• Barnett, T. P., M. Latiff, N. Graham, M. Flugel, S. Pazian, and W. White, 1993: ENSO and ENSO-related predictability. Part I: Prediction of equatorial Pacific sea surface temperatures with a hybrid coupled ocean–atmosphere model. J. Climate,6, 1545–1566.

  • Bell, T. L., 1985: Climate sensitivity and fluctuation-dissipation relations. Turbulence and Predictability in Geophysical Fluid Dynamics and Climate Dynamics, International School of Physics, 424–440.

  • Blackmon, M. L., J. E. Geisler, and E. J. Pitcher, 1983: A general circulation model study of January climate anomaly patterns associated with interannual variation of equatorial Pacific sea surface temperature. J. Atmos. Sci.,40, 1410–1425.

  • Branstator, G., 1983: Horizontal energy propagation in a baroclinic atmosphere with meridional and zonal structure. J. Atmos. Sci.,7, 1689–1708.

  • ——, 1985: Analysis of general circulation model sea-surface temperature anomaly simulations using a linear model. Part I: Forced solutions. J. Atmos. Sci.,42, 2225–2241.

  • ——, 1992: The maintenance of low-frequency atmospheric anomalies. J. Atmos. Sci.,49, 1924–1945.

  • ——, 1995: Organization of storm track anomalies by recurring low-frequency circulation anomalies. J. Atmos. Sci.,52, 207–226.

  • Charney, J. G., and A. Eliassen, 1949: A numerical method for predicting the perturbation of the middle-latitute westerlies. Tellus,1, 38–54.

  • Davey, M. K., S. Ineson, and M. A. Balmaseda, 1994: Simulation and hindcasts of tropical Pacific Ocean interannual variability. Tellus,46A, 433–447.

  • DelSole, T., 1996: Can quasigeostrophic turbulence be modeled stochastically? J. Atmos. Sci.,11, 1617–1633.

  • Gill, A. E., 1980: Some simple solutions for heat induced tropical circulation. Quart. J. Roy. Meteor. Soc.,106, 447–462.

  • Hasselman, K., 1988: PIPs and POPs: The reduction of complex dynamical systems using principal interaction and oscillation patterns. J. Geophys. Res.,93, 1015–1021.

  • Held, I. M., and I.-S. Kang, 1987: Barotropic models of the extratropical response to El Niño. J. Atmos. Sci.,44, 3576–3586.

  • ——, S. W. Lyons, and S. Nigam, 1989: Transients and the extratropical response to El Niño. J. Atmos. Sci.,46, 163–174.

  • Hoerling, M. P., and M. Ting, 1994: Organization of extratropical transients during El Niño. J. Climate,7, 745–766.

  • Hoskins, B. J., and D. J. Karoly, 1981: The steady linear response of a spherical atmosphere to thermal and orographic forcing. J. Atmos. Sci.,38, 1179–1196.

  • ——, and T. Ambrizzi, 1993: Rossby wave propagation on a realistic longitudinally varying flow. J. Atmos. Sci.,50, 1661–1671.

  • ——, A. J. Simmons, and D. G. Andrews, 1977: Energy dispersion in a barotropic atmosphere. Quart. J. Roy. Meteor. Soc.,103, 553–568.

  • James, I. N., and P. M. James, 1992: Spatial structure of ultra-low-frequency variability of the flow in a simple atmospheric circulation model. Quart. J. Roy. Meteor. Soc.,118, 1211–1233.

  • Karoly, D., 1983: Rossby wave propagation in a barotropic atmosphere. Dyn. Atmos. Oceans,7, 111–125.

  • Kasahara, A., and P. L. da Silva Dias, 1986: Response of planetary waves to stationary tropical heating in a global atmosphere with meridional and vertical shear. J. Atmos. Sci.,43, 1893–1911.

  • Kok, C. J., and J. D. Opsteegh, 1985: On the possible causes of anomalies in seasonal mean circulation pattern during the 1982–83 El Niño event. J. Atmos. Sci.,42, 677–694.

  • Lau, N.-C., 1988: Variability of the observed midlatitude stormtracks in relation to low-frequency changes in the circulation pattern. J. Atmos. Sci.,45, 2718–2743.

  • Leith, C. E., 1975: Climate response and fluctuation dissipation. J. Atmos. Sci.,32, 2022–2026.

  • Lim, H., and C.-P. Chang, 1986: Dynamics of teleconnections and Walker circulations forced by equatorial heating. J. Atmos. Sci.,40, 1897–1915.

  • Lindzen, R., 1967: Planetary waves on beta-planes. Mon. Wea. Rev.,95, 441–451.

  • North, G. R., 1984: Empirical orthogonal functions and normal modes. J. Atmos. Sci.,41, 880–887.

