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1. Introduction The diabatic heating associated with tropical cloud systems is often considered a driver of large-scale circulations in the tropics and extratropics (e.g., Hartmann et al. 1984 ). Budget studies allow the computation of bulk heating profiles associated with the ensemble of tropical convection over large regions, typically a sounding network covering an area >100 000 km 2 (e.g., Reed and Recker 1971 ). However, it is much more difficult to observe the heating profile
1. Introduction The diabatic heating associated with tropical cloud systems is often considered a driver of large-scale circulations in the tropics and extratropics (e.g., Hartmann et al. 1984 ). Budget studies allow the computation of bulk heating profiles associated with the ensemble of tropical convection over large regions, typically a sounding network covering an area >100 000 km 2 (e.g., Reed and Recker 1971 ). However, it is much more difficult to observe the heating profile
1. Introduction Diabatic heating in the atmosphere is a combined consequence of radiative fluxes, phase changes of water substance, and turbulence flux of sensible heat from the earth’s surface. In the tropics, it is the major driving force of the atmospheric circulation. Through that, it acts as a unique cross-scale link between cloud microphysics and the global energy and water cycles. The importance of the vertical structure of diabatic heating cannot be overstated. The tropical atmospheric
1. Introduction Diabatic heating in the atmosphere is a combined consequence of radiative fluxes, phase changes of water substance, and turbulence flux of sensible heat from the earth’s surface. In the tropics, it is the major driving force of the atmospheric circulation. Through that, it acts as a unique cross-scale link between cloud microphysics and the global energy and water cycles. The importance of the vertical structure of diabatic heating cannot be overstated. The tropical atmospheric
1. Introduction Evaporation, transport, and condensation of water are critical processes through which the general circulation redistributes energy globally. Specifically, latent heat release drives winds that affect the transport of moisture and evaporation, and it shapes stability profiles and subsequent release of latent heat. These interactions are further complicated by the fact that the vertical structure of the heating is related to various microphysical processes in the life cycle of
1. Introduction Evaporation, transport, and condensation of water are critical processes through which the general circulation redistributes energy globally. Specifically, latent heat release drives winds that affect the transport of moisture and evaporation, and it shapes stability profiles and subsequent release of latent heat. These interactions are further complicated by the fact that the vertical structure of the heating is related to various microphysical processes in the life cycle of
of model resolution suggests that the mishandling of such interactions is not the chief culprit. The pointer thus turns toward the misrepresentation of diabatic processes, as manifested in errors of both the mean and transient diabatic heating. To some extent, a GCM’s mean diabatic heating error can be reduced by the (physical or unphysical) tuning of the GCM’s parameterizations. Errors in the variable heating are harder to tune away. Many transient atmospheric phenomena associated with strong
of model resolution suggests that the mishandling of such interactions is not the chief culprit. The pointer thus turns toward the misrepresentation of diabatic processes, as manifested in errors of both the mean and transient diabatic heating. To some extent, a GCM’s mean diabatic heating error can be reduced by the (physical or unphysical) tuning of the GCM’s parameterizations. Errors in the variable heating are harder to tune away. Many transient atmospheric phenomena associated with strong
1. Introduction The apparent heat source, Q 1 , is the heating that results from unresolved diabatic processes in the atmosphere, for example, cloud systems within a sounding network that spans a region on the order of 10 000 km 2 . Yanai et al. (1973) popularized the term as a way to relate large-scale motion and organized cumulus convection. The ability to characterize variations in Q 1 , especially its vertical structure, allows greater understanding of the relationship between tropical
1. Introduction The apparent heat source, Q 1 , is the heating that results from unresolved diabatic processes in the atmosphere, for example, cloud systems within a sounding network that spans a region on the order of 10 000 km 2 . Yanai et al. (1973) popularized the term as a way to relate large-scale motion and organized cumulus convection. The ability to characterize variations in Q 1 , especially its vertical structure, allows greater understanding of the relationship between tropical
