Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1007/s00382-019-05018-2 |
A new mathematical framework for atmospheric blocking events | |
Lucarini, Valerio1,2,3; Gritsun, Andrey4 | |
2019-11-01 | |
发表期刊 | CLIMATE DYNAMICS |
ISSN | 0930-7575 |
EISSN | 1432-0894 |
出版年 | 2019 |
文章类型 | Article;Early Access |
语种 | 英语 |
国家 | England; Germany; Russia |
英文摘要 | We use a simple yet Earth-like hemispheric atmospheric model to propose a new framework for the mathematical properties of blocking events. Using finite-time Lyapunov exponents, we show that the occurrence of blockings is associated with conditions featuring anomalously high instability. Longer-lived blockings are very rare and have typically higher instability. In the case of Atlantic blockings, predictability is especially reduced at the onset and decay of the blocking event, while a relative increase of predictability is found in the mature phase. The opposite holds for Pacific blockings, for which predictability is lowest in the mature phase. Blockings are realised when the trajectory of the system is in the neighbourhood of a specific class of unstable periodic orbits (UPOs), natural modes of variability that cover the attractor the system. UPOs corresponding to blockings have, indeed, a higher degree of instability compared to UPOs associated with zonal flow. Our results provide a rigorous justification for the classical Markov chains-based analysis of transitions between weather regimes. The analysis of UPOs elucidates that the model features a very severe violation of hyperbolicity, due to the presence of a substantial variability in the number of unstable dimensions, which explains why atmospheric states can differ a lot in term of their predictability. Additionally, such a variability explains the need for performing data assimilation in a state space that includes not only the unstable and neutral subspaces, but also some stable modes. The lack of robustness associated with the violation of hyperbolicity might be a basic cause contributing to the difficulty in representing blockings in numerical models and in predicting how their statistics will change as a result of climate change. This corresponds to fundamental issues limiting our ability to construct very accurate numerical models of the atmosphere, in term of predictability of the both the first and of the second kind in the sense of Lorenz. |
英文关键词 | Atmospheric blockings Unstable periodic orbits Covariant Lyapunov vectors Lyapunov exponents Predictability Numerical modelling |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000493640000001 |
WOS关键词 | UNSTABLE PERIODIC-ORBITS ; LOW-FREQUENCY VARIABILITY ; WEATHER REGIME TRANSITIONS ; NORTHERN-HEMISPHERE WINTER ; MULTIPLE FLOW REGIMES ; STATISTICAL PROPERTIES ; LYAPUNOV VECTORS ; ATLANTIC BLOCKING ; NATURAL MEASURE ; ERROR GROWTH |
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/187968 |
专题 | 气候变化 |
作者单位 | 1.Univ Reading, Dept Math & Stat, Reading, Berks, England; 2.Univ Reading, Ctr Math Planet Earth, Reading, Berks, England; 3.Univ Hamburg, CEN, Hamburg, Germany; 4.Russian Acad Sci, Inst Numer Math, Moscow, Russia |
推荐引用方式 GB/T 7714 | Lucarini, Valerio,Gritsun, Andrey. A new mathematical framework for atmospheric blocking events[J]. CLIMATE DYNAMICS,2019. |
APA | Lucarini, Valerio,&Gritsun, Andrey.(2019).A new mathematical framework for atmospheric blocking events.CLIMATE DYNAMICS. |
MLA | Lucarini, Valerio,et al."A new mathematical framework for atmospheric blocking events".CLIMATE DYNAMICS (2019). |
条目包含的文件 | 条目无相关文件。 |
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