Seasonal variation of surface and atmospheric cloud radiative forcing over the globe derived from satellite data

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/93JD01533· OSTI ID:53372

Gupta, S K; Staylor, W F; Darnell, W L; Wilber, A C; Ritchey, N A ^[1]

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1. Lockheed Engineering and Sciences Company, Hampton, VA (United States)

Global distributions of surface and atmospheric cloud radiative forcing parameters have been derived using parameterized radiation models with satellite meteorological data from the International Satellite Cloud Climatology Project, and directly measured top-of-atmosphere radiative fluxes from the Earth Radiation Budget Experiment. Specifically, shortwave, longwave, and total cloud forcing at the surface, and column-averaged values of longwave cloud forcing of the atmosphere were derived for the midseasonal months of April, July, and October 1985 and January 1986, covering a complete annual cycle. Seasonal variability is illustrated by comparing the results for July 1985 and January 1986, which represent the seasonal extremes. Surface shortwave cloud forcing is always negative, representing a cooling of the surface, with strongest cooling (-120 to -180 W/sq m) occurring over midlatitude storm tracks of the summer hemisphere. Surface longwave cloud forcing is always positive, representing a warming of the surface, with strongest warming (60 to 75 W/sq m) occurring over storm tracks of the winter hemisphere. Zonal averages show the entire summer hemisphere dominated by shortwave cooling, the middle and high latitudes of the winter hemisphere dominated by longwave warming, and a broad zone of transition in between. The globally averaged total cloud forcing amounts to a cooling throughout the year, ranging from a low of about -12 W/sq m for July 1985 to a high of about -25 W/sq m for January 1986. The longwave cloud forcing of the atmosphere shows a strong warming over deep convective regions in the tropics and a moderate cooling outside the tropics, amounting to a weak cooling (-2 to -5 W/sq m) in the global average.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center
• Sponsoring Organization: USDOE
• OSTI ID: 53372
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: D11 Vol. 98; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ANNUAL VARIATIONS
DATA ANALYSIS
EARTH ATMOSPHERE
RADIANT HEAT TRANSFER
REMOTE SENSING
TROPICAL REGIONS