Abstract
An ocean general circulation model is used to study the influence of positive precipitation anomalies associated with El Nino and La Nina events. In this idealized model, the precipitation over the appropriate part of the equatorial Indo-Pacific region is doubled for one year. At the surface, salinity anomalies of up to −0.9 parts per thousand result from this anomalous precipitation. Perturbation surface currents ranging from 10–100% of the climatological values are induced in the tropical Indian and Pacific Oceans. A return flow is found beneath the thermocline with upwelling (downwelling) in (outside) the region of enhanced precipitation. The net effect of the precipitation anomalies is to generate a zonal overturning cell which transports fresher surface water away from the forcing region and replaces it with cooler, more saline water from below.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Bryan F (1986) High-latitude salinity effects and interhemispheric thermohaline circulations. Nature 323:301–304
Bryan K (1969) A numerical method for the study of the circulation of the world ocean. J Comput Phys 4:347–376
Bryan K (1984) Accelerating the convergence to equilibrium of ocean climate models. J Phys Oceanogr 14:666–673
Bryden HL, Hall MM (1980) Heat transport by currents across 25°N latitude in the Atlantic Ocean. Science 207:884–886
Cooper NS (1988) The effect of salinity on tropical ocean models. J Phys Oceanogr 18:697–707
Cox MD (1984) A primitive equation, 3-dimensional model of the ocean. GFDL Ocean Group Tech. Rep. No. 1, GFDL/Princeton University, USA
Deser C, Wallace JM (1990) Large-scale atmospheric circulation features of warm and cold episodes in the tropical Pacific. J Clim 3:1254–1281
Esbensen SK, Kushnir V (1981) The heat budget of the global ocean: an atlas based on estimates from surface marine observations. Climatic Research Institute, Oregon State University, Corvallis, Rep. 29
Gill AE (1982) Atmosphere-ocean dynamics. Academic Press, San Diego, USA
Hellerman S, Rosenstein M (1983) Normal monthly mean windstress and windstress curl fields over the world ocean with error estimates. J Phys Oceanogr 13:1093–1104
Hough SS (1897) On the application of harmonic analysis to the dynamical theory of the tides. Part I. On Laplace's `oscillation of the first species', and on the dynamics of ocean currents. Phil Trans R Soc London Ser A 189:201–257
Jaeger L (1976) Monthly precipitation maps for the entire earth (in German). Ber Dtsch Wetterdienstes 18
Kiladis GN, van Loon H (1988) The Southern Oscillation. Part VII: Meteorological anomalies over the Indian and Pacific sectors associated with the extremes of the oscillation. Mon Wea Rev 116:120–136
Killworth PD (1983) Deep convection in the world ocean. Rev Geophys Space Phys 21:1–26
Levitus S (1982) Climatological Atlas of the World Ocean. NOAA Prof Pap No. 13, US Govt Printing Office, USA
Manabe S, Stouffer RJ (1988) Two stable equilibria of a coupled ocean-atmosphere model. J Clim 1:841–866
Meehl GA (1987) The annual cycle and interannual variability in the tropical Pacific and Indian Ocean regions. Mon Wea Rev 115:27–50
Moore DW, Philander SGH (1977) Modelling of the tropical ocean circulation. In: Goldberg ED, McCave IN, O'Brien JJ, Steele JH (eds) The Sea Vol 6. Wiley (Interscience), New York, pp 319–362
Nicholls N (1988) More on early ENSOs: evidence from Australian documentary sources. Bull Amer Met Soc 69:4–6
Philander SGH (1990) El Nino, La Nina, and the Southern Oscillation. Academic Press, San Diego, USA
Rasmusson EM, Wallace JM (1983) Meteorological aspects of the El Nino/Southern Oscillation. Science 222:1195–1202
Ropelewski CF, Halpert MS (1987) Global and regional scale precipitation associated with El Nino/Southern Oscillation. Mon Wea Rev 115:1606–1626
Weaver AJ, Sarachik ES (1991) The role of mixed boundary conditions in numerical models of the ocean's climate. J Phys Oceanogr 21:1470–1493
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Reason, C.J.C. On the effect of ENSO precipitation anomalies in a global ocean GCM. Climate Dynamics 8, 39–47 (1992). https://doi.org/10.1007/BF00209342
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00209342