气候变化领域集成服务门户(CCPortal): The Southern Hemisphere Minor Sudden Stratospheric Warming in September 2019 and its Predictions in S2S Models

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DOI	10.1029/2020JD032723
	The Southern Hemisphere Minor Sudden Stratospheric Warming in September 2019 and its Predictions in S2S Models
	Rao J.; Garfinkel C.I.; White I.P.; Schwartz C.
发表日期	2020
ISSN	2169897X
卷号	125 期号:14
英文摘要	A minor sudden stratospheric warming (SSW) happened in September 2019 in the Southern Hemisphere (SH) with winds at 10 hPa, 60°S reaching their minimum value on 18 September. Using multiple data sets and real-time predictions from 11 subseasonal to seasonal (S2S) models, the evolution, favorable conditions, and predictability for this SSW event are explored. The September 2019 SSW happened during several favorable conditions, including easterly equatorial quasi-biennial oscillation (QBO) winds at 10 hPa, solar minimum, positive Indian Ocean Dipole (IOD) sea surface temperatures (SST), warm SST anomalies in the central Pacific, and a blocking high near the Antarctic Peninsula. With these favorable initial and boundary conditions, the predictive limit to this SSW is around 18 days in some S2S models, and more than 50% of the ensemble members forecast the zonal wind deceleration in reforecasts initialized around 29 August. A vortex slowdown is evident in some initializations from around 22 August, but with a forecast-reanalysis pattern correlation %3C0.5, while initializations later than 29 August capture the wavelike pattern in the troposphere and the subsequent stratospheric evolution. The ensemble spread in the magnitude of the vortex deceleration during the SSW is mainly explained by the ensemble spread in the magnitude of upward propagation of waves in the troposphere and in the stratosphere, with an underestimated tropospheric wave amplitude leading to a too-small deceleration of the vortex. The September 2019 SH SSW did not show a near-instantaneous downward impact on the tropospheric southern annular mode (SAM) in late September and early October 2019. The Australian drought and hot weather in September possibly associated with the positive IOD might have been exacerbated by the negative SAM in October and later months due to the weak stratospheric polar vortex. However, models tend to forecast a near-instantaneous tropospheric response to the SSW. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	predictability; September 2019; Southern Hemisphere (SH); subseasonal to seasonal (S2S); sudden stratospheric warming (SSW)
语种	英语
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/185896
作者单位	Fredy and Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel; Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing, China
推荐引用方式 GB/T 7714	Rao J.,Garfinkel C.I.,White I.P.,et al. The Southern Hemisphere Minor Sudden Stratospheric Warming in September 2019 and its Predictions in S2S Models[J],2020,125(14).
APA	Rao J.,Garfinkel C.I.,White I.P.,&Schwartz C..(2020).The Southern Hemisphere Minor Sudden Stratospheric Warming in September 2019 and its Predictions in S2S Models.Journal of Geophysical Research: Atmospheres,125(14).
MLA	Rao J.,et al."The Southern Hemisphere Minor Sudden Stratospheric Warming in September 2019 and its Predictions in S2S Models".Journal of Geophysical Research: Atmospheres 125.14(2020).