DOI: 10.1007/s00382-014-2161-1
Scopus记录号: 2-s2.0-84939893424
论文题名: Strategies for reducing the climate noise in model simulations: ensemble runs versus a long continuous run
作者: Decremer D. ; Chung C.E. ; Räisänen P.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 44, 期: 2017-05-06 起始页码: 1367
结束页码: 1379
语种: 英语
英文关键词: Autocorrelation
; Climate noise
; Coupled model
; Ensemble simulation
; Internal variability
; Persistence
英文摘要: Climate modelers often integrate the model with constant forcing over a long time period, and make an average over the period in order to reduce climate noise. If the time series is persistent, as opposed to rapidly varying, such an average does not reduce noise efficiently. In this case, ensemble runs, which ideally represent independent runs, can reduce noise more efficiently. We quantify the noise reduction gain by using ensemble runs over a long continuous run in constant‐forcing simulations. We find that in terms of the amplitude of the noise, a continuous simulation of 30 years may be equivalent to as few as five 3-year long ensemble runs in a slab ocean–atmosphere coupled model and as few as two 3-year long ensemble runs in a fully coupled model. The outperformance of ensemble runs over a continuous run is strictly a function of the persistence of the time series. We find that persistence depends on model, location and variable, and that persistence in surface air temperature has robust spatial structures in coupled models. We demonstrate that lag-1 year autocorrelation represents persistence fairly well, but the use of lag-1 year–lag-5 years autocorrelations represents the persistence far more sufficiently. Furthermore, there is more persistence in coupled model output than in the output of a first-order autoregressive model with the same lag-1 autocorrelation. © 2014, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54230
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea; Finnish Meteorological Institute, Helsinki, Finland
Recommended Citation:
Decremer D.,Chung C.E.,Räisänen P.. Strategies for reducing the climate noise in model simulations: ensemble runs versus a long continuous run[J]. Climate Dynamics,2015-01-01,44(2017-05-06)