Climatic changes in the twenty-four solar terms during 1960–2008

The temperature thresholds and timings of the 24 climatic Solar Terms in China are determined from a homogenized dataset of
the surface air temperature recorded at 549 meteorological stations for the period 1960–2008 employing the ensemble empirical
mode decomposition method. Changes in the mean temperature and timing of the climatic solar terms are illustrated. The results
show that in terms of the mean situation over China, the number of cold days such as those of Slight Cold and Great Cold has
decreased, especially by 56.8% for Great Cold in the last 10 years (1998–2007) compared with in the 1960s. The number of hot
days like those of Great Heat has increased by 81.4% in the last 10 years compared with in the 1960s. The timings of the climatic
Solar Terms during the warming period (around spring) in the seasonal cycle have advanced significantly by more than 6 d, especially by 15 d for Rain Water, while those during the cooling period (around autumn) have delayed significantly by 5–6 d. These characteristics are mainly due to a warming shift of the whole seasonal cycle under global warmin