  • ——, R. E. Bell, and J. W. Hardin, 1993: Fluctuation dissipation in a general circulation model. Climate Dyn.,8, 259–264.

  • Penland, C., 1989: Random forcing and forecasting using principal oscillation pattern analysis. Mon. Wea. Rev.,117, 2165–2185.

  • ——, and M. Ghil, 1993: Forecasting Northern Hemisphere 700 mb geopotential height anomalies using empirical normal modes. Mon. Wea. Rev.,121, 2355–2372.

  • ——, and T. Magorian, 1993: Prediction of NINO3 sea-surface temperatures using linear inverse modeling. J. Climate,8, 1067–1076.

  • Polyak, I., 1996: Observed versus simulated second-moment climate statistics in GCM verification problems. J. Atmos. Sci.,53, 677–694.

  • Sardeshmukh, P. D., and B. J. Hoskins, 1988: The generation of global rotational flow by steady idealized tropical divergence. J. Atmos. Sci.,45, 1228–1251.

  • Schneider, E. K., and I. G. Watterson, 1984: Stationary Rossby wave propagation through easterly layers. J. Atmos. Sci.,41, 2069–2083.

  • Simmons, A. J., 1982: The forcing of stationary wave motion by tropical diabatic heating. Quart. J. Roy. Meteor. Soc.,108, 503–534.

  • von Storch, H., and D. P. Baumhefner, 1991: Principal oscillation pattern analysis of the tropical 30- to 60-day oscillation. Part II:The prediction of equatorial velocity potential and its skill. Climate Dyn.,6, 1–12.

  • Webster, P. J., 1982: Seasonality in the local and remote atmospheric response to sea surface temperature anomalies. J. Atmos. Sci.,39, 41–52.

  • ——, and J. R. Holton, 1982: Cross equatorial response to middle latitude forcing in a zonally varying basic state. J. Atmos. Sci.,39, 722–733.

  • Williamson, D. L., 1983: Description of the NCAR Community Climate Model (CCM0B). NCAR Tech. Note, NCAR/TN-210+STR, 88 pp. [Available from National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307.].

  • Zebiak, S. E., and M. A. Cane, 1987: A model El Niño/Southern Oscillation. Mon. Wea. Rev.,115, 2262–2278.

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An Empirical Model of Barotropic Atmospheric Dynamics and Its Response to Tropical Forcing

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  • 1 National Center for Atmospheric Research,* Boulder, Colorado
  • | 2 Program in Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado
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Abstract

A linear empirical model of barotropic atmospheric dynamics is constructed in which the streamfunction tendency field is optimally predicted using the concurrent streamfunction state as a predictor. The prediction equations are those resulting from performing a linear regression between tendency and state vectors. Based on the formal analogy between this model and the linear nondivergent barotropic vorticity equation, this empirical model is applied to problems normally addressed with a conventional model based on physical principles. It is found to qualitatively represent the horizontal dispersion of energy and to skillfully predict how a general circulation model will respond to steady tropical heat sources. Analysis of model solutions indicates that the empirical model’s dynamics include processes that are not represented by conventional nondivergent linear models. Most significantly, the influence of internally generated midlatitude divergence anomalies and of anomalous vorticity fluxes by high-frequency transients associated with low-frequency anomalies are automatically incorporated into the empirical model. The results suggest the utility of empirical models of atmospheric dynamics in situations where estimates of the response to external forcing are needed or as a standard of comparison in efforts to make models based on physical principles more complete.

Corresponding author address: Dr. Grant Branstator, NCAR, P.O. Box 3000, Boulder, CO 80307-3000.

Abstract

A linear empirical model of barotropic atmospheric dynamics is constructed in which the streamfunction tendency field is optimally predicted using the concurrent streamfunction state as a predictor. The prediction equations are those resulting from performing a linear regression between tendency and state vectors. Based on the formal analogy between this model and the linear nondivergent barotropic vorticity equation, this empirical model is applied to problems normally addressed with a conventional model based on physical principles. It is found to qualitatively represent the horizontal dispersion of energy and to skillfully predict how a general circulation model will respond to steady tropical heat sources. Analysis of model solutions indicates that the empirical model’s dynamics include processes that are not represented by conventional nondivergent linear models. Most significantly, the influence of internally generated midlatitude divergence anomalies and of anomalous vorticity fluxes by high-frequency transients associated with low-frequency anomalies are automatically incorporated into the empirical model. The results suggest the utility of empirical models of atmospheric dynamics in situations where estimates of the response to external forcing are needed or as a standard of comparison in efforts to make models based on physical principles more complete.

Corresponding author address: Dr. Grant Branstator, NCAR, P.O. Box 3000, Boulder, CO 80307-3000.

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