Exceptional drought events over eastern China during the last five centuries

Abstract

Climate extremes, particularly the droughts sustaining over a prolonged period and affecting extended area (defined as "exceptional drought events"), can have long-lasting effects on economic and social activities. Here we use the Chinese drought/flood proxy data of the past five hundred years to identify the cases of exceptional drought events over eastern China (east of 105°E), and to study their spatial patterns and temporal evolutions. The associated circulations for the contemporary case are analyzed using available meteorological data. Possible linkage of these cases to climatic forcing and natural climate events is also explored. After considering the intensity, duration, and spatial coverage, we identified three exceptional drought events, which occurred in 1586-1589, 1638-1641, and 1965-1966 in chronological order. They were the most severe droughts of last five centuries in eastern China, with more than 40% of affected area and the drought center encountered a significant summer rainfall reduction (about 50% or more). These three droughts all developed first in North China (34-40°N), and then either expanded southward or moved to the Yangtze River Valley (27-34°N) and the northern part of the southeastern coastal area (22-27°N). For the 1965-1966 case, the significant reduction of summer precipitation was caused by a weakening of summer monsoon and an anomalous westward and northward displacement of the western Pacific subtropical high. Our analyses also suggest that these three exceptional drought events might be triggered by large volcanic eruptions and amplified by both volcanic eruptions and El Niño events. © 2007 Springer Science+Business Media B.V.