1. Introduction To the first order, the atmospheric general circulation redistributes energy and balances the horizontal and vertical gradients of diabatic heating. Since the earth’s atmosphere is primarily heated from the surface, convective processes are required to maintain the troposphere close to neutral stratification. On the large scale, the heating gradient between the tropics and extratropics is balanced by the poleward transport of the heat of the general circulation. However, the
1. Introduction To the first order, the atmospheric general circulation redistributes energy and balances the horizontal and vertical gradients of diabatic heating. Since the earth’s atmosphere is primarily heated from the surface, convective processes are required to maintain the troposphere close to neutral stratification. On the large scale, the heating gradient between the tropics and extratropics is balanced by the poleward transport of the heat of the general circulation. However, the
1. Introduction The determination of the mean extratropical thermal structure is a longstanding problem in the general circulation of the atmosphere. The equilibrium extratropical climate arises from the competition between diabatic heating and dynamical transport, both players being in general a function of the time-dependent state vector. Yet while the heating is dominated by its linear part (one can get a good approximation to the mean heating using the mean temperature alone, at least in a
1. Introduction The determination of the mean extratropical thermal structure is a longstanding problem in the general circulation of the atmosphere. The equilibrium extratropical climate arises from the competition between diabatic heating and dynamical transport, both players being in general a function of the time-dependent state vector. Yet while the heating is dominated by its linear part (one can get a good approximation to the mean heating using the mean temperature alone, at least in a
1. Introduction In this paper we examine the linear response of a uniform horizontal temperature gradient to heating. Under certain assumptions on the vertical structure of the heating field, linear perturbations satisfy a modified form of surface quasigeostrophic dynamics. The system is the thermal analog to the Charney–Eliassen system of orographically forced barotropic Rossby waves ( Charney and Eliassen 1949 ; Held 1983 ) and a surface-only variant of the system studied by Smagorinsky
1. Introduction In this paper we examine the linear response of a uniform horizontal temperature gradient to heating. Under certain assumptions on the vertical structure of the heating field, linear perturbations satisfy a modified form of surface quasigeostrophic dynamics. The system is the thermal analog to the Charney–Eliassen system of orographically forced barotropic Rossby waves ( Charney and Eliassen 1949 ; Held 1983 ) and a surface-only variant of the system studied by Smagorinsky
congestus is also reported by Petty (1999) , utilizing surface synoptic reports together with infrared images of the Japanese fifth geostationary meteorological satellite ( GMS-5 ). He concluded that a substantial fraction (20%–40%) of precipitation comes from clouds warmer than 273 K in a large area to the east of Australia. Mapes (2000) also emphasized the significant role of cumulus congestus in helping to balance between the convective heating and atmospheric radiative cooling. Short and
congestus is also reported by Petty (1999) , utilizing surface synoptic reports together with infrared images of the Japanese fifth geostationary meteorological satellite ( GMS-5 ). He concluded that a substantial fraction (20%–40%) of precipitation comes from clouds warmer than 273 K in a large area to the east of Australia. Mapes (2000) also emphasized the significant role of cumulus congestus in helping to balance between the convective heating and atmospheric radiative cooling. Short and
). Estimating vertical profiles of latent heating released by precipitating cloud systems is one of the key objectives of TRMM, together with accurately measuring the horizontal distribution of tropical rainfall [see a review by Tao et al. (2006) ]. The PR is the first spaceborne precipitation radar and can provide height information based upon the time delay of the precipitation-backscattered return power. This allows for vertical profiles of precipitation to be obtained directly over the global Tropics
). Estimating vertical profiles of latent heating released by precipitating cloud systems is one of the key objectives of TRMM, together with accurately measuring the horizontal distribution of tropical rainfall [see a review by Tao et al. (2006) ]. The PR is the first spaceborne precipitation radar and can provide height information based upon the time delay of the precipitation-backscattered return power. This allows for vertical profiles of precipitation to be obtained directly over the global Tropics
