Seasonal and regional temperature differences in subtropical China during the past 200 years

Tree ring plays an important role in deciphering the paleoclimatic signals over the past 100-10000 years. However, tree-ring studies from tropical to subtropical regions are rarer than that from extratropical regions, which greatly limit our understanding of some critical climate change issues. Based on tree-ring-width chronologies in different area of Subtropical China (SC), seasonal temperature history of different seasons over the past 200 years were reconstructed. In addition to the warm and cold fluctuations in the reconstructed temperature series, main conclusions are drawn in the following two aspects: 1) Winter-half year temperature had good agreement with summer-time temperature variation in SC at decadal scale, while the winter-half year warming in recent decades was more evident than summer-time. 2) Comparison of the tree-ring based temperature series indicated that the start time of the recent warming in eastern China was regional different. It delayed gradually from north to south, starting at least around 1940 AD in the north part, around 1970 AD in the central part and around 1980s in the south part.