TY  - JOUR
A1  - Malik, Nishant
A1  - Zou, Y.
A1  - Marwan, Norbert
A1  - Kurths, Jürgen
T1  - Dynamical regimes and transitions in plio-pleistocene Asian monsoon
JF  - epl : a letters journal exploring the frontiers of physics
N2  - We propose a novel approach based on the fluctuation of similarity to identify regimes of distinct dynamical complexity in short time series. A statistical test is developed to estimate the significance of the identified transitions. Our method is verified by uncovering bifurcation structures in several paradigmatic models, providing more complex transitions compared with traditional Lyapunov exponents. In a real-world situation, we apply this method to identify millennial-scale dynamical transitions in Plio-Pleistocene proxy records of the South Asian summer monsoon system. We infer that many of these transitions are induced by the external forcing of the solar insolation and are also affected by internal forcing on Monsoonal dynamics, i.e., the glaciation cycles of the Northern Hemisphere and the onset of the Walker circulation.
Y1  - 2012
U6  - https://doi.org/10.1209/0295-5075/97/40009
SN  - 0295-5075
VL  - 97
IS  - 4
PB  - EDP Sciences
CY  - Mulhouse
ER  - 
TY  - JOUR
A1  - Malik, Nishant
A1  - Bookhagen, Bodo
A1  - Marwan, Norbert
A1  - Kurths, Jürgen
T1  - Analysis of spatial and temporal extreme monsoonal rainfall over South Asia using complex networks
JF  - Climate dynamics : observational, theoretical and computational research on the climate system
N2  - We present a detailed analysis of summer monsoon rainfall over the Indian peninsular using nonlinear spatial correlations. This analysis is carried out employing the tools of complex networks and a measure of nonlinear correlation for point processes such as rainfall, called event synchronization. This study provides valuable insights into the spatial organization, scales, and structure of the 90th and 94th percentile rainfall events during the Indian summer monsoon (June-September). We furthermore analyse the influence of different critical synoptic atmospheric systems and the impact of the steep Himalayan topography on rainfall patterns. The presented method not only helps us in visualising the structure of the extreme-event rainfall fields, but also identifies the water vapor pathways and decadal-scale moisture sinks over the region. Furthermore a simple scheme based on complex networks is presented to decipher the spatial intricacies and temporal evolution of monsoonal rainfall patterns over the last 6 decades.
KW  - Indian summer monsoon
KW  - Event synchronization
KW  - Complex networks
KW  - Rainfall patterns
Y1  - 2012
U6  - https://doi.org/10.1007/s00382-011-1156-4
SN  - 0930-7575
VL  - 39
IS  - 3-4
SP  - 971
EP  - 987
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Beller, Gise
A1  - Felsenberg, Dieter
A1  - Saparin, Peter
A1  - Kurths, Jürgen
T1  - quantifying changes in the spatial structure of trabecular bone
JF  - International journal of bifurcation and chaos : in applied sciences and engineering
N2  - We apply recently introduced measures of complexity for the structural quantification of distal tibial bone. For the first time, we are able to investigate the temporal structural alteration of trabecular bone. Based on four patients, we show how the bone may alter due to temporal immobilization.
KW  - 3D medical image analysis
KW  - pQCT
KW  - trabecular bone
KW  - patient immobilization
Y1  - 2012
U6  - https://doi.org/10.1142/S0218127412500277
SN  - 0218-1274
VL  - 22
IS  - 2
PB  - World Scientific
CY  - Singapore
ER  -