Comparison of Simulated and Reconstructed Precipitation in China during the Last Millennium

Abstract

With more and more effects of human activities on natural climate variability,the climate change has becomes more complex in the past 1 000 years,which is the key period for linking the proxy data and instrumental observation periods.Aimed to the scarcity of observation and uncertainty of reconstructed proxy data in this period,climate model is developed as a useful tool for studying paleoclimate.ECHO-G is one of such advanced climate models,but its performance in simulating the rainfall in China has not been examined.In this paper,the datasets of 27 years′ observed precipitation reanalysis data of GPCP in China,500 years′ classified drought and flood data,and proxy data like ice core,tree-ring,lake sediment during the past 1000 years are chosen to examine the performance of the atmosphere-ocean coupled model ECHO-G in simulating precipitation in China.The comparison between GPCP reanalysis and simulated precipitation in each season shows the model well reproduced the spatial distributions of precipitation in China;and the comparison with 500 years′ classified drought and flood data indicates the simulation is in good consistent with the precipitation classification in interdecadal time scale.It is prone to be flood when there is more simulated precipitation,and drought when there is less simulated precipitation.Furthermore,both the simulated and tree-ring reconstructed precipitation show there exit inter-centennial cycle of quasi-200 year and inter-decadal oscillation of 20~30 year,i.e.the simulation well reflects the inter-decadal and inter-centennial variations of precipitation.Compared with the lake sediment,the period with more simulate precipitation is corresponding to low lake salinity,vice versa..In total,simulated results successfully reflect the main temporal and spatial variations of precipitation in China during the last millennium.Furthermore,the EOF analysis reveals there exit different regional differentiation characteristics in simulated precipitation of three different typical climate periods.