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1. Introduction The effects of precipitation on shallow convection have drawn much attention in recent years because of the desire to understand and quantify aerosol effects on clouds and climate. The conceptual framework for studies of this type follows a simple train of thought: Greater aerosol loading suppresses precipitation formation, increases cloud liquid water, and leads to longer-lived clouds and larger cloud fractions. Because the albedo effect of shallow clouds is greater than their
1. Introduction The effects of precipitation on shallow convection have drawn much attention in recent years because of the desire to understand and quantify aerosol effects on clouds and climate. The conceptual framework for studies of this type follows a simple train of thought: Greater aerosol loading suppresses precipitation formation, increases cloud liquid water, and leads to longer-lived clouds and larger cloud fractions. Because the albedo effect of shallow clouds is greater than their
1. Introduction One of the important goals of the National Aeronautics and Space Administration’s (NASA’s) Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE; Jensen et al. 2004 ) was to improve our understanding of the evolution of tropical anvil clouds generated by deep convective systems. In the tropics, anvil clouds comprised the majority of the cloud area exposed to the earth’s surface and to space ( Houze and Betts 1981 ). Since anvil
1. Introduction One of the important goals of the National Aeronautics and Space Administration’s (NASA’s) Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE; Jensen et al. 2004 ) was to improve our understanding of the evolution of tropical anvil clouds generated by deep convective systems. In the tropics, anvil clouds comprised the majority of the cloud area exposed to the earth’s surface and to space ( Houze and Betts 1981 ). Since anvil
about the vertical structure of clouds, which is equally crucial for model evaluation and development. The advent of the CloudSat satellite, launched in April 2006 ( Stephens et al. 2002 ), sheds light on the vertical structure of clouds globally for the first time. Most importantly, CloudSat carries a millimeter-wavelength cloud profiling radar, capable of penetrating thick clouds (e.g., cumulonimbus). Therefore, it is particularly useful for the research of convective clouds and has been used
about the vertical structure of clouds, which is equally crucial for model evaluation and development. The advent of the CloudSat satellite, launched in April 2006 ( Stephens et al. 2002 ), sheds light on the vertical structure of clouds globally for the first time. Most importantly, CloudSat carries a millimeter-wavelength cloud profiling radar, capable of penetrating thick clouds (e.g., cumulonimbus). Therefore, it is particularly useful for the research of convective clouds and has been used
1. Introduction Mesocale convective systems (MCSs) in the tropics connect the low atmospheric levels to the free troposphere, through the vertical transport of mass, water, and momentum. Their extended upper-level cloud decks have a strong impact on the tropical radiative budget (e.g., Ramanathan and Collins 1991 ; Machado and Rossow 1993 ; Wilcox and Ramanathan 2001 ; Del Genio and Kovari 2002 ; Roca et al. 2005b ; Del Genio et al. 2005 ). These convective systems also dominate the water
1. Introduction Mesocale convective systems (MCSs) in the tropics connect the low atmospheric levels to the free troposphere, through the vertical transport of mass, water, and momentum. Their extended upper-level cloud decks have a strong impact on the tropical radiative budget (e.g., Ramanathan and Collins 1991 ; Machado and Rossow 1993 ; Wilcox and Ramanathan 2001 ; Del Genio and Kovari 2002 ; Roca et al. 2005b ; Del Genio et al. 2005 ). These convective systems also dominate the water
1. Introduction Bands of anvil cirrus extending radially outward from regions of deep convection ( Fig. 1 ) are a common cloud characteristic near the outer edge of divergent upper-level outflows of mesoscale convective systems (MCSs). Lenz et al. (2009 , hereafter L09) document such banding events, lasting an average of 9 h, in approximately ½ of a sample of 136 large MCSs over the central United States during the 2006 warm season. L09 suggest the practical importance of these bands by
1. Introduction Bands of anvil cirrus extending radially outward from regions of deep convection ( Fig. 1 ) are a common cloud characteristic near the outer edge of divergent upper-level outflows of mesoscale convective systems (MCSs). Lenz et al. (2009 , hereafter L09) document such banding events, lasting an average of 9 h, in approximately ½ of a sample of 136 large MCSs over the central United States during the 2006 warm season. L09 suggest the practical importance of these bands by
