Cirrus detrainment-temperature feedback

Citation
C. Chou et Jd. Neelin, Cirrus detrainment-temperature feedback, GEOPHYS R L, 26(9), 1999, pp. 1295-1298
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
GEOPHYSICAL RESEARCH LETTERS
ISSN journal
0094-8276 → ACNP
Volume
26
Issue
9
Year of publication
1999
Pages
1295 - 1298
Database
ISI
SICI code
0094-8276(19990501)26:9<1295:CDF>2.0.ZU;2-K
Abstract
In considering the role of cirriform clouds in climate change, it is import ant to distinguish among the relationships of different high cloud types to large-scale atmospheric dynamics. While cirrostratus and cirrocumulus (CsC c) have a clear relation to deep convective sources, the ensemble behavior of cirrus is more subtle. An empirical relation is found between cirrus fra ction and deep cloud top temperature that points to detrainment temperature as a dominant factor governing tropical and subtropical cirrus. This cirru s-detrainment-temperature (CDT) relation provides a target for modelers, an d suggests an additional cloud-climate feedback. As surface temperatures wa rm, detrainment temperatures cool as deep cloud top height increases. The C DT relation implies that cirrus fraction increases. Because cirrus are opti cally thinner than CsCc, the competition between longwave feedbacks and clo ud albedo feedbacks leads to a hypothesized positive climate feedback by ci rrus fraction.