Geology Faculty Publications

Document Type

Article

Publication Date

10-2015

Publication Source

Hydrology and Earth System Sciences

Abstract

In the Asian monsoon region, variations in the stable isotopic composition of speleothems have often been attributed to the "amount effect". However, an increasing number of studies suggest that the "amount effect" in local precipitation is insignificant or even non-existent. To explore this issue further, we examined the variability of daily stable isotopic composition (δ18O) in precipitation from September 2011 to November 2014 in Nanjing, eastern China. We found that intra-seasonal variations of δ18O during summer were not significantly correlated with local rainfall amount but could be linked to changes in the moisture source location and rainout processes in the source regions. Our findings suggest that the stable isotopes in summer precipitation could signal the location shift of precipitation source regions in the inter-tropical convergence zone (ITCZ) over the course of the monsoon season. As a result, changes in moisture source location and upstream rainout effect should be taken into account when interpreting the stable isotopic composition of speleothems in the Asian monsoon region. In addition, the temperature effect on isotopic variations in non-monsoonal precipitation should also be considered because precipitation in the non-monsoon season accounts for about half of its annual precipitation.

Inclusive pages

4293-4306

ISBN/ISSN

1027-5606

Document Version

Published Version

Comments

This open-access document is provided for download in compliance with the publisher's policy on self-archiving. Permission documentation is on file.

Publisher

European Geosciences Union

Volume

19

Issue

10

Peer Reviewed

yes

Effects of Changes in Moisure Source-LR.pdf (925 kB)
Lower-resolution version of article (less than 1 MB)