1.1 Current research fields (funded research):

    a. Satellite remote sensing of cloud properties
    b. Observational study of aerosol-cloud interactions
    c. Monitoring cloud formation and development

1.2 Research accomplishment

    a. First global survey of water cloud droplet size that shows contrast of droplet sizes between continental and maritime clouds and between two hemispheres (1994)
    b. First global survey of ice cloud properties (1997)
    c. First in indicating that effective particle size of 15 mm or larger retrieved by satellite data is indicative of drizzling (Han et al., 1995)
    d. First global survey of column number concentration of droplet in water clouds that can be used for model validations (1998)
    e. A global survey of the relationship between droplet size and cloud albedo suggests that cloud liquid water content should not be assumed as constant in model studies (1998)
    f. A model study shows that aspect ratio of ice crystal sizes have significant impact on single scattering properties and should be considered in retrieval of ice-cloud properties (1999)

Above results received 121 scientific citations in the most recent five years (1996-2000)

    g. First global survey of cloud column susceptibility reveals regions where aerosol-cloud interaction may cause cloud water to decrease (2000, in press)
    h. New algorithm developed to distinguish dust from cloud that can improve the study of aerosol-cloud interactions (2000, in writing)
    i. Improved algorithm for global survey of ice-cloud properties (2000, in writing)

1.3 New research fields under development:

    a. Study of clouds over polar regions (Proposal submitted to NASA)
    b. Model development for non-spherical particles (Proposal submitted to NSF)
    c. Ground observation to determine cloud vertical position (Supervising student thesis)
    d. Improving cloud prediction in MM5 (Supervising student thesis)

1.4 Science Teams Currently Involved:

    a. PI in the International Satellite Cloud Climatology Project (ISCCP)
    b. PI in the Global Aerosol Climatology Project (GACP)
    c. PI in the Global Imager Science Team (GLI, NASDA, Japan)
    d. PI in the Polarization and Directionality of the Earth's Reflectances I and II Science Teams (POLDER, CNES, France)
    e.Co-Investigator in the Cloud and the Earth's Radiant Energy System (CERES)
    f. Co-Investigator in the Tropical Rainfall Measurement Mission (TRMM)