Kentaroh Suzuki 교수

Abstract This study describes an approach for combining CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations to investigate the microphysical processes of warm clouds on the global scale. MODIS column optical thickness is vertically distributed between the cloud top and cloud bottom according to adiabatic and condensational growth assumptions and used as a vertical coordinate system to analyze profiles of CloudSat-observed radar reflectivity. The reflectivity

Abstract This study examines the warm rain formation process over the global ocean in global climate models. Methodologies developed to analyze CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations are employed to investigate the cloud-to-precipitation process of warm clouds and are applied to the model results to examine how the models represent the process for warm stratiform clouds. Despite a limitation of the present study that compares the statistics for

This study examines the validity of a tunable cloud parameter, the threshold particle radius triggering the warm rain formation, in a climate model. Alternate values of the model's particular parameter within uncertainty have been shown to produce severely different historical temperature trends due to differing magnitude of aerosol indirect forcing. Three different threshold radii are evaluated against satellite observations in terms of the statistics depicting microphysical process signatures

Abstract This study examines the warm rain formation process in global and regional cloud-resolving models. Methodologies developed to analyze CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations are employed to investigate the cloud-to-precipitation processes and are applied to model results for comparisons with corresponding statistics from the observations. Three precipitation categories of no precipitation, drizzle, and rain are defined according to nonat

We simulated the interactions of aerosols with liquid clouds using an aerosol‐coupled global cloud‐system‐resolving model with horizontal resolution of 7 km, and the results are compared with satellite observations of cloud and aerosols. The result shows detailed spatial structures of cloud droplet effective radii (CDR) realistically simulated especially over tropics. The global correlation statistics of liquid water path (LWP) with aerosol index (AI) are investigated for different cloud types t

Abstract This study evaluates 3‐D cloud effects on the radiation budget with a combined use of active sensor cloud profiling radar/CloudSat and imager Moderate Resolution Imaging Spectroradiometer/Aqua data on the A‐train. An algorithm is devised for constructing 3‐D cloud fields based on satellite‐observed cloud information. The 3‐D cloud fields thus constructed are used to calculate the broadband solar and thermal radiative fluxes with a 3‐D radiative transfer code developed by the authors. Th

Abstract This study investigates the correlation patterns between cloud droplet effective radius (CDR) and cloud optical thickness (COT) of warm clouds with a nonhydrostatic spectral bin microphysics cloud model. Numerical experiments are performed with the model to simulate low-level warm clouds. The results show a positive and negative correlation pattern between CDR and COT for nondrizzling and drizzling stages of cloud development, respectively, consistent with findings of previous observati

Abstract The cloud‐to‐precipitation transition process in warm clouds simulated by state‐of‐the‐art global climate models (GCMs), including both traditional climate models and a high‐resolution model, is evaluated against A‐Train satellite observations. The models and satellite observations are compared in the form of the statistics obtained from combined analysis of multiple‐satellite observables that probe signatures of the cloud‐to‐precipitation transition process. One common problem identifi

Abstract Impacts of absorbing and scattering aerosols on global energy balance are investigated with a global climate model. A series of sensitivity experiments perturbing emissions of black carbon and sulfate aerosols individually is conducted with the model to explore how components of global energy budget change in response to the instantaneous radiative forcing due to the two types of aerosols. It is demonstrated how differing vertical structures of the instantaneous radiative forcing betwee

The indirect effect of aerosols was simulated by a GCM for nonconvective water clouds and was compared with remote sensing results from the Advanced Very High Resolution Radiometer (AVHRR) satellite-borne sensor for January, April, July, and October of 1990. The simulated global distribution of cloud droplet radius showed a land–sea contrast and a characteristic feature along the coastal region similar to the AVHRR results, although cloud droplet radii from GCM calculations and AVHRR retrievals

This study demonstrates how aerosols influence the liquid precipitation formation process. This demonstration is provided by the combined use of satellite observations and global high‐resolution model simulations. Methodologies developed to examine the warm cloud microphysical processes are applied to both multi‐sensor satellite observations and aerosol‐coupled global cloud‐resolving model (GCRM) results to illustrate how the warm rain formation process is modulated under different aerosol condi

The layer‐mean radar reflectivity e observed by CloudSat and the columnar effective particle radius R e obtained from a combined microwave‐shortwave analysis are combined to investigate the joint relationships between e and R e for warm clouds. Global statistics for seasonally averaged data reveals that radar reflectivities e less than about −10 dBZ tend to relate to the effective radius via a sixth‐power dependency, corresponding to a constant number concentration implying that the condensation