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Charles McLandress and Theodore G. Shepherd

, 40 – 57 . Manzini , E. , B. Steil , C. Brühl , M. A. Giorgetta , and K. Krüger , 2003 : A new interactive chemistry-climate model: 2. Sensitivity of the middle atmosphere to ozone depletion and increase in greenhouse gases and implications for recent stratospheric cooling. J. Geophys. Res. , 108 , 4429 . doi:10.1029/2002JD002977 . Matsuno , T. , 1970 : Vertical propagation of stationary planetary waves in the winter Northern Hemisphere. J. Atmos. Sci. , 27 , 871 – 883

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Isla R. Simpson, Theodore G. Shepherd, Peter Hitchcock, and John F. Scinocca

the eddy feedbacks in the December–February (DJF) season, which is when the bias is most severe, and then proceeds to examine the seasonal variation in eddy feedbacks. By quantifying the eddy feedback strength as a function of season and examining the contribution from different zonal scales, a more detailed understanding of the dynamics of SAM variability in the observed atmosphere is obtained. In particular, planetary-scale waves are found to provide a negative feedback on the SAM in the summer

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Xin Qu and Alex Hall

product of two terms, one representing the dependence of net incoming solar radiation on surface albedo (∂ Q /∂ α s ), and another representing the change in surface albedo induced by a unit temperature change (Δ α s /Δ T s ). The partial derivative, ∂ Q /∂ α s [first term in Eq. (1) ] can be rewritten as follows: where I t is the incoming solar radiation at the top of atmosphere (TOA), which we take to be a constant, and ∂ α p /∂ α s is the variation in planetary albedo with snow albedo, with

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Yun Yang, Lixin Wu, and Changfang Fang

decadal variability ( Stephenson et al. 2006 ). In this study, we will focus on the response of the decadal NAT to carbon dioxide (CO 2 ) increase using a coupled ocean–atmosphere general circulation model, and show that the global warming will suppress decadal variability of both the NAT and NAO. This suppression is likely associated with acceleration of oceanic planetary Rossby wave due to an increase of buoyancy frequency in global warming. The paper is arranged as follows. Section 2 gives a

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V. I. Fomichev, A. I. Jonsson, J. de Grandpré, S. R. Beagley, C. McLandress, K. Semeniuk, and T. G. Shepherd

1.22 ± 0.06 Tg s −1 in C2 from 7.36 ± 0.03 Tg s −1 in B1 (the range represents the standard error of the 30-yr dataset). This agrees well with the average increase of 1.1 ± 0.2 Tg s −1 found by Butchart et al. (2006) in a comparison of time slice and transient simulations from most of the current middle atmosphere GCMs. c. Planetary Rossby waves in the extratropical stratosphere A question of obvious importance to the stratospheric circulation and polar temperatures is the extent to which

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Riccardo Farneti and Geoffrey K. Vallis

) tendency and the zonally integrated surface flux, so that the oceanic meridional heat transport (OHT) is given by The total or planetary energy transport (PHT) is then If we assume that on sufficiently long time scales the total ocean heat content does not vary, the PHT may be computed from net radiation at the top of the atmosphere; if this is constant, then one subsystem must compensate for variations in another. However, such an argument cannot literally hold, for it is known that the total

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D. Rind, D. Shindell, P. Lonergan, and N. K. Balachandran

, planetary wave propagation, and position of tropospheric troughs and ridges. Rind et al. (1992) related lower-stratospheric volcanic warming to a reduction in the tropospheric Hadley circulation. Rind and Balachandran (1995) found that quasi-biennial oscillation (QBO) and UV variations impacted the troposphere in the Goddard Institute for Space Studies (GISS) Global Climate Middle Atmosphere Model (GCMAM) by changing tropospheric planetary wave generation and propagation. Kodera and Chiba (1995

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Bryan C. Weare

. Systematic differences of around 5% of themean are also evident between model climatological outgoing longwave at the top of the atmosphere and satelliteobservation. Model generated El Nifio anomalies of planetary albedo and outgoing longwave radiation generallyagree with observations as to position but underestimate magnitudes by up to a factor of 4. The potential musesand significance of these results are briefly discussed.1. Introduction In the past decade, general circulation models(GCMs) have

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Tiffany A. Shaw and Judith Perlwitz

using two lid height configurations: 10 and 0.5 hPa. They noted a large impact on planetary wave amplitude and phase throughout the depth of the atmosphere when they lowered the model lid. In particular the wave amplitude was very large in the vicinity of the model lid and the phase lines were tilted in the vertical. They argued that these changes were indications of increased wave reflection in the low-lid model. While Boville and Cheng (1988) considered the impact of lid height on the structural

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Kyle L. Swanson

1. Introduction The climatological zonal asymmetries in the atmosphere result from asymmetries at the earth's surface. Averaged over sufficiently long timescales, the combined forcing by topography and zonally asymmetric diabatic heating yields the stationary planetary waves that underlie regional climate variations in the extratropics (cf. the reviews by Held 1983 ; Held et al. 2002 ). However, superposed on this stationary planetary wave structure is a vigorous spectrum of low

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