Winter NH low-frequency variability in a hierarchy of low-order stochastic dynamical models of earth-atmosphere system
Winter NH low-frequency variability in a hierarchy of low-order stochastic dynamical models of earth-atmosphere system
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地球-大气系统低阶随机动力学模型层次中的冬季 NH 低频变化
DOI：
10.1007/s00704-016-2021-5
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发表时间：
2018-02
影响因子：
3.4
通讯作者：
赵南
中科院分区：
文献类型：
--
作者：
赵南
冬季北方半球低频变率（LFV）的成因被认为与以急流与中纬度山脉相互作用为特征的地气耦合系统有关。另一方面，观测到的LFV通常出现在北方半球的多个行星尺度流态之间，如NAO +，AO +，AO-和NAO-。此外，天气尺度涡旋与行星尺度扰动的相互作用也是LFV形成的必然原因。这就提出了一个问题，即如何将所有这些方面纳入一个框架，以证明（1）急流与中纬度山脉相互作用的行星尺度动力学可以真正产生LFV，（2）这种动力学可以负责上述多种流态的存在，以及（3）与涡的相互作用的作用也得到了澄清。为此，低阶随机动力学模型的层次结构的耦合地气系统的经验来自不同的时间尺度范围内的指标北极涛动（AO），北大西洋涛动（NAO），太平洋/北美（PNA），和日长（LOD）和相关的概率密度函数（PDF）分析在这项研究中。这些结果似乎表明，LFV的起源不能完全在急流与中纬度山脉相互作用的行星尺度动力学中理解，因为（1）NAO+，AO+，AO-和NAO-等多种流型的存在是由时间尺度比LFV本身长得多的过程造成的，这可能具有地形-急流相互作用以外的潜在动力学，（2）虽然LFV也能产生类似的振荡行为，但LFV不一定直接来自于急流与中纬度山脉相互作用的行星尺度动力学。天气尺度涡旋对行星尺度动力学的反馈/强迫似乎在其起源中起着更重要的作用。
The origin of winter Northern Hemispheric low-frequency variability (hereafter, LFV) is regarded to be related to the coupled earth-atmosphere system characterized by the interaction of the jet stream with mid-latitude mountain ranges. On the other hand, observed LFV usually appears as transitions among multiple planetary-scale flow regimes of Northern Hemisphere like NAO + , AO +, AO − and NAO − . Moreover, the interaction between synoptic-scale eddies and the planetary-scale disturbance is also inevitable in the origin of LFV. These raise a question regarding how to incorporate all these aspects into just one framework to demonstrate (1) a planetary-scale dynamics of interaction of the jet stream with mid-latitude mountain ranges can really produce LFV, (2) such a dynamics can be responsible for the existence of above multiple flow regimes, and (3) the role of interaction with eddy is also clarified. For this purpose, a hierarchy of low-order stochastic dynamical models of the coupled earth-atmosphere system derived empirically from different timescale ranges of indices of Arctic Oscillation (AO), North Atlantic Oscillation (NAO), Pacific/North American (PNA), and length of day (LOD) and related probability density function (PDF) analysis are employed in this study. The results seem to suggest that the origin of LFV cannot be understood completely within the planetary-scale dynamics of the interaction of the jet stream with mid-latitude mountain ranges, because (1) the existence of multiple flow regimes such as NAO+, AO+, AO− and NAO− resulted from processes with timescales much longer than LFV itself, which may have underlying dynamics other than topography-jet stream interaction, and (2) we find LFV seems not necessarily to come directly from the planetary-scale dynamics of the interaction of the jet stream with mid-latitude mountain, although it can produce similar oscillatory behavior. The feedback/forcing of synoptic-scale eddies on the planetary-scale dynamics seems to play a more essential role in its origin.
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影响因子：
3.1
作者：
J. Berner;G. Branstator
通讯作者：
J. Berner;G. Branstator
影响因子：
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作者：
J. Dickey;M. Ghil;S. Marcus
通讯作者：
J. Dickey;M. Ghil;S. Marcus
DOI：
10.1111/j.1600-0870.2006.00204.x
发表时间：
2006-01
期刊：
Tellus A: Dynamic Meteorology and Oceanography
影响因子：
--
作者：
N. Zhao;M. Takahashi
通讯作者：
N. Zhao;M. Takahashi
DOI：
10.1073/pnas.0900173106
发表时间：
2009-03
期刊：
Proceedings of the National Academy of Sciences
影响因子：
--
作者：
A. Majda;C. Franzke;D. Crommelin
通讯作者：
A. Majda;C. Franzke;D. Crommelin
DOI：
10.1016/s0167-2789(02)00578-x
发表时间：
2002-09
期刊：
Physica D: Nonlinear Phenomena
影响因子：
--
作者：
A. Majda;I. Timofeyev;E. Vanden-Eijnden
通讯作者：
A. Majda;I. Timofeyev;E. Vanden-Eijnden