Data homogenization involves adjusting biases in raw data—in this case, biases in climate data caused by non-climatic factors such as station relocations and changes in observation protocols and instrumentation—before subsequent application. However, although homogenized data usually represent an improvement compared to the raw data, different homogenization methods produce different results. One way to reduce this uncertainty is to sequentially apply multiple methods, as was the case in this collaborative work between scientists from China (at the Institute of Atmospheric Physics, Chinese Academy of Sciences) and Greece (at the Laboratory of Atmospheric Physics, University of Patras and Hellenic National Meteorological Service).

 

The raw and homogenized annual mean temperature series at Wutaishan station in China and Samos station in Greece, demonstrating the large shifts in temperature series that can be caused by station relocation. (Images by LI Zhen and Athanassios A. Argiriou).

 

The new data show that there has been a much stronger warming trend in China than in Greece since 1960. Meanwhile, the annual total precipitation has increased in China but decreased in Greece during the past several decades. Moreover, the new homogenized climate data present a more reasonable representation than the raw data of the large-scale pattern of climate changes in the two countries. Hence, they provide a high-quality database for studying regional climate variation and change, especially when dealing with extreme weather and climate events in China, Greece, and adjacent regions in Asia and Europe.

 

Datasets can be downloaded from China Science Data bank at https://doi.org/10.57760/sciencedb.01731 and https://doi.org/10.57760/sciencedb.01720.

 

 

Media contact: Ms. LIN Zheng, jennylin@mail.iap.ac.cn