Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1175/JAS-D-19-0249.1 |
Why Are Stratospheric Sudden Warmings Sudden (and Intermittent)? | |
Nakamura, Noboru1; Falk, Jonathan1; Lubis, Sandro W.2 | |
2020-03-01 | |
发表期刊 | JOURNAL OF THE ATMOSPHERIC SCIENCES |
ISSN | 0022-4928 |
EISSN | 1520-0469 |
出版年 | 2020 |
卷号 | 77期号:3页码:943-964 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | This paper examines the role of wave-mean flow interaction in the onset and suddenness of stratospheric sudden warmings (SSWs). Evidence is presented that SSWs are, on average, a threshold behavior of finite-amplitude Rossby waves arising from the competition between an increasing wave activity A and a decreasing zonal-mean zonal wind u over bar . The competition puts a limit to the wave activity flux that a stationary Rossby wave can transmit upward. A rapid, spontaneous vortex breakdown occurs once the upwelling wave activity flux reaches the limit, or equivalently, once u over bar drops below a certain fraction of u(REF), a wave-free, reference-state wind inverted from the zonalized quasigeostrophic potential vorticity. This fraction is 0.5 in theory and about 0.3 in reanalyses. We propose r equivalent to u over bar /uREF as a local, instantaneous measure of the proximity to vortex breakdown (i.e., preconditioning). The ratio r generally stays above the threshold during strong-vortex winters until a pronounced final warming, whereas during weak-vortex winters it approaches the threshold early in the season, culminating in a precipitous drop in midwinter as SSWs form. The essence of the threshold behavior is captured by a semiempirical 1D model of SSWs, similar to the "traffic jam" model of Nakamura and Huang for atmospheric blocking. This model predicts salient features of SSWs including rapid vortex breakdown and downward migration of the wave activity/zonal wind anomalies, with analytical expressions for the respective time scales. The model's response to a variety of transient wave forcing and damping is discussed. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000515507400002 |
WOS关键词 | AMPLITUDE WAVE ACTIVITY ; PLANETARY-WAVES ; NUMERICAL-MODEL ; POLAR VORTEX ; PART I ; POTENTIAL VORTICITY ; ROSSBY WAVES ; LIFE-CYCLE ; FLOW ; EVENTS |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/280307 |
专题 | 地球科学 |
作者单位 | 1.Univ Chicago, Dept Geophys Sci, 5734 S Ellis Ave, Chicago, IL 60637 USA; 2.Rice Univ, Dept Mech Engn, Houston, TX 77005 USA |
推荐引用方式 GB/T 7714 | Nakamura, Noboru,Falk, Jonathan,Lubis, Sandro W.. Why Are Stratospheric Sudden Warmings Sudden (and Intermittent)?[J]. JOURNAL OF THE ATMOSPHERIC SCIENCES,2020,77(3):943-964. |
APA | Nakamura, Noboru,Falk, Jonathan,&Lubis, Sandro W..(2020).Why Are Stratospheric Sudden Warmings Sudden (and Intermittent)?.JOURNAL OF THE ATMOSPHERIC SCIENCES,77(3),943-964. |
MLA | Nakamura, Noboru,et al."Why Are Stratospheric Sudden Warmings Sudden (and Intermittent)?".JOURNAL OF THE ATMOSPHERIC SCIENCES 77.3(2020):943-964. |
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