An Evaluation of ENSO Asymmetry in the Community Climate System Models: A View from the Subsurface

Abstract The asymmetry between El Nino and La Nina is a key aspect of ENSO that needs to be simulated well by models in order to fully capture the role of ENSO in the climate system. Here the asymmetry between the two phases of ENSO in five successive versions of the Community Climate System Model (CCSM1, CCSM2, CCSM3 at T42 resolution, CCSM3 at T85 resolution, and the latest CCSM3 + NR, with the Neale and Richter convection scheme) is evaluated. Different from the previous studies, not only is the surface signature of ENSO asymmetry examined, but so too is its subsurface signature. By comparing the differences among these models as well as the differences between the models and the observations, an understanding of the causes of the ENSO asymmetry is sought. An underestimate of the ENSO asymmetry is noted in all of the models, but the latest version with the Neale and Richter scheme (CCSM3 + NR) is getting closer to the observations than the earlier versions. The net surface heat flux is found to damp th...

[1]  Steve Horstmeyer,et al.  El Niño, La Niña, and the Southern Oscillation , 2011 .

[2]  F. Sun,et al.  A 10–15-Yr Modulation Cycle of ENSO Intensity , 2009 .

[3]  Yongqiang Yu,et al.  Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations , 2009 .

[4]  R. Neale,et al.  The Impact of Convection on ENSO: From a Delayed Oscillator to a Series of Events , 2008 .

[5]  J. Carton,et al.  A Reanalysis of Ocean Climate Using Simple Ocean Data Assimilation (SODA) , 2008 .

[6]  J. Yu,et al.  A 10-15year Modulation Cycle of ENSO Intensity and its ENSO Asymmetry-Basic State Interaction Mechanism , 2007 .

[7]  Tao Zhang,et al.  Response of water vapor and clouds to El Niño warming in three National Center for Atmospheric Research atmospheric models , 2006 .

[8]  R. Burgman,et al.  A Simple Mechanism for ENSO Residuals and Asymmetry , 2006 .

[9]  W. Collins,et al.  The Formulation and Atmospheric Simulation of the Community Atmosphere Model Version 3 (CAM3) , 2006 .

[10]  P. Rasch,et al.  Representation of Clouds and Precipitation Processes in the Community Atmosphere Model Version 3 (CAM3) , 2006 .

[11]  W. Collins,et al.  The Community Climate System Model Version 3 (CCSM3) , 2006 .

[12]  Adam S. Phillips,et al.  Tropical Pacific and Atlantic Climate Variability in CCSM3 , 2006 .

[13]  James C. McWilliams,et al.  Diurnal Coupling in the Tropical Oceans of CCSM3 , 2006 .

[14]  James J. Hack,et al.  CCSM–CAM3 Climate Simulation Sensitivity to Changes in Horizontal Resolution , 2006 .

[15]  Tao Zhang,et al.  A regulatory effect of ENSO on the time‐mean thermal stratification of the equatorial upper ocean , 2006 .

[16]  A. Sterl,et al.  The ERA‐40 re‐analysis , 2005 .

[17]  Jong-Seong Kug,et al.  El Niño–La Niña Asymmetry in the Coupled Model Intercomparison Project Simulations* , 2005 .

[18]  James J. Hack,et al.  Radiative and Dynamical Feedbacks over the Equatorial Cold Tongue: Results from Nine Atmospheric GCMs , 2005 .

[19]  P. Rasch,et al.  Representation of Clouds and Precipitation Processes in the Community Atmosphere Model ( CAM 3 ) , 2005 .

[20]  G. Danabasoglu,et al.  The Community Climate System Model Version 4 , 2011 .

[21]  M. Latif,et al.  Tropical Pacific Decadal Variability and Its Relation to Decadal Modulations of ENSO , 2004 .

[22]  Tao Zhang,et al.  The Effect of Subtropical Cooling on the Amplitude of ENSO: A Numerical Study , 2004 .

