TY  - GEN
A1  - Omel'chenko, Oleh
T1  - Travelling chimera states in systems of phase oscillators with asymmetric nonlocal coupling
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - We study travelling chimera states in a ring of nonlocally coupled heterogeneous (with Lorentzian distribution of natural frequencies) phase oscillators. These states are coherence-incoherence patterns moving in the lateral direction because of the broken reflection symmetry of the coupling topology. To explain the results of direct numerical simulations we consider the continuum limit of the system. In this case travelling chimera states correspond to smooth travelling wave solutions of some integro-differential equation, called the Ott–Antonsen equation, which describes the long time coarse-grained dynamics of the oscillators. Using the Lyapunov–Schmidt reduction technique we suggest a numerical approach for the continuation of these travelling waves. Moreover, we perform their linear stability analysis and show that travelling chimera states can lose their stability via fold and Hopf bifurcations. Some of the Hopf bifurcations turn out to be supercritical resulting in the observation of modulated travelling chimera states.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1169 
KW  - chimera states
KW  - nonlocally coupled phase oscillators
KW  - Ott–Antonsen equation
KW  - forced symmetry breaking
KW  - travelling waves
KW  - continuation
KW  - stability
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-518141
SN  - 1866-8372
IS  - 2
SP  - 611
EP  - 642
ER  - 
TY  - GEN
A1  - Biskaborn, Boris
A1  - Smith, Sharon L.
A1  - Noetzli, Jeannette
A1  - Matthes, Heidrun
A1  - Vieira, Gonçalo
A1  - Streletskiy, Dmitry A.
A1  - Schoeneich, Philippe
A1  - Romanovsky, Vladimir E.
A1  - Lewkowicz, Antoni G.
A1  - Abramov, Andrey
A1  - Allard, Michel
A1  - Boike, Julia
A1  - Cable, William L.
A1  - Christiansen, Hanne H.
A1  - Delaloye, Reynald
A1  - Diekmann, Bernhard
A1  - Drozdov, Dmitry
A1  - Etzelmüller, Bernd
A1  - Große, Guido
A1  - Guglielmin, Mauro
A1  - Ingeman-Nielsen, Thomas
A1  - Isaksen, Ketil
A1  - Ishikawa, Mamoru
A1  - Johansson, Margareta
A1  - Joo, Anseok
A1  - Kaverin, Dmitry
A1  - Kholodov, Alexander
A1  - Konstantinov, Pavel
A1  - Kröger, Tim
A1  - Lambiel, Christophe
A1  - Lanckman, Jean-Pierre
A1  - Luo, Dongliang
A1  - Malkova, Galina
A1  - Meiklejohn, Ian
A1  - Moskalenko, Natalia
A1  - Oliva, Marc
A1  - Phillips, Marcia
A1  - Ramos, Miguel
A1  - Sannel, A. Britta K.
A1  - Sergeev, Dmitrii
A1  - Seybold, Cathy
A1  - Skryabin, Pavel
A1  - Vasiliev, Alexander
A1  - Wu, Qingbai
A1  - Yoshikawa, Kenji
A1  - Zheleznyak, Mikhail
A1  - Lantuit, Hugues
T1  - Permafrost is warming at a global scale
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 669 
KW  - seasonal snow cover
KW  - thermal state
KW  - climate-change
KW  - activ-layer
KW  - Antarctic Peninsula
KW  - stability
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425341
SN  - 1866-8372
IS  - 669
ER  -