

    Article  Google Scholar 

  16. Fouquart Y, Bonnel B (1980) Computations of solar heating of the earths atmosphere: a new parametrization. Contrib Atmos Phys 53:35–62

    Google Scholar 

  17. Gill AE (1980) Some simple solutions for heat-induced tropical circulation. Q J R Meteorol Soc 106:447–462

    Article  Google Scholar 

  18. Hess PG, Battisti DS, Rasch PJ (1993) Maintenance of the intertropical convergence zones and the tropical circulation on a water-covered earth. J Atmos Sci 50:691–713

    Article  Google Scholar 

  19. Holton JR, Wallace JM, Young JA (1971) On boundary layer dynamics and the ITCZ. J Atmos Sci 28:275–280

    Article  Google Scholar 

  20. Holloway CE, Neelin JD (2007) The convective cold top and quasi equilibrium. J Atmos Sci 64:1467–1487

    Article  Google Scholar 

  21. Hourdin F et al (2006) The LMDZ4 general circulation model: Climate performance and sensitivity to parametrized physics with emphasis on tropical convection. Clim Dyn 27:787–813

    Google Scholar 

  22. Hubert LF, Krueger AF, Winston JS (1969) The double intertropical convergence zone-fact or fiction. J Atmos Sci 26:771–773

    Article  Google Scholar 

  23. Kirtman BP, Schneider EK (2000) A spontaneously generated tropical atmospheric general circulation. J Atmos Sci 57:2080–2093

    Article  Google Scholar 

  24. Lin JL (2007) The double-ITCZ problem in IPCC AR4 coupled GCMs: ocean atmosphere feedback analysis. J Clim 18:4497–4525

    Article  Google Scholar 

  25. Lindzen RS (1974) Wave-CISK in the tropics. J Atmos Sci 31:156–179

    Article  Google Scholar 

  26. Lindzen RS, Nigam S (1987) On the role of the sea surface temperature gradients in forcing the low-level winds and convergence in the tropics. J Atmos Sci 44:2418–2436

    Article  Google Scholar 

  27. Liu Y, Guo L, Wu G, Wang Z (2009) Sensitivity of the ITCZ configuration to cumulus convective parametrizations on an aquaplanet. Clim Dyn 34:223–240

    Article  Google Scholar 

  28. Louis JF (1979) A parametric model of vertical eddy fluxes in the atmosphere. Boundary Layer Meteorol 17:187–202

    Article  Google Scholar 

  29. Mechoso CR and Coauthors (1995) The seasonal cycle over the tropical Pacific in coupled oceanatmosphere general circulation models. Mon Weather Rev 123:2825–2838

  30. Mlawer EJ, Taubman SJ, Brown PD, Iacono MJ, Clough SA (1997) Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave. J Geophys Res 102:16663–16682

    Article  Google Scholar 

  31. Morcrette JJ, Smith L, Fouquart Y (1986) Pressure and temperature dependence of the absorption in longwave radiation parametrizations. Contrib Atmos Phys 59(4):455–469

    Google Scholar 

  32. Neale RB, Hoskins BJ (2000a) A standard test for AGCMs including their physical parameterizations: I: the proposal. Atmos Sci Lett 1:101–107

    Article  Google Scholar 

  33. Neale RB, Hoskins BJ (2000b) A standard test for AGCMs including their physical parameterizations—II: results for the met office model. Atmos Sci Lett 1:108–114

    Article  Google Scholar 

  34. Numaguti A (1993) Dynamics and energy balance of the Hadley circulation and the tropical precipitation zones: significance of the distribution of evaporation. J Atmos Sci 50:1874–1887

    Article  Google Scholar 

  35. Philander SGH, Gu D, Halpern D, Lambert G, Lau NC, Li T, Pacanowski RC (1996) Why the ITCZ is mostly north of the equator? J Clim 9:2958–2972

    Article  Google Scholar 

  36. Ricard JL, Royer JF (1993) A statistical cloud scheme for use in an AGCM. Ann Geophys 11:1095–1115

    Google Scholar 

  37. Schneider EK (2002) Understanding differences between the equatorial Pacific as simulated by two coupled GCMs. J Clim 15:449–469

    Article  Google Scholar 

  38. Voldoire A et al (2011) The CNRM-CM5.1 global climate model: description and basic evaluation. Clim Dyn (in press)

  39. Waliser DE, Somerville RCJ (1994) The preferred latitudes of the intertropical convergence zone. J Atmos Sci 51:1619–1639

    Article  Google Scholar 

  40. Xie SP, Philander SGH (1994) A coupled ocean-atmosphere model of relevance to the ITCZ in the eastern Pacific. Tellus 46A:340–350

    Google Scholar 

  41. Zhang XH, Lin WY, Zhang MH (2007) Toward understanding the double intertropical convergence zone pathology in coupled oceanatmosphere general circulation models. J Geophys Res 112:D12102. doi:10.1029/2006JD007878

    Article  Google Scholar 

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Acknowledgments

The authors would like to thank Aurore Voldoire, Sophie Tytecas and Antoinette Alias for their help on the CNRM-CM5 model. We also would like to thank Florent Brient, Laurent Fairhead and Musat Ionela for their help on the IPSL-CM5A model. Thanks are extended to Sandrine Bony, Laurent Li, Hervé Douville, Jean-Luc Redelsperger for helpful discussions throughout the course of this work. Thanks are also due to the editor and reviewers for their helpful comments.

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Correspondence to Boutheina Oueslati.

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This paper is a contribution to the special issue on the IPSL and CNRM global climate and earth system models, both developed in France and contributing to the 5th coupled model intercomparison project.

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Oueslati, B., Bellon, G. Tropical precipitation regimes and mechanisms of regime transitions: contrasting two aquaplanet general circulation models. Clim Dyn 40, 2345–2358 (2013). https://doi.org/10.1007/s00382-012-1344-x

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Keywords

  • Tropical precipitation regimes
  • Double ITCZ
  • Atmospheric dynamics and feedbacks