TY  - JOUR
A1  - Timmer, Jens
A1  - Schwarz, Udo
A1  - Voss, Henning U.
A1  - Wardinski, Ingo
A1  - Belloni, Tomaso
A1  - Hasinger, Günther
A1  - VanDerKlis, Michael
A1  - Kurths, Jürgen
T1  - Linear and Nonlinear Time Series Analysis of the Black Hole Candidate Cygnus X-1
N2  - We analyze the variability in the x-ray lightcurves of the black hole candidate Cygnus X-1 by linear and nonlinear time series analysis methods. While a linear model describes the overall second order properties of the observed data well, surrogate data analysis reveals a significant deviation from linearity. We discuss the relation between shot noise models usually applied to analyze these data and linear stochastic autoregressive models. We debate statistical and interpretational issues of surrogate data testing for the present context. Finally, we suggest a combination of tools from linear and nonlinear time series analysis methods as a procedure to test the predictions of astrophysical models on observed data.
Y1  - 2000
UR  - http://pre.aps.org/
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
A1  - Strecker, Manfred
T1  - ENSO Impact on landslide generation in northwestern Argentina
N2  - Climatic changes are of major importance in landslide generation in the Argentine Andes. Increased humidity as a potential influential factor was inferred from the temporal clustering of landslide deposits during a period of significantly wetter climate, 30,000 years ago. A change in seasonality was tested by comparing past (inferred from annual-layered lake deposits, 30,000 years old) and modern (present-day observations) precipitation changes. Quantitative analysis of cross recurrence plots were developed to compare the influence of the El Nino/Southern Oscillation (ENSO) on present and past rainfall variations. This analysis has shown the stronger influence of NE trades in the location of landslide deposits in the intra-andean basin and valleys, what caused a higher contrast between summer and winter rainfall and an increasing of precipitation in La Nina years. This is believed to reduce thresholds for landslide generation in the arid to semiarid intra-andean basins and valleys.
Y1  - 2000
SN  - 1029-7006
ER  -