气候变化领域集成服务门户(CCPortal): The Boreal Winter El Ninõ Precipitation Response over North America: Insights into Why January Is More Difficult to Predict Than February

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DOI	10.1175/JCLI-D-19-0841.1
	The Boreal Winter El Ninõ Precipitation Response over North America: Insights into Why January Is More Difficult to Predict Than February
	Lim Y.-K.; Schubert S.D.; Chang Y.; Wang H.
发表日期	2020
ISSN	0894-8755
起始页码	8651
结束页码	8670
卷号	33 期号:20
英文摘要	This study examines the within-season monthly variation of the El Ninõ response over North America during December-March using the NASA/GEOS model. In agreement with previous studies, the skill of 1-month-lead GEOS coupled model forecasts of precipitation over North America is largest (smallest) for February (January), with similar results in uncoupled mode. A key finding is that the relatively poor January skill is the result of the model placing the main circulation anomaly over the northeast Pacific slightly to the west of the observed, resulting in precipitation anomalies that lie off the coast instead of over land as observed. In contrast, during February the observed circulation anomaly over the northeast Pacific shifts westward, lining up with the predicted anomaly, which is essentially unchanged from January, resulting in both the observed and predicted precipitation anomalies remaining off the coast. Furthermore, the largest precipitation anomalies occur along the southern tier of states associated with an eastward extended jet-something that the models capture reasonably well. Simulations with a stationary wave model indicate that the placement of January El Ninõ response to the west of the observed over the northeast Pacific is the result of biases in the January climatological stationary waves, rather than errors in the tropical Pacific El Ninõ heating anomalies in January. Furthermore, evidence is provided that the relatively poor simulation of the observed January climatology, characterized by a strengthened North Pacific jet and enhanced ridge over western North America, can be traced back to biases in the January climatology heating over the Tibet region and the tropical western Pacific. ©2020 American Meteorological Society.
英文关键词	Climatology; NASA; Boreal winters; Circulation anomalies; Coupled modeling; Precipitation anomalies; Stationary wave model; Stationary waves; Tropical Western Pacific; Uncoupled modes; Tropics; climate modeling; climate variation; El Nino; precipitation assessment; prediction; seasonal variation; weather forecasting; Pacific Ocean; Pacific Ocean (Northeast); Pacific Ocean (West)
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/171142
作者单位	Nasa Goddard Space Flight Center, Global Modeling and Assimilation Office, Greenbelt, MD, United States; Goddard Earth Sciences Technology and Research/Universities Space Research Association, Columbia, MD, United States; Science Systems and Applications, Inc., Lanham, MD, United States; Goddard Earth Sciences Technology and Research/Morgan State University, Baltimore, MD, United States; Noaa Climate Prediction Center, College Park, MD, United States
推荐引用方式 GB/T 7714	Lim Y.-K.,Schubert S.D.,Chang Y.,et al. The Boreal Winter El Ninõ Precipitation Response over North America: Insights into Why January Is More Difficult to Predict Than February[J],2020,33(20).
APA	Lim Y.-K.,Schubert S.D.,Chang Y.,&Wang H..(2020).The Boreal Winter El Ninõ Precipitation Response over North America: Insights into Why January Is More Difficult to Predict Than February.Journal of Climate,33(20).
MLA	Lim Y.-K.,et al."The Boreal Winter El Ninõ Precipitation Response over North America: Insights into Why January Is More Difficult to Predict Than February".Journal of Climate 33.20(2020).