Sensitivity of climate simulations to the parameterization of cumulus convection in the Canadian climate centre general circulation model
作者:
G.J. Zhang,
NormanA. McFarlane,
期刊:
Atmosphere-Ocean
(Taylor Available online 1995)
卷期:
Volume 33,
issue 3
页码: 407-446
ISSN:0705-5900
年代: 1995
DOI:10.1080/07055900.1995.9649539
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
A simplified cumulus parameterization scheme, suitable for use in GCMs, is presented. This parameterization is based on a plume ensemble concept similar to that originally proposed by Arakawa and Schubert (1974). However, it employs three assumptions which significantly simplify the formulation and implementation of the scheme. It is assumed that an ensemble of convective‐scale updrafts with associated saturated downdrafts may exist when the atmosphere is locally conditionally unstable in the lower troposphere. However, the updraft ensemble is comprised only of those plumes which are sufficiently buoyant to penetrate through this unstable layer. It is assumed that all such plumes have the same upward mass flux at the base of the convective layer. The third assumption is that moist convection, which occurs only when there is convective available potential energy (CAPE) for reversible ascent of an undiluted parcel from the sub‐cloud layer, acts to remove CAPE at an exponential rate with a specified adjustment time scale.
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