气候变化领域集成服务门户(CCPortal): Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments

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DOI	10.1007/s00382-020-05607-6
	Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments
	Mayer M.; Balmaseda M.A.
发表日期	2021
ISSN	0930-7575
卷号	56 期号:2021-07-08
英文摘要	This study investigates the influence of the anomalously warm Indian Ocean state on the unprecedentedly weak Indonesian Throughflow (ITF) and the unexpected evolution of El Niño-Southern Oscillation (ENSO) during 2014–2016. It uses 25-month-long coupled twin forecast experiments with modified Indian Ocean initial conditions sampling observed decadal variations. An unperturbed experiment initialized in Feb 2014 forecasts moderately warm ENSO conditions in year 1 and year 2 and an anomalously weak ITF throughout, which acts to keep tropical Pacific ocean heat content (OHC) anomalously high. Changing only the Indian Ocean to cooler 1997 conditions substantially alters the 2-year forecast of Tropical Pacific conditions. Differences include (i) increased probability of strong El Niño in 2014 and La Niña in 2015, (ii) significantly increased ITF transports and (iii), as a consequence, stronger Pacific ocean heat divergence and thus a reduction of Pacific OHC over the two years. The Indian Ocean’s impact in year 1 is via the atmospheric bridge arising from altered Indian Ocean Dipole conditions. Effects of altered ITF and associated ocean heat divergence (oceanic tunnel) become apparent by year 2, including modified ENSO probabilities and Tropical Pacific OHC. A mirrored twin experiment starting from unperturbed 1997 conditions and several sensitivity experiments corroborate these findings. This work demonstrates the importance of the Indian Ocean’s decadal variations on ENSO and highlights the previously underappreciated role of the oceanic tunnel. Results also indicate that, given the physical links between year-to-year ENSO variations, 2-year-long forecasts can provide additional guidance for interpretation of forecasted year-1 ENSO probabilities. © 2021, The Author(s).
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183322
作者单位	Research Department, European Centre for Medium-Range Weather Forecasts, Shinfield Rd, Reading, RG2 9AX, United Kingdom; Department of Meteorology and Geophysics, University of Vienna, Vienna, Austria
推荐引用方式 GB/T 7714	Mayer M.,Balmaseda M.A.. Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments[J],2021,56(2021-07-08).
APA	Mayer M.,&Balmaseda M.A..(2021).Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments.Climate Dynamics,56(2021-07-08).
MLA	Mayer M.,et al."Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments".Climate Dynamics 56.2021-07-08(2021).