Spatial and temporal variability of daily temperature during 1961-2010 in the Yangtze River Basin, China

This study investigated the spatial and temporal variability of daily minimum, mean and maximum temperature and the diurnal temperature range (DTR) in the Yangtze River Basin (YRB) during 1961-2010. Three variability patterns of daily minimum temperature and four variability patterns of daily mean and maximum temperatures were detected. Results indicate that the rugged topography causes more complex temperature variability in the mid YRB, and daily mean temperature shows more complex variability rather than daily minimum and maximum temperatures. Under the control of both topography and atmospheric circle, three temperature variables have mean values decreasing spatially with longitude, although the Sichuan Basin has larger mean values compared with the surrounding areas, and there are smaller variations in the Jinsha River Basin relative to other areas. The variations of three temperature variables became smaller over time. After the 1980s, the three temperature variables show upward trends in most areas of YRB, except in the Jinsha River Basin where complex temperature trends appeared. In the five decades, both negative and positive magnitudes of DTR were detected, reflecting the different upward speeds of daily minimum and maximum temperatures in different areas of YRB. Rapid urbanization caused notably increasing temperature and DTR in the 2000s at the Wuhan and Shanghai urban agglomerations. In summary, the Dongting and Poyang Lake basins and the Yangtze River Delta in YRB are more sensitive and susceptible to climate change.