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DOI	10.1175/JCLI-D-19-0545.1
	Does ENSO regularity increase in a warming climate?
	Berner J.; Christensen H.M.; Sardeshmukh P.D.
发表日期	2020
ISSN	0894-8755
起始页码	1247
结束页码	1259
卷号	33 期号:4
英文摘要	The impact of a warming climate on El Niño–Southern Oscillation (ENSO) is investigated in large-ensemble simulations of the Community Earth System Model (CESM1). These simulations are forced by historical emissions for the past and the RCP8.5-scenario emissions for future projections. The simulated variance of the Niño-3.4 ENSO index increases from 1.48C2 in 1921–80 to 1.98C2 in 1981–2040 and 2.28C2 in 2041–2100. The autocorrelation time scale of the index also increases, consistent with a narrowing of its spectral peak in the 3–7-yr ENSO band, raising the possibility of greater seasonal to interannual predictability in the future. Low-order linear inverse models (LIMs) fitted separately to the three 60-yr periods capture the CESM1 increase in ENSO variance and regularity. Remarkably, most of the increase can be attributed to the increase in the 23-month damping time scale of a single damped oscillatory ENSO eigenmode of these LIMs by 5 months in 1981–2040 and 6 months in 2041–2100. These apparently robust projected increases may, however, be compromised by CESM1 biases in ENSO amplitude and damping time scale. An LIM fitted to the 1921–80 observations has an ENSO eigenmode with a much shorter 8-month damping time scale, similar to that of several other eigenmodes. When the mode’s damping time scale is increased by 5 and 6 months in this observational LIM, a much smaller increase of ENSO variance is obtained than in the CESM1 projections. This may be because ENSO is not as dominated by a single ENSO eigenmode in reality as it is in the CESM1. © 2020 American Meteorological Society
英文关键词	Atmospheric pressure; Climate models; Damping; Earth (planet); Time measurement; Autocorrelation time; Earth system model; Ensemble simulation; Future projections; Historical emissions; Linear inverse models; Southern oscillation; Warming climate; Climatology; annual variation; autocorrelation; climate effect; climate modeling; computer simulation; El Nino-Southern Oscillation; ensemble forecasting; future prospect; timescale; warming; weather forecasting
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/171452
作者单位	National Center for Atmospheric Research, Boulder, CO, United States; Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, United Kingdom; Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States
推荐引用方式 GB/T 7714	Berner J.,Christensen H.M.,Sardeshmukh P.D.. Does ENSO regularity increase in a warming climate?[J],2020,33(4).
APA	Berner J.,Christensen H.M.,&Sardeshmukh P.D..(2020).Does ENSO regularity increase in a warming climate?.Journal of Climate,33(4).
MLA	Berner J.,et al."Does ENSO regularity increase in a warming climate?".Journal of Climate 33.4(2020).