Long term memory effect in total dissolved inorganic carbon in North Pacific Ocean

Thirty years (October, 1988-December, 2018) data of North Pacific Oceanic CO2 fluctuations have been analysed using Multifractal Detrended Fluctuation Analysis technique. CO2 fluctuations obey power-law dependence on time. The multifractal spectrum of the oceanic CO2 time series has been found to be right-skewed in nature with asymmetry parameter value 0.4646. The width of the data spectrum has been calculated to be 0.62 which is higher than the corresponding shuffled series width 0.33. The dominant Hurst exponent, at which the spectrum is maximum is 0.78 for original data and 0.503 for corresponding shuffled series. Observations show that shuffled distribution does not show any correlation and hence genuine long-range correlation has been observed in CO2 which is due to time evolution and not due to the values of CO2 concentration.