气候变化领域集成服务门户(CCPortal): Seasonality in Prediction Skill of the Madden-Julian Oscillation and Associated Dynamics in Version 2 of NASA's GEOS-S2S Forecast System

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DOI	10.1029/2021JD034961
	Seasonality in Prediction Skill of the Madden-Julian Oscillation and Associated Dynamics in Version 2 of NASA's GEOS-S2S Forecast System
	Lim Y.-K.; Arnold N.P.; Molod A.M.; Pawson S.
发表日期	2021
ISSN	2169-897X
卷号	126 期号:18
英文摘要	The prediction skill of the Madden-Julian Oscillation (MJO) in Version 2 of NASA's Global Earth Observing System Subseasonal to Seasonal (GEOS-S2S) forecast system is investigated for winter and summer focusing on moistening-related processes crucial for eastward propagating MJO activity. It is found that the annual bivariate correlation of the Real-time Multivariate MJO time series between prediction and observation is ∼0.70, ∼0.57, and ∼0.50 at 20-, 25-, and 30-day forecast leads. Correlation at long-leads (>30 days) is noticeably higher for boreal summer initial conditions (June-September [JJAS]), with correlations remaining above 0.5 at 35–40 days leads. Correlations are lower for boreal winter initial conditions from January through March (JFM), dropping to ∼0.5 at 25-day lead, still comparable to the skills in the other reliable S2S forecast systems. The predicted eastward MJO propagation across the Indo-western Pacific sector is well captured in JJAS, but is slower than observed in JFM. Investigations of the moisture field and advection and moisture sink, moist static energy (MSE) budget, and tropical circulation/pressure responses to the MJO convective heating reveal that, in JFM, those responses and moistening processes, especially the vertical MSE advection, are underestimated over and to the east of the Maritime Continent when the MJO anomaly approaches from the west. In contrast, those processes are well represented in JJAS, although moistening is overestimated due to large surface evaporation. This study suggests that improvement of the moistening tendency over that region in the boreal winter could contribute to further increases in MJO prediction skill of the GEOS-S2S system. © 2021. American Geophysical Union. All Rights Reserved. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
英文关键词	eastward MJO propagation; MJO; moistening process; S2S forecast model; subseasonal forecast
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/237005
作者单位	Goddard Earth Sciences Technology and Research / Universities Space Research Association (USRA), Columbia, MD, United States; NASA Goddard Space Flight Center, Global Modeling and Assimilation Office (GMAO), Greenbelt, MD, United States
推荐引用方式 GB/T 7714	Lim Y.-K.,Arnold N.P.,Molod A.M.,et al. Seasonality in Prediction Skill of the Madden-Julian Oscillation and Associated Dynamics in Version 2 of NASA's GEOS-S2S Forecast System[J],2021,126(18).
APA	Lim Y.-K.,Arnold N.P.,Molod A.M.,&Pawson S..(2021).Seasonality in Prediction Skill of the Madden-Julian Oscillation and Associated Dynamics in Version 2 of NASA's GEOS-S2S Forecast System.Journal of Geophysical Research: Atmospheres,126(18).
MLA	Lim Y.-K.,et al."Seasonality in Prediction Skill of the Madden-Julian Oscillation and Associated Dynamics in Version 2 of NASA's GEOS-S2S Forecast System".Journal of Geophysical Research: Atmospheres 126.18(2021).