JACCS Research Plan

Ground-based Cirrus Observations

Researchers:     S. Asano (Leader)
     (Radiation) A. Uchiyama, M. Fukabori, A. Yamazaki,
                 A. Yamamoto,Y. Takayama, M. Sasaki
 (Cloud Physics) M. Murakami, Y. Yamada, N. Orikasa, M. Miyao
    (Lidar, MRI) T. Nagai, T. Fujimoto, A. Ichiki
    (Lidar, CRL) T. Itabe, K. Mizutani
 (Wind-profiler) T. Kobayashi, A. Adachi

Objectives:

To obtain simultaneous observational data on cloud microphysical and radiative properties of high-level ice clouds from the ground, and to study the relationships between cloud microphysical properties and the radiative properties for cirrus and cirrostratus clouds associated with mid-latitude fronts.

Specific studies:

• Parameterization of cloud microphysical and radiative properties.
• Study of ice cloud formation processes.
• Verification of the radiative transfer models and satellite data.
• Development of new remote sensing methods to retrieve cloud parameters.
• Improvement of the instruments used for high-level ice cloud observations.

Researchers:     S. Asano (Leader)
     (Radiation) A. Uchiyama, Y. Mano, A. Yamazaki, M. Fukabori,
                 Y. Takayama
 (Cloud Physics) M. Murakami, N. Orikasa, M. Miyao, T. Tanaka

Objectives:

To obtain simultaneous observational data on cloud microphysical and macrophysical structures, and radiative properties for mid-latitude low- and mid-level stratiform clouds, and to study the relationships between the cloud structures and the radiative properties.

Specific studies:

• Effects of microphysical and macrophysical structures of stratus/stratocumulus clouds on cloud radiative properties and the solar radiation absorption.
• Statistics of cloud microphysical properties of mid-latitude water clouds.
• Cloud microphysical and radiative properties of mixed-phase (partially glaciated) clouds.
• Cloud microphysical and dynamical structures of the cloud-capped PBL over the warm Western-North Pacific Ocean.
• Development of new remote sensing techniques to retrieve cloud parameters.

Researchers:    S. Nakai (Leader)
                R. Kawamura

Objectives:

Satellite data analyses of regional-scale cloud activity over the western Pacific, to investigate the role of cloud in the heat and water budgets of the troposphere.

Specific studies:

• Estimation of cloud variations over multi-time scales.
• Investigation of tropical and mid-latitude cloud systems.
• Energy exchanges between mean flow and cloud disturbances.
• Cloud type classifications in meso scales.

Researchers:    T. Inoue (Leader)
                A. Uchiyama, K. Takahashi, Y. Mano, T. Ose

Objectives:

Analyses of various satellite data to infer global-scale distributions of cloudiness, and cloud and radiative properties, in order to study cloud-radiation interactions, and to validate climate models.

Specific studies:

1. Cloud climatology
   • Cloud type classification by means of the IR split window method (NOAA/AVHRR, GMS-5).
   • Temporal variations of cloud distributions (ISCCP data).
2. Cloud radiative forcing
   • Radiation budget analysis with cloud classifications (NOAA/AVHRR, ERBE).
   • Validation of (or comparison between) GCM performance (ERBE, ISCCP).
3. Cloud-parameter estimation
   • Algorithms to retrieve cloud top height, optical thickness, effective size and phase of cloud particles, cloud water content, and others (NOAA/AVHRR & HIRS, LANDSAT, DMSP/SSM-I, ADEOS).
   • Comparison (verification) of satellite data with the field observational data.

Researchers:    M. Yoshizaki (Leader)
                M. Ueno, H. Kamahori, A. Murata, J. Yoshimura,
                H. Seko, H. Eito, Y. Mano, A. Yamamoto

Objectives:

• To improve the capability of the MRI non-hydrostatic models to simulate large-scale cloud systems.
• To assess the effects of radiation, orography, and environmental conditions on the evolution of clouds and large-scale cloud systems.
• To improve our understanding of the interactions between cloud system and large-scale motions.
• To improve cloud parameterizations used in GCMs.

Targets:

• Mid-latitude, precipitating cloud system
• Tropical convective cloud system
• Cloud-capped PBL - stratus/stratocumulus over the warm, N-W Pacific Oceans

Researchers:    A. Uchiyama (Leader)
                T. Kobayashi, K. Masuda, K. Shibata, Y. Mano

Objectives:

Development of various computational models to study transfer processes of the solar and terrestrial radiation in realistic atmosphere-cloud-surface systems.

Specific studies:

1. Parameterization of the basic radiative transfer processes
   • Modeling of the single-scattering properties of nonspherical ice particles.
   • Parameterization of gaseous absorption in nonhomogeneous, scattering atmospheres.
2. Development of radiative transfer schemes
   • Practical 3-D models for inhomogeneous cloud fields.
   • Efficient computational models for observational data analyses.
   • Radiation schemes for cloud-dynamic models and GCMs.
3. Simulation studies
   • Verification of radiative transfer models which already have been developed.
   • Simulations of radiation field measured by field experiments.