The nonlinear relationship between albedo and cloud fraction on near-global, monthly mean scale in observations and in the CMIP5 model ensemble
2015 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 42, no 21, 9571-9578 p.Article in journal (Refereed) Published
We study the relation between monthly mean albedo and cloud fraction over ocean,60∘S–60∘N. Satellite obser vations indicate that these clouds all fall on the same near-exponential curve,with a monotonic distribution over the ranges of cloud fractions and albedo. Using these observational dataas a reference, we examine the degree to which 26 climate models capture this feature of the near-globalmarine cloud population. Models show a general increase in albedo with increasing cloud fraction, but noneof them display a relation that is as well deﬁned as that characterizing the observations. Models t ypicallydisplay larger albedo variability at a given cloud fraction, larger sensitivity in albedo to changes in cloudfraction, and lower cloud fractions. Several models also show branched distributions, contrasting with thesmooth observational relation. In the models the present-day cloud scenes are more reﬂective than thepreindustrial, demonstrating the simulated impact of anthropogenic aerosols on planetary albedo.
Place, publisher, year, edition, pages
2015. Vol. 42, no 21, 9571-9578 p.
Meteorology and Atmospheric Sciences
IdentifiersURN: urn:nbn:se:su:diva-125299DOI: 10.1002/2015GL066275ISI: 000368336800098OAI: oai:DiVA.org:su-125299DiVA: diva2:892350