NOAA/WDS Paleoclimatology - West Qinling 500 Year Precipitation Reconstruction

The West Qinling Mountains form part of the climatic barrier that separates southern and northern China, and are located at the edge of the region dominated by the Asian summer monsoon. To investigate the spatial distribution of regional hydroclimatic variability in the West Qinling region, the annually resolved spatial field of rainy season (May-June-July-August-September, MJJAS) precipitation anomalies from AD 1470 to 2000 was reconstructed using 39 tree-ring chronologies, as well as 28 dryness/wetness indices derived from historical documentary data. The results indicate that the El Nino-Southern Oscillation (ENSO) and the Tropospheric Biennial Oscillation (TBO) may jointly affect the spatial pattern of precipitation over the West Qinling Mountains at inter-annual timescales. The drought in the 1990s was found to exceed the amplitude and duration of all other periods of drought that have occurred since AD 1470 in this region. The new precipitation field reconstruction assesses the spatial pattern of historical hydroclimatic variability in the West Qinling region and provides an opportunity to test the performance of climate models in simulating regional precipitation variability and change.