1/f noise and multifractality in atmospheric-CO2 records

We study the fluctuations in the measured atmospheric CO2 records from several stations and show that it displays 1/f noise and multifractality. Using detrended fluctuation analysis and wavelet based methods, we estimate thescaling exponents at various time scales. We also simulate CO2 time series from an atmospheric chemistry-transport model (CTM) and show that eventhough the model results are in broad agreement with the measured exponents there are still some discrepancies between them. The implications for sources and sinks inversion of atmospheric-CO2 is discussed.