New Analysis Reveals Historical Temperature Trends at Beijing Observatory
Long-term climate data often faces inconsistencies due to non-natural factors such as station relocations, changes in instrumentation, and observation practices. These factors introduce biases, complicating the assessment of climatic trends. By homogenizing these data series, researchers aim to correct these biases and derive more reliable conclusions about climate change.
The study employed a new homogenization method for complex daily temperature series. Using more complete historical records and advanced statistical techniques, the researchers identified and adjusted for three primary types of non-climatic biases: station relocations, calculation methods, and measurement transitions.
Adjustments for these biases ranged from -1.13 to 0.63C, -0.29 to 0.23C, and -0.13 to 0.00C, respectively. After these adjustments, the homogenized temperature series showed a significant warming trend of 0.199C per decade from 1915 to 2021, with winter showing the most pronounced increase.
"Compared to previous studies, our new homogenized data takes into account and reduces the impact of three non-natural factors, better reflecting the true changes in temperature," explained Dr. Zhen Li, the corresponding author and Associate Professor at the Institute of Atmospheric Physics. "The previous temperature trends ranged from 0.136 to 0.177C per decade. Our more effective adjustments, especially those accounting for station relocations to more urban areas, revealed a higher warming trend."
The study highlights the necessity and effectiveness of the homogenization process in providing a more accurate picture of climate change. The team also developed the longest continuous daily temperature sequence for Shanghai (1873-2019) and constructed homogenized datasets for China and Greece, facilitating comparative studies of regional climate extremes.
"These collaborative efforts have been invaluable. By combining resources and expertise, we've been able to produce high-quality climate data that is essential for accurate climate change assessments," added Dr. Li.
Research Report:A new method for homogenization of complex daily temperature data: application at Beijing Observatory (1915-2021) and trend analysis
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