Investigation of power-law correlations within daily total ozone time series and search for a stable node through phase portrait

In the study reported in this paper we have dealt with the intrinsic complexity of the daily total ozone time series over Mumbai, India (19 degrees 23'N, 72 15 degrees 00'E) by means of detrended fluctuation analysis and phase portrait analysis. From the detrended fluctuation analysis of first order it is revealed that the said time series is characterized by persistent power-law correlation which is stronger in shorter time scale than in the longer time scale. The phase portrait analysis is based on a non-linear autonomous system generated from regression equations; infinitely many stable nodes are found along the straight line x = 273.556 and from the behaviors of the contours, it has been revealed that the daily total ozone concentration is unlikely to go beyond 315 DU (approximately) and it is almost stable. (C) 2013 Published by Elsevier Masson SAS on behalf of Academie des sciences.