Comparison of Two Methods for Temperature Homogenization and Warming Trend Estimating in Hegang

The operational observation started at Hegang National Basic Meteorological Station (hereinafter referred to as Hegang Meteorological Station) in 1956, and the observation mode was changed from manual to automatic observation in 2003. It was in 2013 that Hegang Meteorological Station was relocated from the old site. These changes may have an impact on the uniformity of the observation data. Six stations around Hegang Meteorological Station with long-term observation and high data quality were selected as references. The reference series was established through the first-order difference method and contrast division processing, and the uniformity test and correction of the temperature series were carried out with the help of RHtestV4 software. The results show that the reference series, which was established based on the data of the new station site, has well filtered out the data discontinuity caused by the relocation and accurately represents the variation characteristics of the average temperature in Hegang Meteorological Station. The series corrected by the quantile matching method (QM) reflects the seasonal differences of temperature changes at this station. The corrected temperature series of Hegang Meteorological Station is more reasonable than that before correction. The correction is based on the new station site. In practice, it is not necessary to correct the data every year, which provides great convenience for data update and application.