Using full-traversal addition-subtraction frequency (ASF) method to predict possible el nino events in 2019,2020 and so forth

In this paper, an improved method named addition-subtraction frequency (ASF) method, which is based on commensurability method, is used to predict the possible El Nino events in the future. The paper first introduces commensurability method and clarifies the promotion of ASF method compared with the former. Additionally, this paper uses previous data to research the correct and inaccurate predictions of ASF method. Finally, ASF method is used to predict possible El Nino events in 2019, 2020 and so forth.