TITLE:
Relationship between the Atmospheric CO2 and Climate Indices by Wavelet-Based Multifractal Analysis
AUTHORS:
Fumio Maruyama
KEYWORDS:
Atmospheric CO2, δ13C, ENSO, PDO, NAO, Wavelet, Multifractal
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.1,
January
22,
2019
ABSTRACT: Atmospheric concentrations of greenhouse gases are rising, leading to a positive
radiative forcing of climate and an expected warming of surface temperatures.
In general, fractal properties may be observed in the time series of the
dynamics of complex systems. To study the relation between the atmospheric
CO2 concentration and the climate indices, we investigated the change of
fractal behavior of the CO2, the carbon isotope ratio (δ13C) of atmospheric
CO2, the El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation
(PDO), and the North Atlantic Oscillation (NAO) indices using the multifractal
analysis. When the atmospheric CO2 growth rate was large, the multifractality
of CO2, δ13C in CO2, ENSO, and NAO was large and the changes
were large from the change of fractality. The changes of CO2 and ENSO were
closely related and the influence of the CO2 on the ENSO was strong from the
change in fractality and wavelet coherence. When the El Niño occurred, the
CO2 growth rate was large. The CO2 related to PDO, NAO, and global temperature
from the change in fractality and wavelet coherence. Especially, the
changes of CO2 and global temperature were closely related. When the global
warming hiatus occurred, the multifractality of the global temperature was
weaker than that of CO2 and the change of the global temperature was stable.
These findings will contribute to the research of the relation between the atmospheric
CO2 and climate change.