Abstract
The effects of freshwater flux (FWF) on modulating ENSO have been of great interest in recent years. Large FWF bias is evident in Coupled General Circulation Models (CGCMs), especially over the tropical Pacific where large precipitation bias exists due to the so-called “double ITCZ” problem. By applying an empirical correction to FWF over the tropical Pacific, the sensitivity of ENSO variability is investigated using the new version (version 1.0) of the NCAR’s Community Earth System Model (CESM1.0), which tends to overestimate the interannual variability of ENSO accompanied by large FWF into the ocean. In response to a small adjustment of FWF, interannual variability in CESM1.0 is reduced significantly, with the amplitude of FWF being reduced due to the applied adjustment part whose sign is always opposite to that of the original FWF field. Furthermore, it is illustrated that the interannual variability of precipitation weakens as a response to the reduced interannual variability of SST. Process analysis indicates that the interannual variability of SST is damped through a reduced FWF-salt-density-mixing-SST feedback, and also through a reduced SST-wind-thermocline feedback. These results highlight the importance of FWF in modulating ENSO, and thus should be adequately taken into account to improve the simulation of FWF in order to reduce the bias of ENSO simulations by CESM.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Adler, R. F., and Coauthors, 2003: The version-2 Global Precipitation Climatology Project (GPCP) monthly precipitation analysis (1979-Present). Journal of Hydrometeorology, 4, 1147–1167.
Andersson, A., C. Klepp, K. Fennig, S. Bakan, H. Grassl, and J. Schulz, 2011: Evaluation of HOAPS-3 Ocean Surface Freshwater Flux Components. J. Appl. Meteor. Climatol., 50, 379–398, doi: 10. 1175/2010JAMC2341.1.
Barnett, T. P., N. Graham, S. Pazan, W. White, M. Latif, and M. Flügel, 1993: ENSO and ENSO-related predictability. Part I: Prediction of equatorial Pacific sea surface temperature with a hybrid coupled ocean-atmosphere model. J. Climate, 6, 1545–1566.
Bjerknes, J., 1969: Atmospheric teleconnections from the equatorial Pacific. Mon. Wea. Rev., 97, 163–172.
Cane, M. A., and S. E. Zebiak, 1985: A theory for El Niño and the southern oscillation. Science, 228, 1085–1087, doi: 10.1126/science.228.4703.1085.
Carton, J. A., 1991: Effect of seasonal surface freshwater flux on sea surface temperature in the tropical Atlantic ocean. J. Geophys. Res., 96, 12 593–12 598, doi: 10.1029/91JC01256.
Deser, C., A. Capotondi, R. Saravanan, and A. S. Phillips, 2006: Tropical Pacific and Atlantic climate variability in CCSM3. J. Climate, 19, 2451–2481, doi: 10.1175/JCLI3759.1.
Gent, P. R., and Coauthors, 2011: The community climate system model version 4. J. Climate, 24, 4973–4991, doi: 10.1175/2011JCLI4083.1.
Gettelman, A., and Coauthors, 2010: Global simulations of ice nucleation and ice supersaturation with an improved cloud scheme in the Community Atmosphere Model. J. Geophys. Res., 115, D18216, doi: 10.1029/2009JD013797.
Ham, S., and Coauthors, 2012: Effects of freshwater runoff on a tropical Pacific climate in the HadGEM2. Asia-Pacific Journal of Atmospheric Sciences, 48, 457–463.
Huang, B.Y., and V. M. Mehta, 2004: Response of the Indo-Pacific warm pool to interannual variations in net atmospheric freshwater. J. Geophys. Res., 109, C06022, doi: 10.1029/2003JC002114.
Hunke, E. C., and W. H. Lipscomb, 2008: CICE: The Los Alamos sea ice model user’s manual, version 4. Los Alamos National Laboratory Tech. Rep. LA-CC-06-012, 76 pp.
Hurrell, J. W., J. J. Hack, D. Shea, J. M. Caron, and J. Rosinski, 2008: A new sea surface temperature and sea ice boundary dataset for the community atmosphere model. J. Climate, 21, 5145–5153, doi: 10.1175/2008JCLI2292.1.
Kirtman, B. P., Y. Fan, and E. K. Schneider, 2002: The COLA global coupled and anomaly coupled ocean-atmosphere GCM. J. Climate, 15, 2301–2320.
Latif, M., and Coauthors, 1998: A review of the predictability and prediction of ENSO. J. Geophys. Res., 103, 14 375–14 393, doi: 10.1029/97JC03413.
Mechoso, C. R., and Coauthors, 1995: The seasonal cycle over the tropical Pacific in coupled ocean-atmosphere general circulation models. Mon. Wea. Rev., 123, 2825–2838.
Neale, R. B., and Coauthors, 2010: Description of the NCAR community atmosphere model (CAM 5.0). NCAR Tech. Note NCAR/TN-486+STR, 274 pp. [Available online at http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/description/cam5desc.pdf.]
Oleson, K. W., and Coauthors, 2010: Technical description of version 4.0 of the Community Land Model (CLM). NCAR Tech. Note NCAR/TN-478+STR, 257 pp.
