气候变化领域集成服务门户(CCPortal): The value of initialization on decadal timescales: State-dependent predictability in the CESM decadal prediction large ensemble

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DOI	10.1175/JCLI-D-19-0571.1
	The value of initialization on decadal timescales: State-dependent predictability in the CESM decadal prediction large ensemble
	Christensen H.M.; Berner J.; Yeager S.
发表日期	2020
ISSN	0894-8755
起始页码	7353
结束页码	7370
卷号	33 期号:17
英文摘要	Information in decadal climate prediction arises from a well-initialized ocean state and from the predicted response to an external forcing. The length of time over which the initial conditions benefit the decadal forecast depends on the start date of the forecast. We characterize this state-dependent predictability for decadal forecasts of upper ocean heat content in the Community Earth System Model. We find regionally dependent initial condition predictability, with extended predictability generally observed in the extratropics. We also detect state-dependent predictability, with the year of loss of information from the initialization varying between start dates. The decadal forecasts in the North Atlantic show substantial information from the initial conditions beyond the 10-yr forecast window, and a high degree of state-dependent predictability. We find some evidence for state-dependent predictability in the ensemble spread in this region, similar to that seen in weather and subseasonal-to-seasonal forecasts. For some start dates, an increase of information with lead time is observed, for which the initialized forecasts predict a growing phase of the Atlantic multidecadal oscillation. Finally we consider the information in the forecast from the initial conditions relative to the forced response, and quantify the crossover time scale after which the forcing provides more information. We demonstrate that the climate change signal projects onto different patterns than the signal from the initial conditions. This means that even after the crossover time scale has been reached in a basin-averaged sense, the benefits of initialization can be felt locally on longer time scales. © 2020 American Meteorological Society.
英文关键词	Climate change; Time measurement; Atlantic multidecadal oscillations; Climate prediction; Decadal predictions; Earth system model; External forcing; Forced response; Initial conditions; Seasonal forecasts; Forecasting; climate modeling; climate prediction; decadal variation; ensemble forecasting; sea state; sea surface temperature; timescale; Atlantic Ocean; Atlantic Ocean (North)
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171156
作者单位	Atmospheric Oceanic and Planetary Physics, University of Oxford, Oxford, United Kingdom; National Center for Atmospheric Research, Boulder, CO, United States
推荐引用方式 GB/T 7714	Christensen H.M.,Berner J.,Yeager S.. The value of initialization on decadal timescales: State-dependent predictability in the CESM decadal prediction large ensemble[J],2020,33(17).
APA	Christensen H.M.,Berner J.,&Yeager S..(2020).The value of initialization on decadal timescales: State-dependent predictability in the CESM decadal prediction large ensemble.Journal of Climate,33(17).
MLA	Christensen H.M.,et al."The value of initialization on decadal timescales: State-dependent predictability in the CESM decadal prediction large ensemble".Journal of Climate 33.17(2020).