Relationship between early summer precipitation in Japan and the El Nino-Southern and Pacific Decadal Oscillations over the past 400 years

摘要

The El Nino-Southern Oscillation (ENSO) appears to strongly influence East Asian Summer Monsoon (EASM) rainfall, but the relatively short instrumental rainfall record hinders the development of a longer-term understanding of this teleconnection. To partially overcome this issue, here we reconstruct precipitation from tree-ring oxygen isotopes (delta O-18) in central Japan during AD 1612-1935. Our results indicate that tree-ring cellulose delta O-18 is significantly correlated with May-June (MJ) precipitation, allowing us to investigate the link between the EASM summer rainfall and ENSO over the past 400 years. Time-and frequency-domain comparison of the tree-ring delta O-18 record and recent ENSO reconstructions reveal a common high-frequency (3-8 year) variability that characterized the mid-17th, late 18th and late 19th centuries. Similar analyses of instrumental MJ precipitation and several ENSO indexes during the 20th century indicate that this high-frequency oscillation reappeared from AD 1980. Comparison of ENSO and Pacific Decadal Oscillation (PDO) indexes indicates that the ENSO-EASM teleconnection is strong when ENSO variance is high, and the PDO phase may modulate the ENSO-EASM relationship over the past 400 years. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.