[23]  L. Isaksen,et al.  The ERA-40 Reanalysis , 2004 .

[24]  David B. Stephenson,et al.  Probability-based methods for quantifying nonlinearity in the ENSO , 2003 .

[25]  Elizabeth C. Kent,et al.  Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century , 2003 .

[26]  W. Hsieh,et al.  Nonlinear modes of decadal and interannual variability of the subsurface thermal structure in the Pacific Ocean , 2003 .

[27]  A. Timmermann,et al.  Strong El Niño events and nonlinear dynamical heating , 2003 .

[28]  James J. Hack,et al.  A modified formulation of fractional stratiform condensation rate in the NCAR Community Atmospheric Model (CAM2) , 2003 .

[29]  De-Zheng Sun.  A Possible Effect of an Increase in the Warm-Pool SST on the Magnitude of El Niño Warming , 2003 .

[30]  David P. Edwards,et al.  An updated parameterization for infrared emission and absorption by water vapor in the National Center for Atmospheric Research Community Atmosphere Model , 2002 .

[31]  I. Kang,et al.  El Niño and La Niña sea surface temperature anomalies: Asymmetry characteristics associated with their wind stress anomalies , 2002 .

[32]  Michael J. McPhaden,et al.  Observations of Warm Water Volume Changes in the Equatorial Pacific and Their Relationship to El Niño and La Niña , 2000 .

[33]  James A. Carton,et al.  A Simple Ocean Data Assimilation Analysis of the Global Upper Ocean 1950–95. Part I: Methodology , 2000 .

[34]  David B. Stephenson,et al.  The “normality” of El Niño , 1999 .

[35]  Coordinated heat removal from the equatorial Pacific during the 1986–87 El Niño , 1998 .

[36]  Philip J. Rasch,et al.  A Comparison of the CCM3 Model Climate Using Diagnosed and Predicted Condensate Parameterizations , 1998 .

[37]  James J. Hack,et al.  Response of Climate Simulation to a New Convective Parameterization in the National Center for Atmospheric Research Community Climate Model (CCM3) , 1998 .

[38]  Frank O. Bryan,et al.  The NCAR Climate System Model Global Ocean Component , 1998 .

[39]  P. Gent,et al.  The NCAR Climate System Model, Version One* , 1998 .

[40]  Kevin E. Trenberth,et al.  The Definition of El Niño. , 1997 .

[41]  P. Xie,et al.  Global Precipitation: A 17-Year Monthly Analysis Based on Gauge Observations, Satellite Estimates, and Numerical Model Outputs , 1997 .

[42]  Min Zhong,et al.  El Niño, La Niña, and the Nonlinearity of Their Teleconnections , 1997 .

[43]  W. Large,et al.  Oceanic vertical mixing: a review and a model with a nonlocal boundary layer parameterization , 1994 .

[44]  J. Hack.  Parameterization of moist convection in the National Center for Atmospheric Research community climate model (CCM2) , 1994 .

[45]  R. C. Malone,et al.  Parallel ocean general circulation modeling , 1992 .

[46]  J. Wallace.  Effect of deep convection on the regulation of tropical sea surface temperature , 1992, Nature.

[47]  V. Ramanathan,et al.  Thermodynamic regulation of ocean warming by cirrus clouds deduced from observations of the 1987 El Niño , 1991, Nature.

[48]  P. Gent,et al.  Isopycnal mixing in ocean circulation models , 1990 .

[49]  Hilding Sundqvist,et al.  Parameterization of Condensation and Associated Clouds in Models for Weather Prediction and General Circulation Simulation , 1988 .

[50]  T. Barnett,et al.  Sea Surface Temperature, Surface Wind Divergence, and Convection over Tropical Oceans , 1987, Science.

[51]  M. Cane,et al.  A Model El Niñ–Southern Oscillation , 1987 .

[52]  S. Gadgil,et al.  Ocean–atmosphere coupling over monsoon regions , 1984, Nature.