1. Introduction The algorithm of Mecikalski and Bedka (2006) , which is referred to as the Satellite Convection Analysis and Tracking (S ATCA ST) system, demonstrates how the spatial, temporal, and spectral information from the Geostationary Operational Environmental Satellite (GOES; Menzel et al. 1998 ) meteorological satellite data can be used collectively to identify, track, and monitor growing convective clouds in their preconvective initiation state, to nowcast (0–1-h forecast
1. Introduction The algorithm of Mecikalski and Bedka (2006) , which is referred to as the Satellite Convection Analysis and Tracking (S ATCA ST) system, demonstrates how the spatial, temporal, and spectral information from the Geostationary Operational Environmental Satellite (GOES; Menzel et al. 1998 ) meteorological satellite data can be used collectively to identify, track, and monitor growing convective clouds in their preconvective initiation state, to nowcast (0–1-h forecast
casting the regulation of DCI in terms of individual parcels that the possible sensitivity of DCI to the environmental lapse rate of the active cloud-bearing layer can be considered. [The environmental lapse rate is defined as Γ = −∂ T 0 /∂ z , where T 0 is the environmental temperature, and the ACBL is defined as the layer above the LFC, that is, where “active” ( Stull 1985 ) deep convection occurs.] For parcels originating in the planetary boundary layer the increase in the LFC through dilution
casting the regulation of DCI in terms of individual parcels that the possible sensitivity of DCI to the environmental lapse rate of the active cloud-bearing layer can be considered. [The environmental lapse rate is defined as Γ = −∂ T 0 /∂ z , where T 0 is the environmental temperature, and the ACBL is defined as the layer above the LFC, that is, where “active” ( Stull 1985 ) deep convection occurs.] For parcels originating in the planetary boundary layer the increase in the LFC through dilution
1. Introduction The role of clouds remains one of the primary uncertainties in projections of future climates ( Bony et al. 2006 ; Solomon et al. 2007 ). Clouds and water vapor have a strong influence on the radiation budget of the earth, and it is unclear how cloud properties respond to global climate change. The tropics include half of the surface area of the earth, and account for much more than half of the earth’s greenhouse effect. Tropical deep convection is important in setting the
1. Introduction The role of clouds remains one of the primary uncertainties in projections of future climates ( Bony et al. 2006 ; Solomon et al. 2007 ). Clouds and water vapor have a strong influence on the radiation budget of the earth, and it is unclear how cloud properties respond to global climate change. The tropics include half of the surface area of the earth, and account for much more than half of the earth’s greenhouse effect. Tropical deep convection is important in setting the
1. Introduction Most diurnal cycles of cloud systems like dispersion of early fog, occurrence of cumuli after a sunny morning, or stormy weather at the end of the day are not well represented in general circulation models (GCMs). It is a concern for climate modeling because of the key role of clouds in the radiative and water budgets. Most GCMs underestimate middle and low clouds from shallow convection ( Zhang et al. 2005 ), while the radiative feedback associated with low-level clouds is a
1. Introduction Most diurnal cycles of cloud systems like dispersion of early fog, occurrence of cumuli after a sunny morning, or stormy weather at the end of the day are not well represented in general circulation models (GCMs). It is a concern for climate modeling because of the key role of clouds in the radiative and water budgets. Most GCMs underestimate middle and low clouds from shallow convection ( Zhang et al. 2005 ), while the radiative feedback associated with low-level clouds is a
1. Introduction Feedbacks in the climate system associated with clouds continue to be considered a major source of uncertainty in model projections of global warming ( Stephens 2005 ; Solomon et al. 2007 ). In particular, the tropics are associated with a large spectrum of cloud types, ranging from boundary layer clouds to deep convective clouds and anvils. Because of their different top altitudes and optical properties, the different cloud types affect the Earth’s radiation budget in various
1. Introduction Feedbacks in the climate system associated with clouds continue to be considered a major source of uncertainty in model projections of global warming ( Stephens 2005 ; Solomon et al. 2007 ). In particular, the tropics are associated with a large spectrum of cloud types, ranging from boundary layer clouds to deep convective clouds and anvils. Because of their different top altitudes and optical properties, the different cloud types affect the Earth’s radiation budget in various
