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

  • ——, 1990: Low-frequency patterns induced by stationary waves. J. Atmos. Sci.,47, 629–648.

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

  • Geisler, J. E., M. L. Blackmon, G. T. Bates, and S. Muñoz, 1985: Sensitivity of January climate response to the magnitude and position of equatorial Pacific sea surface temperature anomalies. J. Atmos. Sci.,42, 1037–1049.

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

  • Hoerling, M. P., and A. Kumar, 1997: Why do North American climate anomalies differ from one El Niño event to another? Geophys. Res. Lett.,24, 1059–1062.

  • Horel, J. D., and J. M. Wallace, 1981: Planetary scale atmospheric phenomena associated with the Southern Oscillation. Mon. Wea. Rev.,109, 813–829.

  • Hoskins, B. J., and A. J. Simmons, 1975: A multi-layer spectral model and the semi-implicit method. Quart. J. Roy. Meteor. Soc.,101, 637–655.

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

  • Jin, F.-F., and B. J. Hoskins, 1995: The direct response to tropical heating in a baroclinic atmosphere. J. Atmos. Sci.,52, 307–319.

  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-year Reanalysis Project. Bull. Amer. Meteor. Soc.,77, 437–471.

  • Kumar, A., and M. P. Hoerling, 1997: Interpretation and implications of observed inter-El Niño variability. J. Climate,10, 83–91.

  • 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.

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

  • ——, J. M. Wallace, and G. Branstator, 1983: Barotropic wave propagation and instability and atmospheric teleconnection patterns. J. Atmos. Sci.,40, 1363–1392.

  • Ting, M., and I. M. Held, 1990: The stationary wave response to a tropical SST anomaly in an idealized GCM. J. Atmos. Sci.,47, 2546–2566.

  • ——, and M. P. Hoerling, 1993: Dynamics of stationary wave anomalies during the 1986/87 El Niño. Climate Dyn.,9, 147–164.

  • ——, and N.-C. Lau, 1993: A diagnostic and modeling study of the monthly mean wintertime anomalies appearing in a 100-year GCM experiment. J. Atmos. Sci.,50, 2845–2867.

  • ——, and P. D. Sardeshmukh, 1993: Factors determining the extratropical response to equatorial diabatic heating anomalies. J. Atmos. Sci.,50, 907–918.

  • Wallace, J. M., and D. S. Gutzler, 1981: Teleconnections in geopotential height field during the Northern Hemisphere winter. Mon. Wea. Rev.,109, 784–812.

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Editorial Type:
Article
Article Type:
Research Article

Steady Response to Tropical Heating in Wavy Linear and Nonlinear Baroclinic Models

Mingfang TingDepartment of Atmospheric Sciences, University of Illinois, Urbana–Champaign, Urbana, Illinois

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Linhai YuDepartment of Atmospheric Sciences, University of Illinois, Urbana–Champaign, Urbana, Illinois

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Print Publication:
01 Dec 1998
DOI:
https://doi.org/10.1175/1520-0469(1998)055<3565:SRTTHI>2.0.CO;2
Page(s):
3565–3582
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Abstract

The linear, steady-state, baroclinic model response to a tropical heating superimposed on a three-dimensional basic state is examined in this study. The emphasis is on the relevance of the linear model solution as compared to a fully nonlinear baroclinic model. The direct response to heating in the fully nonlinear, time-dependent model is obtained as the day-30 model response, following the Jin and Hoskins approach. When a 15-day linear damping is included in addition to Rayleigh friction, Newtonian cooling, and a scale-selective biharmonic diffusion, the comparison of the linear and the nonlinear model responses to a 2°C/day tropical heating reveals a striking similarity in both the spatial distribution and amplitude. Thus nonlinearity appears to be a secondary effect and may be crudely represented by the 15-day linear damping, and the linear steady-state model can be a useful tool in diagnostic studies.

Both the linear and the nonlinear model responses show an insensitivity to heating longitudes, especially when heating is located between 30°E and 120°W. This insensitivity is characterized by a geographically fixed response that consists of a streamfunction center over the central North Pacific and a weak wave train over the Pacific–North American region. The spatial structure of the preferred pattern does not depend on the dissipation or the amplitude of the tropical heating in the nonlinear model. The geographically fixed response is found to be prominent in the Northern Hemisphere for both the northern winter and summer climatological basic states.

Corresponding author address: Dr. Mingfang Ting, Department of Atmospheric Sciences, University of Illinois, Urbana–Champaign, 105 South Gregory Street, MC-233, Urbana, IL 61801.

Email: ting@uiuc.edu

Abstract

The linear, steady-state, baroclinic model response to a tropical heating superimposed on a three-dimensional basic state is examined in this study. The emphasis is on the relevance of the linear model solution as compared to a fully nonlinear baroclinic model. The direct response to heating in the fully nonlinear, time-dependent model is obtained as the day-30 model response, following the Jin and Hoskins approach. When a 15-day linear damping is included in addition to Rayleigh friction, Newtonian cooling, and a scale-selective biharmonic diffusion, the comparison of the linear and the nonlinear model responses to a 2°C/day tropical heating reveals a striking similarity in both the spatial distribution and amplitude. Thus nonlinearity appears to be a secondary effect and may be crudely represented by the 15-day linear damping, and the linear steady-state model can be a useful tool in diagnostic studies.

Both the linear and the nonlinear model responses show an insensitivity to heating longitudes, especially when heating is located between 30°E and 120°W. This insensitivity is characterized by a geographically fixed response that consists of a streamfunction center over the central North Pacific and a weak wave train over the Pacific–North American region. The spatial structure of the preferred pattern does not depend on the dissipation or the amplitude of the tropical heating in the nonlinear model. The geographically fixed response is found to be prominent in the Northern Hemisphere for both the northern winter and summer climatological basic states.

Corresponding author address: Dr. Mingfang Ting, Department of Atmospheric Sciences, University of Illinois, Urbana–Champaign, 105 South Gregory Street, MC-233, Urbana, IL 61801.

Email: ting@uiuc.edu

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