SPARTICUS: Small Particles in Cirrus Science and Operations Plan

Mace, J. ; Jensen, E. ; McFarquhar, G. ; Comstock, J. ; Ackerman, T. ; Mitchell, D. ; Liu, X. ; Garrett, T.

Pacific Northwest National Laboratory

关键词: CLIMATES;    CLOUDS;    ECOSYSTEMS;    ENERGY BALANCE;    FEEDBACK;    GENERAL CIRCULATION MODELS;    HEATING;    RADIATIONS;    SENSITIVITY;    SOLAR ENERGY;    TROPOSPHERE;   

DOI  :  10.2172/971206
RP-ID  :  DOE/SC-ARM-10-003
PID  :  OSTI ID: 971206
Others  :  Other: PNNL-19141
Others  :  TRN: US201010%%222

学科分类：再生能源与代替技术

美国|英语

来源: SciTech Connect

【 摘 要 】

From a mass-weighted perspective, cirrus clouds exert an enormous influence on the radiative energy budget of the earth’s climate system. Owing to their location in the cold upper troposphere, cirrus can significantly reduce the outgoing longwave radiation while, at the same time, remaining relatively transmissive to solar energy. Thus, cirrus clouds are the only cloud genre that can exert a direct radiative warming influence on the climate system (Ackerman et al. 1988). It is not surprising, therefore, that general circulation models (GCMs) are especially sensitive to the presence of cirrus in the model atmosphere. Lohmann and Roeckner (1995), for instance, show that the climate sensitivity can vary by as much as 40% due to the properties of cirrus varying between transparent and opaque limits. Lohmann and Roeckner (1995) also identify a key feedback by cirrus that is often overlooked; on longer time scales cloud heating in the upper troposphere can act to maintain and modulate the general circulation of the atmosphere through accelerating the subtropical and polar jet streams. Understanding these mechanisms and representing them in models is complicated by the fact that cirrus properties vary over an enormous dynamic range compared to most other clouds.