This study will assess the structure and radiative heating processes in large, long lasting cirriform clouds produced by mesoscale convective cloud systems (MCSs) and the impacts of this heating on the larger-scale circulation. The A-Train satellites CloudSat and CALIPSO will be the primary data sources for the study. Objective 1 is case-by-case analysis of the cirriform clouds of MCSs. MCSs in the path of the A-train satellites will be identified through analysis of data from Aqua and other satellites. The cloud radar and lidar data from CloudSat and CALIPSO will be ingested into the Zebra visualization tool to analyze the horizontal dimensions, anvil base and top heights, and the distribution of radar reflectivity and lidar backscattering within the cirriform clouds of MCSs, including both precipitating clouds and non-precipitating anvils. Objective 2 is statistical compilation of the MCS ice-cloud characteristics obtained under Objective 1. The results will be grouped by region, season, and type of MCS in the form of frequency distributions representing the spatial dimensions and ice water content of the anvils. The cloud radar and cloud lidar data will be converted to ice water content by the best available algorithms. Objective 3 is to compute the radiative heating by the non-precipitating and precipitating ice clouds of MCSs. The Fu-Liou radiative transfer code will be applied to the observed cirriform cloud structures analyzed under Objectives 1 and 2 to obtain a set of radiative heating profiles that apply generally to MCSs, including their non-precipitating anvils. Objective 4 is to assess the global circulation's response to the radiative heating in cirriform clouds produced by MCSs. The heating profiles derived under Objective 3 will be applied in a simplified climate model to determine the response of the large-scale circulation to the radiative heating occurring in non-precipitating MCS anvils. The response of the large-scale circulation to the non-precipitating anvils will be compared to the large-scale response to latent heating and cooling and radiation in the raining parts of MCSs. Relevance: This research directly addresses the goals of the NASA A-Train satellite program, which aims to evaluate quantitatively the representation of clouds and cloud processes in global atmospheric circulation models, especially in terms of the radiative heating by clouds. Quantifying these processes is essential to the progress of NASA earth system research.
