Effects of the Pacific Decadal Oscillation on the Characteristics of Two Types of El Nio under Possible Climate Change

D. Yu. Gushchina, M. V. Kalinovskaya and T. A. Matveeva

The effect of the Pacific Decadal Oscillation (PDO) phase on the intensity and localization of anomalies in sea surface temperature and meteorological parameters associated with two types of El Nio is analyzed. The analysis is based on reanalysis and CMIP5 model data for modern and future climate (RCP8.5 scenario). It is found that El Nio does not exhibit robust intensification during the positive PDO phase, as mentioned in the previous studies, but the PDO influence is highly dependent on the El Nio type. The canonical El Nio is intensified during the positive PDO phase, while, on the con- trary, El Nio Modoki weakens. In future climate the interaction between PDO and El Nio is modified, but the significant intermodel spread does not allow an unambiguous determination of trends.