Near-global survey of effective droplet radii in liquid water clouds using ISCCP data

Journal Article · Fri Apr 01 00:00:00 EST 1994 · Journal of Climate; (United States)

DOI:https://doi.org/10.1175/1520-0442(1994)007<0465:NGSOED>2.0.CO;2· OSTI ID:6709956

Han, Qingyan; Rossow, W B; Lacis, A B ^[1]

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1. South Dakota School of Mines and Technology, Rapid City, SD (United States) NASA Goddard, New York, NY (United States)

A global survey of cloud particle size variations can provide crucial constraints on how cloud processes determine cloud liquid water contents and their variation with temperature, and further, may indicate the magnitude of aerosol effects on clouds. A method, based on a complete radiative transfer model for Advanced Very High Resolution Radiometer (AVHRR)-measured radiances, is described for retrieving cloud particle radii in liquid water clouds from satellite data currently available from the International Satellite Cloud Climatology Project. Results of sensitivity tests and validation studies provide error estimates. AVHRR data from NOAA-9 and NOAA-10 have been analyzed for January, April, July and October in 1987 and 1988. The results of this first survey reveal systematic continental and maritime differences and hemispheric contrasts that are indicative of the effects of associated aerosol concentration differences: cloud droplet radii in continental water clouds are about 2-3 micrometers smaller than in marine clouds, and droplet radii are about 1 micrometer smaller in marine clouds of the Northern Hemisphere than in the Southern Hemisphere. The height dependencies of cloud droplet radii in continental and marine clouds are also consistent with differences in the vertical profiles of aerosol concentration. Significant seasonal and diurnal variations of effective droplet radii are also observed, particularly at lower latitudes. Variations of the relationship between cloud optical thickness and droplet radii may indicate variations in cloud microphysical regimes.

• OSTI ID: 6709956
• Journal Information: Journal of Climate; (United States), Vol. 7:4; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
PARTICLE SIZE
REMOTE SENSING
NORTHERN HEMISPHERE
TEMPERATURE DISTRIBUTION
SOUTHERN HEMISPHERE
ANNUAL VARIATIONS
RADIANT HEAT TRANSFER
COLLOIDS
DISPERSIONS
EARTH PLANET
ENERGY TRANSFER
HEAT TRANSFER
PLANETS
SIZE
SOLS
VARIATIONS
540110*
540310 - Environment
Aquatic- Basic Studies- (1990-)