Indications for a North Atlantic ocean circulation regime shift at the onset of the Little Ice Age

Schleußner, Carl-Friedrich; Divine, D.; Donges, Jonathan F.; Miettinen, Arto; Donner, Reik V.

doi:10.1007/s00382-015-2561-x

Cited by 29 publications

(34 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The latter resulted, on the one hand, in a baroclinic spin-up of the SPG due to increasing recirculation of subtropical water into the subpolar region and, on the other hand, in a LIA-like basin-wide cooling due to weakened heat transport by the AMOC. These results agree with SST reconstructions from the Nordic Seas and the eastern subpolar North Atlantic (Schleussner et al 2015; these SST reconstructions are also shown in Fig. 7c, d), although their simulated SPG spin-up differs from reconstructed evidence of a weaker SPG during the LIA (e.g., Copard et al 2012;Moffa-Sánchez et al 2014a), which is more in accordance with our study.…”

Section: The Medieval Climate Anomaly: Little Ice Age Transitionsupporting

confidence: 82%

“…These results contrast with previous studies in which similar abrupt events were attributed to the volcanic forcing alone in climate simulations of the past millennium (Miller et al 2012;Schleussner and Feulner 2013;Schleussner et al 2015). The sensitivity experiments used here, however, still include changes in the other imposed external forcings (see Sect.…”

Section: Attribution Of the Spg Changes In The Last Millenniumcontrasting

confidence: 55%

“…Our dynamical interpretation of the transition toward LIA-type episodes differs from previously suggested mechanisms for other similar abrupt climate transitions in the North Atlantic (Miller et al 2012;Drijfhout et al 2013;Lehner et al 2013;Schleussner and Feulner 2013;Schleussner et al 2015). These modeling studies primarily related the cold climate conditions in the North Atlantic to a slowdown of the meridional heat transport by the AMOC, in agreement with records describing a weak AMOC during the LIA (Lund et al 2006;Wanamaker et al 2012).…”

Section: The Medieval Climate Anomaly: Little Ice Age Transitioncontrasting

confidence: 46%

See 2 more Smart Citations

An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

et al. 2016

View full text Add to dashboard Cite

show abstract

Section: The Medieval Climate Anomaly: Little Ice Age Transitionsupporting

confidence: 82%

Section: Attribution Of the Spg Changes In The Last Millenniumcontrasting

confidence: 55%

Section: The Medieval Climate Anomaly: Little Ice Age Transitioncontrasting

confidence: 46%

See 1 more Smart Citation

An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

et al. 2016

View full text Add to dashboard Cite

show abstract

“…In particular, Seidenkrantz et al (2007) report an oceanic warming south of Greenland for Greenland. From independent proxy data it is known that during that time, the sea ice extent could be lower than average 500 which, again, could be a signature of the ocean circulation response triggered by negative anomalies in the radiative forcing (Schleussner et al, 2015;Otterå et al, 2010).…”

mentioning

confidence: 99%

Spatio-temporal variability of Arctic summer temperatures over the past two millennia: an overview of the last major climate anomalies

Werner

Divine

Ljungqvist

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract.In this article, the first spatially resolved millennium-long summer (June-August) temperature reconstruction over the Arctic and Subarctic domain (north of 60• N) is presented. It is based on a set of 54 annually dated temperature sensitive proxy archives of various types, mainly from the updated and revised PAGES2k database supplemented with 6 new recently published proxy records. As a major novelty, an extension of the Bayesian BARCAST climate field (CF) reconstruction technique provides 5 a means to treat climate archives with dating uncertainties. In total 1400 realisations of the temperature CF were generated, enabling further analyses to be carried out in a probabilistic framework. The new seasonal CF reconstruction for the Arctic region can be shown to be skilful for the majority of the terrestrial nodes. The decrease in the proxy data density back in time however limits the analyses in the spatial domain to the period after 750 CE, while the spatially averaged reconstruction covers the entire time interval of 1-2002 CE. The analysis of basic features of the reconstructed seasonal CF focuses on the regional 10 expression of past major climate anomalies in order to uncover the potential of the new product for studying Common Era temperature variability in the region.The long-term, centennial to millennial, evolution of the reconstructed temperature is in good agreement with a general pattern that was inferred in recent studies for the Arctic and its sub-regions. On the pan-Arctic scale the reconstruction shows a cooling trend which is, however, statistically insignificant and the estimated magnitude of the millennial scale cooling is three

show abstract

“…30 It is instructive to also apply this methodology to study regime shifts in paleoclimate dynamics, 154 particularly for investigating in depth the important differences between interglacial and glacial climate variability and the nature of the transitions between those regimes. 91 As an example, we study the 2 m resolution d 18 O isotope record from the GISP2 ice core from Greenland 153 covering both the Holocene and the last glacial period (Fig.…”

Section: Use Case: Time Irreversibility In Glacial-deglacial Dynamicsmentioning

confidence: 99%

Unified functional network and nonlinear time series analysis for complex systems science: The`pyunicorn`package

Donges

Heitzig

Beronov

et al. 2015

Chaos

111

View full text Add to dashboard Cite

We introduce the pyunicorn (Pythonic unified complex network and recurrence analysis toolbox) open source software package for applying and combining modern methods of data analysis and modeling from complex network theory and nonlinear time series analysis. pyunicorn is a fully object-oriented and easily parallelizable package written in the language Python. It allows for the construction of functional networks such as climate networks in climatology or functional brain networks in neuroscience representing the structure of statistical interrelationships in large data sets of time series and, subsequently, investigating this structure using advanced methods of complex network theory such as measures and models for spatial networks, networks of interacting networks, node-weighted statistics or network surrogates. Additionally, pyunicorn provides insights into the nonlinear dynamics of complex systems as recorded in uni-and multivariate time series from a non-traditional perspective by means of recurrence quantification analysis (RQA), recurrence networks, visibility graphs and construction of surrogate time series. The range of possible applications of the library is outlined, drawing on several examples mainly from the field of climatology.Network theory and nonlinear time series analysis provide powerful tools for the study of complex systems in various disciplines such as climatology, neuroscience, social science, infrastructure or economics. In the last years, combining both frameworks has yielded a wealth of new approaches for understanding and modeling the structure and dynamics of such systems based on the statistical analysis of network or uni-and multivariate time series. The pyunicorn software package (available at https://github.com/pik-copan/pyunicorn) facilitates the innovative synthesis of methods from network theory and nonlinear time series analysis in order to develop novel integrated methodologies. This paper provides an overview of the functionality provided by pyunicorn, introduces the theoretical concepts behind it and provides examples in the form of selected use cases mainly in the fields of climatology and paleoclimatology.

show abstract

Indications for a North Atlantic ocean circulation regime shift at the onset of the Little Ice Age

Cited by 29 publications

References 70 publications

An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

Spatio-temporal variability of Arctic summer temperatures over the past two millennia: an overview of the last major climate anomalies

Unified functional network and nonlinear time series analysis for complex systems science: The`pyunicorn`package

Contact Info

Product

Resources

About

Indications for a North Atlantic ocean circulation regime shift at the onset of the Little Ice Age

Cited by 29 publications

References 70 publications

An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

Spatio-temporal variability of Arctic summer temperatures over the past two millennia: an overview of the last major climate anomalies

Unified functional network and nonlinear time series analysis for complex systems science: Thepyunicornpackage

Contact Info

Product

Resources

About

Unified functional network and nonlinear time series analysis for complex systems science: The`pyunicorn`package