Annual cycle of radiation fluxes over the Arctic ocean: Sensitivity to cloud optical properties

Journal Article · Sun Nov 01 00:00:00 EST 1992 · Journal of Climate; (United States)

DOI:https://doi.org/10.1175/1520-0442(1992)005<1267:ACORFO>2.0.CO;2· OSTI ID:6659897

Curry, J A ^[1]; Ebert, E E ^[2]

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1. Univ. of Colorado, Boulder (United States)
2. Bureau of Meteorology Research Centre, Melbourne (Australia)

The relationship between cloud optical properties and the radiative fluxes over the Arctic Ocean is explored by conducting a series of modeling experiments. The annual cycle of arctic cloud optical properties that are required to reproduce both the outgoing radiative fluxes at the top of the atmosphere as determined from satellite observations and the available determinations of surface radiative fluxes are derived. Existing data on cloud fraction and cloud microphysical properties are utilized. Four types of cloud are considered: low stratus clouds, midlevel clouds, citrus clouds, and wintertime ice crystal precipitation. Internally consistent annual cycles of surface temperature, surface albedo, cloud fraction and cloud optical properties, components of surface and top of atmosphere radiative fluxes, and cloud radiative forcing are presented. The modeled total cloud optical depth (weighted by cloud fraction) ranges from a low value in winter of 2 to a high summertime value of 8. Infrared emmissivities for liquid water clouds are shown to be substantially less than unity during the cold half of the year. Values of modeled surface cloud radiative forcing are positive except for two weeks in midsummer; over the course of the year clouds have a net warming effect on the surface in the Arctic. Total cloud radiative forcing at the top of the atmosphere is determined to be positive only briefly in early autumn. Surface longwave fluxes are shown to be very sensitive to the presence of lower-tropospheric ice crystal precipitation during the cold half of the year.

• OSTI ID: 6659897
• Journal Information: Journal of Climate; (United States), Vol. 5:11; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ARCTIC REGIONS
RADIATION FLUX
CLOUDS
OPTICAL PROPERTIES
ANNUAL VARIATIONS
FUNCTIONAL MODELS
ALBEDO
ARCTIC OCEAN
ATMOSPHERIC CIRCULATION
CLOUD COVER
ICE
PRECIPITATION
SATELLITES
SEASONAL VARIATIONS
PHYSICAL PROPERTIES
POLAR REGIONS
SEAS
SEPARATION PROCESSES
SURFACE WATERS
VARIATIONS
540110*