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Title: Cloud-radiative forcing and climate: Results from the earth radiation budget experiment

Journal Article · · Science (Washington, D.C.); (USA)
;  [1];  [2]; ; ;  [3];  [4]
  1. Univ. of Chicago, IL (USA)
  2. State Univ. of New York, Stony Brook (USA)
  3. NASA Langley Research Center, Hampton, VA (USA)
  4. Univ. of Washington, Seattle (USA)

Quantitative estimates of the global distributions of cloud-radiative forcing have been obtained from the spaceborne Earth Radiation Budget Experiment (ERBE) launched in 1984. For the April 1985 period, the global shortwave cloud forcing ({minus}44.5 watts per square meter (W/m{sup 2})) due to the enhancement of planetary albedo, exceeded in magnitude the longwave cloud forcing (31.3 W/m{sup 2}) resulting from the greenhouse effect of clouds. Thus, clouds had a net cooling effect on the earth. This cooling effect is large over the mid- and high-latitude oceans, with values reaching {minus}100 W/m{sup 2}. The monthly averaged longwave cloud forcing reached maximum values of 50 to 100 W/m{sup 2} over the convectively disturbed regions of the tropics. However, this heating effect is nearly canceled by a correspondingly large negative short-wave cloud forcing, which indicates the delicately balanced state of the tropics. The size of the observed net cloud forcing is about four times as large as the expected value of radiative forcing from a doubling of CO{sub 2}. The shortwave and longwave components of cloud forcing are about ten times as large as those for a CO{sub 2} doubling. Hence, small changes in the cloud-radiative forcing fields can play a significant role as a climate feedback mechanism.

OSTI ID:
6372425
Journal Information:
Science (Washington, D.C.); (USA), Vol. 243:4887; ISSN 0036-8075
Country of Publication:
United States
Language:
English