Simulating weather regimes: impact of model resolution and stochastic parameterization
Simulating weather regimes: impact of model resolution and stochastic parameterization
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DOI：
10.1007/s00382-014-2238-x
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发表时间：
2015-04-01
期刊：
影响因子：
4.6
通讯作者：
Palmer, T. N.
中科院分区：
文献类型：
--
作者：
Dawson, Andrew;Palmer, T. N.
在政府间气候变化专门委员会第五次评估报告模拟中典型的具有水平分辨率的大气模型中模拟准持久性制度结构，被证明是不现实的。一个更高分辨率的配置相同的模式，水平分辨率的业务数值天气预报中使用的典型，能够模拟这些制度结构现实。在高分辨率下，模拟区域的空间模式非常准确。一个模型配置在中间分辨率显示了显着的改善，特别是在低分辨率配置的制度的时间特性方面，但不产生模拟准确的非常高的分辨率配置。它表明，制度的模拟可以显着改善，即使在低分辨率下，通过引入一个随机物理方案。在低分辨率的随机物理方案大大提高了空间和时间方面的制度模拟。这些结果突出了小尺度过程对大尺度气候变率的重要性，并表明，虽然模拟小尺度的变率是必要的，但为了改善大尺度气候的模拟，可能没有必要准确地甚至明确地表示小尺度。有人认为，这些结果可能有重要的影响，提高全球气候模拟，高分辨率有限区域模式的能力，低分辨率的全球模式，可靠地模拟区域气候变化信号。
The simulation of quasi-persistent regime structures in an atmospheric model with horizontal resolution typical of the Intergovernmental Panel on Climate Change fifth assessment report simulations, is shown to be unrealistic. A higher resolution configuration of the same model, with horizontal resolution typical of that used in operational numerical weather prediction, is able to simulate these regime structures realistically. The spatial patterns of the simulated regimes are remarkably accurate at high resolution. A model configuration at intermediate resolution shows a marked improvement over the low-resolution configuration, particularly in terms of the temporal characteristics of the regimes, but does not produce a simulation as accurate as the very-high-resolution configuration. It is demonstrated that the simulation of regimes can be significantly improved, even at low resolution, by the introduction of a stochastic physics scheme. At low resolution the stochastic physics scheme drastically improves both the spatial and temporal aspects of the regimes simulation. These results highlight the importance of small-scale processes on large-scale climate variability, and indicate that although simulating variability at small scales is a necessity, it may not be necessary to represent the small-scales accurately, or even explicitly, in order to improve the simulation of large-scale climate. It is argued that these results could have important implications for improving both global climate simulations, and the ability of high-resolution limited-area models, forced by low-resolution global models, to reliably simulate regional climate change signals.