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Heng Xiao and Carlos R. Mechoso

for effects by seasonal variations in other features of the upper-ocean circulation (e.g., the thermocline) and GCMs capable of producing a realistic seasonal cycle in the upper ocean have been used to explore the interactions between ENSO and the seasonal cycle in the upper ocean (e.g., Chang et al. 1995 ; Guilyardi 2006 ). An and Wang (2001) , for example, working with a modified Cane–Zebiak model, found that allowing the basic state thermocline depth (upper-layer depth) to vary seasonally

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Gang Chen and Lantao Sun

hemispheres. A zonally symmetric version of the same model is used to diagnose the effects of different wavenumbers and different regions of the total forcing on the tropical stratospheric upwelling. Despite its simplicity, the model can simulate a reasonable seasonal cycle in the tropical upwelling in the lower stratosphere with a stronger amplitude during January (NH winter) than during July (NH summer), corroborating the importance of stratospheric planetary waves in the observed seasonal cycle of

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R. K. Scott

, nonlinearity, and the transient interaction of the seasonal cycle with the forcing. The latter is represented by the term J in (1) , which is nonzero if there is time correlation between the transience of the angular momentum distribution (forced by the seasonal cycle in the radiative basic state) and the unsteady meridional circulation response to time varying mechanical forcing. To investigate these effects, we first use a model in which the waves are explicitly resolved, the zonal momentum force

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Peter H. Stone and Dennis A. Miller

). In any case, the latitudinal trendin the seasonal changes in vertical extent is consistent with stronger/3 effects and increased valuesof n in lower latitudes. Since the fits at different latitudes are significantlydifferent, we present the best fits for two latitudestypical of the different types of behavior, 30 and50-N. The best fits for the transient eddy flux ofsensible heat at 30-N areF = 3.99(AT~ooo)~'4~ X 10x- W,(12)F = 1.07(AT~ooo - 8.65 K) x I-P4 W. (13)The observations are compared

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Alan Robock

earlier energy-balance models did notinclude these sophisticated effects, and this, it will beshown, contributed to their high sensitivity. In the next section the new'surface albedo parameterization is described. Then, model experiments arepresented which show the effects of the different components of the area and meltwater feedbacks onglobal sensitivity and the latitudinal and seasonal pattern of sensitivity. Finally, the implications of theseresults are discussed. An Appendix describes

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Charles McLandress

-part set of papers, the extended CMAM is used to investigate the seasonal variation of the propagating diurnal tide in the MLT region. After a short description of the model ( section 2 ), a comparison with UARS observations is made, and the general features of the simulated tide are characterized ( section 3a ). A detailed analysis of the terms in the diurnal tide momentum and thermodynamic budgets is then presented. This includes a discussion of the effects of the physical parameterizations, which

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Pragallva Barpanda and Tiffany Shaw

(increased SST with fixed CO 2 ) contributions. Seasonal and ENSO shifts were quantified using NCEP reanalysis and ERA-Interim data whereas shifts in response to increased CO 2 were quantified using the MPI AGCM. Changes in net energy are a small contribution across the time scales considered. Stationary eddies are the dominant contribution to storm-track shifts in response to seasonal insolation in the NH, El Niño minus La Niña conditions during NH winter, and direct and indirect effects of increased

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R. L. Walterscheid and J. G. DeVore

withobservations of the present study over earlier classical studies with respect to wavelengths in the region80-115 km is due primarily to the present heating rates rather than nonclassical effects; 2) with presentheating rates there is no phase shift below 30 km as predicted by the earlier classical model; 3) withoutnonclassical effects the amplitude of the barometric tide is significantly underpredicted; 4) the solutionswith nonclassical effects do not reproduce the rather large observed seasonal

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William R. Boos and Kerry A. Emanuel

shallow mixed layers, but WISHE will be largely eliminated for surfaces with such small heat capacities. In other words, monsoons are traditionally thought to exist because a land surface with a low heat capacity lies poleward of an ocean surface with a large heat capacity, and we expect such a configuration to be necessary for assessing the effects of interactive SST on WISHE in the Hadley circulation. This task is left for future work. c. Seasonally varying forcing How does WISHE alter the seasonal

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Syukuro Manabe and J. D. Mahlman

, based upon detailed budget analyses of angular momentum, heat andeddy kinetic energy. It is found that, with the exception of the high-latitude regions, the seasonal variationof temperature in the lower model stratosphere is essentially controlled by dynamical effects rather than bythe seasonM variation of local heating due to solar radiation. The stratosphere as simulated by the global model has large interhemispheric asymmetries in the shape ofthe polar westerly vortex, the magnitudes and the

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