An improved Method for determining optimal period of record under climate change

The length of record is an important factor for the selection of climatic design parameters used in the air-conditioning system design. Under the background of climate change, the traditional 30-year period will no longer apply. Therefore, a new method for determining the Optimal Period of Record (OPR) is proposed. First, the Optimal Prediction Period (OPP) was determined by evaluating the prediction effect of selected climatic design parameters on the future extreme climatic parameters. Then, the Minimum Fluctuation Period (MFP) that can filter out the fluctuation of the climate system was determined based on the wavelet analysis. Finally, the OPR was determined by the OPP and MFP. Taking five cities in China as examples, the OPR was obtained respectively. It was found that the OPR was between 12 and 13 years in most cities. The further analysis showed that the OPR can better reflect the influence of climate change on the climatic design parameters.