Change in precipitation over the Asian continent from 1901-2016 based on a new multi-source dataset

Asia experiences great regional differences in climatic variations, especially precipitation. Examining changes in precipitation will help us understand large-scale hydro-cycle processes against the background of global climate change. We used a new multi-source dataset of historical global land precipitation records developed by the China Meteorological Administration to analyze long-term change in annual and seasonal precipitation in Asia during 1901-2016. To solve the problem of inhomogeneity, the Russian Bias-corrected Monthly Precipitation dataset was also used for Russia. The normalized precipitation anomaly (NPA) was used to analyze spatial and temporal precipitation trend patterns. Regional average time series for the continent and its 6 subregions were obtained by an area-weighted averaging method. Results show that: (1) regional average annual precipitation increased significantly during this period, and the upward trend was mainly related to a shift in cold areas during the mid-20th century; (2) regional average spring and autumn precipitation amounts had similar characteristics to those of the long-term changes in annual precipitation, and winter precipitation increased slightly for the entire period, with a significant jump occurring from 1945-1955; (3) North and Central Asia experienced a significant upward trend in precipitation for every season except summer during 1901-2016, while South Asia witnessed a significant downward trend in winter during the same period; (4) during 1901-2016, the proportion of summer precipitation declined uniformly in most parts of the continent, with a significant decline in cold areas. Although there are still uncertainties related to the observational data, the analysis results will help in understanding the general pattern of precipitation variation and the possible response of these regions to global climate change.