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Steven L. Marcus, Olivier de Viron, and Jean O. Dickey

the atmosphere arise from two effects: frictional stresses at the land–atmosphere and ocean–atmosphere interfaces, and surface pressure gradients over mountains. In reality, of course, the earth has an elliptical cross section, with a dynamical oblateness of about 1/300. While the earth's oblateness has no direct impact on axial torques, the interaction of the surface pressure field with the earth's bulge produces equatorial torques given by where r is the radius vector from the earth's center

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Edwin K. Schneider, Richard S. Lindzen, and Ben P. Kirtman

precipitation in reality is not so clear, especially when cumulus clouds with small areal coverage are involved. There is indirect evidence that the model cloud parameterization may overemphasize the reduction of solar flux by cumulus ( Schneider et al. 1997 ), since removing the cumulus–radiative feedback greatly improves the simulation of tropical SST in a coupled ocean–atmosphere GCM. Over land, the latent heat flux from the ground also increases with the precipitation, due to increased ground wetness

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Shang-Ping Xie

coupled model develops an asymmetric state by itself. The basic-state winds of the atmosphere are basedon the COADS (Comprehensive Ocean-AtmosphericData Set), and the land grids are filled in the followingway. At latitudes where the North American continentfalls inside the model domain, we shift the COADSdata east of the central longitude (3, = 205- or 155-W)eastward so that the first COADS land grid is on theeastern boundary of the rectangular model ocean. Thisfills the land grids but leaves a

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William W. Kellogg

Science Foundation.0.15 or greater they cause a warming of the surfaceplus lower atmosphere; and since their sources aremostly the land surface, that is where most of themare to be found. If they lower the albedo of cloudtops, then they would tend to cause a warming in acloudy atmosphere as well. (Incidentally, taking theeffect of aerosols on infrared radiative flux intoaccount slightly enhances the warming influence,a point admittedly neglected by Charlock andSellers.) The reason Charlock and

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Robert G. Gallimore, Bette L. Otto-Bliesner, and John E. Kutzbach

assessing specific effects of parameterization indicate that decreased groundwetness and the modifications to the drag coefficient and moist convective adjustment produced most of themodel improvement in the global surface energy budget and hydrologic response. The results further imply asubstantial seasonal variation in sensitivity of the hydrologic interaction between land and ocean to changes insurface conditions. Major improvements in the simulation of the Asian monsoon during both seasons is

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Dehai Luo and Zhe Chen

role of deformation and potential vorticity in Southern Hemisphere blocking onsets. J. Atmos. Sci. , 62 , 4043 – 4056 . Hayashi , Y. , and D. G. Golder , 1987 : Effects of wave–wave and wave–mean flow interactions on the growth and maintenance of transient planetary waves in the presence of a mean thermal restoring force. J. Atmos. Sci. , 44 , 3392 – 3401 . Ji , L. R. , and S. Tibaldi , 1983 : Numerical simulations of a case of blocking: The effects of orography and land

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Masao Kanamitsu, T. N. Krishnamurti, and Colin Depradine

zonalflows, and thus have a strong stabilizing influence onthe mean zonal westerlies of the middle latitudes; 2)wavenumbers 5-10 and wavenumber 2 lose energy toother waves via wave-wave interactions; 3) Saltzmanattributes the behavior of wavenumber 2 (an energysource) due to land-ocean contrasts; and 4) the middlelatitude cyclone-scale waves (wavenumbers 5-10) loseenergy both to zonal and to waves via nonlinearbarotropic interactions. Yang's (1967) results utilizing multi-levels of dataover middle

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George Gutman

. REFERENCESBudyk0, M. I., 1974: Climate and Life, Academic Press, 508 pp.Gutman, G., G. Ohring and J. H. Joseph, 1984: Interaction between the geobotanic state and climate: A suggested approach and a test with a zonal model. J. Atmos. Sci., 41, 2663-2678. ., 1984: Numerical experiments on land surface alterations with a zonal model allowing for interaction between the geobotanic state and climate. J. Atmos. $ci., 41, 2679-2685.Sellers, W. D., 1965: Physical Climatology, University of Chicago Press, 272

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Nikki C. Privé and R. Alan Plumb

downward flux into the surface (THF) is prescribed as a function of latitude: where ϕ is the latitude, LHF is the latent heat flux into the atmosphere, SHF is the sensible heat flux into the atmosphere, and T s is the surface temperature. The surface temperature and heat fluxes are interdependent and calculated iteratively. Using a prescribed net radiative flux has the benefits of allowing direct control over the land surface forcing and of reducing the number of feedbacks, such as cloud radiative

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John E. Kutzbach and Peter J. Guetter

(due to albedo changes)provide an opportunity to compare and contrast thehemispheric-average response of surface energy andhydrologic budgets. (i) 9 kyr BP. For the Northern Hemisphere land,the imposed increase in solar radiation for July at thetop of the atmosphere was 39 W m-2. The increase innet solar radiation at the surface was 16 W m-t. Withthe warmer land surface and the associated warmingand increased moisture content of the atmosphere, thedownward-directed longwave radiation increased

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