Warming substantiated by multiple sine functions decomposition of multiple cities´ temperature data

In recent years, extensive efforts have been committed to the temperature forecast work, and more and more studies have indicated that the temperature is rising. For the purpose of forecasting long-term temperature trend, a temperature forecast method named multiple sine functions decomposition (MSFD) method is presented in this paper. Based on the numerical experiments for 12 Asia-Pacific (APAC) cities, the efficacy of the MSFD method and the warming trend of APAC region are substantiated. The core concept of the MSFD method is that, by decomposing a historical temperature sequence into sine waveforms, multiple sine functions are thus obtained and applied to forecasting the future temperature trend. Different degrees of warming in the ensuing 200 years are forecasted from the results of numerical experiments. In addition, we find that the high-latitude cities are generally more evident in terms of temperature change compared with those low-latitude cities. In summary, with the most possibility, the general temperature trend of APAC region is upward.