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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 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
observations. In those algorithms, cloud types are inferred from the vertical structure of radar reflectivity and the associated profiles are obtained from cloud-resolving model simulations ( Shige et al. 2004 ; Tao et al. 2006 ). Another method of estimating latent heating profiles has been the use of in situ measurements of wind, pressure, and temperature using an array of soundings over a region to calculate the total diabatic heating Q 1 . In this approach, vertical velocity is first derived from
observations. In those algorithms, cloud types are inferred from the vertical structure of radar reflectivity and the associated profiles are obtained from cloud-resolving model simulations ( Shige et al. 2004 ; Tao et al. 2006 ). Another method of estimating latent heating profiles has been the use of in situ measurements of wind, pressure, and temperature using an array of soundings over a region to calculate the total diabatic heating Q 1 . In this approach, vertical velocity is first derived from
India during the active (break) phase. Additionally, a regional Walker circulation propagates eastward over the equatorial Indian Ocean. The space–time structures of precipitation, convection, and circulation in the leading MISO are somewhat better understood. In the tropics, the diabatic heating is the main source of energy that drives the atmospheric circulation, which in turn influences the diabatic heating through atmospheric instabilities. The tropical region receives two-thirds of the global
India during the active (break) phase. Additionally, a regional Walker circulation propagates eastward over the equatorial Indian Ocean. The space–time structures of precipitation, convection, and circulation in the leading MISO are somewhat better understood. In the tropics, the diabatic heating is the main source of energy that drives the atmospheric circulation, which in turn influences the diabatic heating through atmospheric instabilities. The tropical region receives two-thirds of the global
-third of the Tibetan Plateau (TP). Since the column-integrated diabatic heating over the SEALLH generally transitions from a heat sink to a heat source in March, one month earlier than over the Tibetan Plateau ( Fig. 2 ), the SEALLH are one of the earliest diabatic heating sources in the Asian summer monsoon region ( Chen and Li 1985 ). Fig . 1. (a) Location and (b) topography of the SEALLH. Fig . 2. Annual cycle of column-integrated diabatic heating over the SEALLH (W m −2 ). Values for TP
-third of the Tibetan Plateau (TP). Since the column-integrated diabatic heating over the SEALLH generally transitions from a heat sink to a heat source in March, one month earlier than over the Tibetan Plateau ( Fig. 2 ), the SEALLH are one of the earliest diabatic heating sources in the Asian summer monsoon region ( Chen and Li 1985 ). Fig . 1. (a) Location and (b) topography of the SEALLH. Fig . 2. Annual cycle of column-integrated diabatic heating over the SEALLH (W m −2 ). Values for TP
generation of A e ( G e ) ( Suomi and Shen 1963 ; Hansen and Nagle 1984 ). Neither the sign nor magnitude of G e is well determined because of insufficient space–time resolution of the conventional weather observations [ Oort and Peixoto (1983) , for instance, use monthly mean quantities]. Thus, G is not well quantified. Moreover, the residual calculation does not allow one to determine the separate contributions to G by the different diabatic heating processes, so these contributions have not
generation of A e ( G e ) ( Suomi and Shen 1963 ; Hansen and Nagle 1984 ). Neither the sign nor magnitude of G e is well determined because of insufficient space–time resolution of the conventional weather observations [ Oort and Peixoto (1983) , for instance, use monthly mean quantities]. Thus, G is not well quantified. Moreover, the residual calculation does not allow one to determine the separate contributions to G by the different diabatic heating processes, so these contributions have not
as a boundary forcing ( Charney and Shukla 1981 ) in a full atmosphere general circulation model (GCM; Wang et al. 2000 ; Lau and Nath 2000 ; Ju and Slingo 1995 ). Ashok et al. (2004) , Kucharski et al. (2007) , and Su et al. (2001) distinguished the atmosphere GCM response to the SST pattern in the 1997 event from the response to SST patterns for past El Niños, which were associated with a dry monsoon. However, in a full atmospheric GCM, the diabatic heating in the tropics may not respond
as a boundary forcing ( Charney and Shukla 1981 ) in a full atmosphere general circulation model (GCM; Wang et al. 2000 ; Lau and Nath 2000 ; Ju and Slingo 1995 ). Ashok et al. (2004) , Kucharski et al. (2007) , and Su et al. (2001) distinguished the atmosphere GCM response to the SST pattern in the 1997 event from the response to SST patterns for past El Niños, which were associated with a dry monsoon. However, in a full atmospheric GCM, the diabatic heating in the tropics may not respond
1. Introduction Tropical convective systems affect the large-scale circulation most effectively through diabatic heating due largely to latent heat release and, to a lesser degree, radiative effects. Here, “large-scale” refers to scales associated with synoptic disturbances and waves, the intraseasonal oscillation, and seasonally and interannually varying planetary-scale zonal (Walker) and meridional overturning circulations. Understanding vertical structures and evolution of diabatic heating
1. Introduction Tropical convective systems affect the large-scale circulation most effectively through diabatic heating due largely to latent heat release and, to a lesser degree, radiative effects. Here, “large-scale” refers to scales associated with synoptic disturbances and waves, the intraseasonal oscillation, and seasonally and interannually varying planetary-scale zonal (Walker) and meridional overturning circulations. Understanding vertical structures and evolution of diabatic heating
1. Introduction Diabatic heating is the ultimate energy source for driving the atmospheric circulation. In the tropics, latent heat release associated with deep convection is the dominant component of total diabatic heating. The heating induced large-scale circulation can further influence convection by modifying atmospheric instability through redistributing the localized latent heat and moisture or through dynamical lifting by low-level convergence. Because of this interactive process between
1. Introduction Diabatic heating is the ultimate energy source for driving the atmospheric circulation. In the tropics, latent heat release associated with deep convection is the dominant component of total diabatic heating. The heating induced large-scale circulation can further influence convection by modifying atmospheric instability through redistributing the localized latent heat and moisture or through dynamical lifting by low-level convergence. Because of this interactive process between
corresponding latent heat release from condensation, the physical process that dominates atmospheric diabatic heating. Large-scale persistent anomalies in diabatic heating, particularly over the tropical Indo-Pacific, are the physical drivers of global-scale teleconnections that can modulate the Indian monsoon circulation and rainfall. In the Pacific, ENSO-related diabatic heating and cooling force a Rossby wave response that alters the monsoon circulation (e.g., Jang and Straus 2012 , 2013 ). Over the
corresponding latent heat release from condensation, the physical process that dominates atmospheric diabatic heating. Large-scale persistent anomalies in diabatic heating, particularly over the tropical Indo-Pacific, are the physical drivers of global-scale teleconnections that can modulate the Indian monsoon circulation and rainfall. In the Pacific, ENSO-related diabatic heating and cooling force a Rossby wave response that alters the monsoon circulation (e.g., Jang and Straus 2012 , 2013 ). Over the
