Impact of improved representation of horizontal and vertical cloud structure in a climate model
Impact of improved representation of horizontal and vertical cloud structure in a climate model
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气候模型中水平和垂直云结构改进表示的影响
DOI：
10.1007/s00382-011-1174-2
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发表时间：
2011
期刊：
影响因子：
4.6
通讯作者：
Shonk J
中科院分区：
文献类型：
--
作者：
Shonk J
许多研究调查了子网格云结构的误述可能对辐射预算产生的影响。在这项研究中，我们使用英国气象局统一模型的纯大气版本对当前气候进行了 20 年的模拟，以研究云近似对模型气候的影响。我们应用“三云”方案来表示水平云不均匀性和“指数随机”重叠，无论是单独还是组合，代替具有最大随机重叠的传统平面平行表示，到辐射方案中的云。比较了 20 年来辐射收支和其他气象变量的平均变化。参数化对大气层顶部短波和长波辐射预算的综合全局影响小于 1 W m−2，但在海洋层积云区域中发现了高达 10 W m−2 的变化。当表现出水平云不均匀性时，还可以识别出冬季极地地区近地表温度高达 3°C 的冷却，并且当实施指数随机重叠时，会发现类似幅度的变暖。纬向平均气温也有相同迹象的相应变化，热带对流层上层的最大变化可达0.5°C。该位置的纬向平均云分数变化符号相反，最大为 0.02。改善云结构的两个组成部分对对流层温度的单独影响与二氧化碳增加四倍所造成的变暖的约 2% 的程度相似。
Many studies have investigated the effects that misrepresentation of sub-grid cloud structure can have on the radiation budget. In this study, we perform 20-year simulations of the current climate using an atmosphere-only version of the Met Office Unified Model to investigate the effects of cloud approximation on model climate. We apply the “Tripleclouds” scheme for representing horizontal cloud inhomogeneity and “exponential-random” overlap, both separately and in combination, in place of a traditional plane-parallel representation with maximum-random overlap, to the clouds within the radiation scheme. The resulting changes to both the radiation budget and other meteorological variables, averaged over the 20 years, are compared. The combined global effect of the parameterizations on top-of-atmosphere short-wave and long-wave radiation budget is less than 1 W m−2, but changes of up to 10 W m−2are identified in marine stratocumulus regions. A cooling near the surface over the winter polar regions of up to 3°C is also identified when horizontal cloud inhomogeneity is represented, and a warming of similar magnitude is found when exponential-random overlap is implemented. Corresponding changes of the same sign are also found in zonally averaged temperature, with maximum changes in the upper tropical troposphere of up to 0.5°C. Changes in zonally averaged cloud fraction in this location were of opposite sign and up to 0.02. The individual effects on tropospheric temperature of improving the two components of cloud structure are of similar magnitudes to about 2% of the warming created by a quadrupling of carbon dioxide.
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影响因子：
--
作者：
H. Barker
通讯作者：
H. Barker
影响因子：
4.9
作者：
J. Shonk;R. Hogan
通讯作者：
J. Shonk;R. Hogan
影响因子：
8.9
作者：
J. Shonk;Robin J. Hogan
通讯作者：
J. Shonk;Robin J. Hogan
在多层一维太阳辐射传输算法中考虑亚网格规模的云变化
影响因子：
8.9
作者：
L. Oreopoulos;H. Barker
通讯作者：
H. Barker
极地反气旋的形成
DOI：
--
发表时间：
1937
期刊：
影响因子：
--
作者：
H. Wexler
通讯作者：
H. Wexler