Is interannual fluctuation of atmospheric CO2 dominated by combined effects of ENSO and volcanic aerosols

摘要: [1] The influence of ENSO, volcanic eruptions, and the North Atlantic Oscillation (NAO) on fluctuations atmospheric CO2 concentration were globally investigated ENSO timescale for period 1958 to 1994. Two deseasonalized detrended monthly time series anomalous fluxes generated: (1) modeled terrestrial biospheric flux anomalies calculated by High Resolution Biosphere Model (HRBM) driven realistic temperature precipitation data but without considering radiation effects (2) deduced from measurements. While comparing two series, three types periods could be distinguished: “a” with a phase shift close zero between “b” up 11 months, “c” curves completely out phase. During show carbon release biosphere while observed uptake. The type are accompanied major eruptions considerable aerosol production. Enhanced loading can increase diffuse fraction solar radiation. Diffuse in many cases penetrates better into plant canopies thus potentially enhancing photosynthesis. resulting additional uptake may have overcompensated caused possibly bringing about net CO2. length variations lags (“b” periods) attributed impacts vegetation fires. NAO remained unclear.