Possible Underlying Mechanisms of Severe Decadal Droughts in Arid Central Asia During the Last 530 Years: Results From the Last Millennium Climate Reanalysis Project Version 2.0

Abstract

AbstractSevere persistent drought events during the last 530 years are examined in Arid Central Asia (ACA) by using the data with proxy assimilation from the Last Millennium Climate Reanalysis project version 2.0 (LMR v2.0). According to the results from the LMR v2.0, six severe decadal droughts occurred in ACA during the last 530 years and five of them overlap with the results based on the independent reconstructions of Asian summer precipitation, such as the droughts of 1519–1538 CE, 1545–1561 CE, 1621–1658 CE, 1822–1846 CE, and 1964–1983 CE. The climate anomaly patterns are characterized by opposite anomalies between the high‐latitude and midlatitude Eurasia during the first four well‐agreement droughts, with negative precipitation and positive surface level pressure and 500‐hPa geopotential height anomalies located over midlatitude Eurasia and opposite anomalies over high‐latitude Eurasia. Whereas, during the last well‐agreement drought, opposing pattern of the climate variation observed between in ACA and in the Mediterranean with negative precipitation anomalies and positive 500‐hPa geopotential height anomalies in ACA and opposite anomalies in the Mediterranean. The positive Arctic Oscillation/North Atlantic Oscillation influence is found to dominate the droughts of 1621–1658 CE via a northward migration of the westerlies. While the last drought of 1964–1983 CE produced by the combined impacts of the negative Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation via the Silk Road pattern over the midlatitude Eurasian continent.