Causal Relationships between Climate Indices and the Solar Constant over the Last 100 Years

Causal relationships between the North Atlantic Oscillation (NAO), El Nino-Southern Oscillation (ENSO, NINO 3.4), Pacific Decadal Oscillation (PDO), and Total Solar Irradiance (TSI) climate indices over the past 120 years have been analyzed using the method of conditional dispersion (Cenys et al., 1991). First, the method was calibrated using the Ocean-Atmosphere conceptual model by adding TSI as an external forcing. The method was shown to be adequate and capable of assessing the effect of one time series to another even if the data contain noise. As a result, TSI was found to affect NINO 3.4 and PDO, but the direction of the relationship for NAO and TSI was not revealed.