Pan, X., B. Huang, and J. Shukla, 2011: Sensitivity of the tropical Pacific seasonal cycle and ENSO to changes in mean state induced by a surface heat flux adjustment in CCSM3. Climate Dyn., 37, 325–341.
Reason, C. J. C., 1992: On the effect of ENSO precipitation anomalies in a global ocean GCM. Climate Dyn., 8, 39–47, doi: 10.1007/BF00209342.
Rutt, I. C., M. Hagdorn, N. R. J. Hulton, and A. J. Payne, 2009: The Glimmer community ice sheet model. J. Geophys. Res., 114, F02004, doi: 10.1029/2008JF001015.
Schlosser, C. A., and P. R. Houser, 2007: Assessing a satellite-era perspective of the global water cycle. J. Climate, 20, 1316–1338.
Smith, R. D., and Coauthors, 2010: The Parallel Ocean Program (POP) reference manual. Los Alamos National Laboratory Tech. Rep. LAUR-10-01853, 140 pp.
Taylor, K. E., R. J. Stouffer, and G. A. Meehl, 2011: An overview of CMIP5 and the experiment design. Bull. Amer. Meteor. Soc., 93, 485–498, doi: 10.1175/BAMS-D-11-00094.1.
Wu, L., Y. Sun, J. Zhang, L. Zhang, and S. Minobe, 2010: Coupled ocean-atmosphere response to idealized freshwater forcing over the western tropical Pacific. J. Climate, 23, 1945–1954.
Yang, S., K. M. Lau, and P. S. Schopf, 1999: Sensitivity of the tropical Pacific ocean to precipitation-induced freshwater flux. Climate Dyn., 15, 737–750, doi: 10.1007/s003820050313.
Yu, L., and R. A. Weller, 2007: Objectively analyzed air-sea heat fluxes for the global ice-free oceans (1981-2005). Bull. Amer. Meteor. Soc., 88, 527–539, doi: 10.1175/BAMS-88-4-527.
Zhang, R.-H., and A. J. Busalacchi, 2008: Rectified effects of tropical instability wave (TIW)-induced atmospheric wind feedback in the tropical Pacific. Geophys. Res. Lett., 35, L05608, doi: 10.1029/2007GL033028.
Zhang, R.-H., and A. J. Busalacchi, 2009: Freshwater Flux (FWF)-Induced oceanic feedback in a hybrid coupled model of the tropical Pacific. J. Climate, 22, 853–879, doi: 10.1175/2008JCLI2543.1.
Zhang, R.-H., S. E. Zebiak, R. Kleeman, and N. Keenlyside, 2005: Retrospective El Niño forecasts using an improved intermediate coupled model. Mon. Wea. Rev., 133, 2777–2802, doi: 10.1175/MWR3000.1.
Zhang, R.-H., A. J. Busalacchi, X. Wang, J. Ballabrera-Poy, R. G. Murtugudde, E. C. Hackert, and D. Chen, 2009: Role of ocean biology-induced climate feedback in the modulation of El Niño-Southern Oscillation. Geophys. Res. Lett., 36, L03608, doi: 10.1029/2008GL036568.
Zhang, R.-H., G. Wang, D. Chen, A. J. Busalacchi, and E. C. Hackert, 2010: Interannual biases induced by freshwater flux and coupled feedback in the tropical Pacific. Mon. Wea. Rev., 138, 1715–1737.
Zhang, R.-H., F. Zheng, J. Zhu, Y. Pei, Q. Zheng, and Z. Wang, 2012: Modulation of El Niño-Southern Oscillation by freshwater flux and salinity variability in the Tropical Pacific. Adv. Atmos. Sci., 29, 647–660, doi: 10.1007/s00376-012-1235-4.
Zhang, R.-H., F. Zheng, J. Zhu, and Z. Wang, 2013: A successful real-time forecast of the 2010-11 La Niña event. Sci. Rep., 3, 1108, doi: 10.1038/srep01108.
Zheng, F., and R.-H. Zhang, 2012: Effects of interannual salinity variability and freshwater flux forcing on the development of the 2007/08 La Niña event diagnosed from Argo and satellite data. Dyn. Atmos. Oceans, 57, 45–57.
Zheng, F., R.-H. Zhang, and J. Zhu, 2014: Effects of interannual salinity variability on the barrier layer in the western-central equatorial Pacific: A diagnostic analysis from Argo. Adv. Atmos. Sci., 31(3), 532–542, doi: 10.1007/s00376-013-3061-8.
Zhu, J., B. Huang, M. A. Balmaseda, J. L. Kinter III, P. Peng, Z. -Z. Hu, and L. Marx, 2013: Improved reliability of ENSO hindcasts with multi-ocean analyses ensemble initialization. Climate Dyn., 41, 2785–2795, doi: 10.1007/s00382-013-1965-8.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kang, X., Huang, R., Wang, Z. et al. Sensitivity of ENSO variability to Pacific freshwater flux adjustment in the Community Earth System Model. Adv. Atmos. Sci. 31, 1009–1021 (2014). https://doi.org/10.1007/s00376-014-3232-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00376-014-3232-2