Late Holocene Climatic And Environmental Changes In Arid Central Asia

摘要

Late Holocene climate and environmental changes in arid central Asia were analyzed using various paleoclimate archives such as ice cores, tree rings, lake sediments, historical documents, glacial fluctuations and archeological data. Over the last 2000 years, arid central Asia witnessed three humid periods from AD 0-410, 650-890 and 1500-1820s. Dry periods occurred in 420-660 and in 900-1510s. Concerning temperature, the most striking features are the existence of the Medieval Warm Period (MWP) and the Little Ice Age (LIA). The MWP was recorded in the 9-12th centuries and was accompanied by an anomalously dry climate, whereas the LIA extended from the 15-18th centuries and was accompanied by pluvial conditions. Temperature and precipitation show significantly negative correlations on annual, decadal and centennial timescales. Temperature was generally above average when dry climate conditions predominated on decadal to centennial timescales during the last 1000 years. The coldest decades of the last millennium, the period 1630-1650s, matched with an anomalously wet episode. The combination of paleoclimatic evidence clearly suggests that the combination of cold and wet climate condition during the LIA was responsible for the strong glacial advances in several mountain systems of central Asia.