Published In
Geosciences
Document Type
Article
Publication Date
7-2018
Subjects
Climate -- Research, Evaporation (Meteorology), Isotope geology, Geochemistry, Hydrologic cycle, Paleoclimatology
Abstract
Deuterium excess (d-excess) is a second-order stable isotope parameter measured in meteoric water to understand both the source of precipitation and the evolution of moisture during transport. However, the interpretation of d-excess patterns in precipitation is often ambiguous, as changes in moisture source and processes during vapor transport both affect d-excess in non-unique ways. This is particularly true in Asia where continental moisture travels a long distance across diverse environments from unique moisture sources before falling as precipitation. Here, I analyzed published d-excess records from meteoric water throughout Asia to better characterize what influences d-excess values. I conclude that, (1) an increase in d-excess values with elevation up the windward side of mountain ranges and a marked decrease in d-excess into their rain shadows are primarily related to subcloud evaporation as opposed to moisture source mixing; (2) high d-excess values (>10‰) associated with the eastern Mediterranean Sea are lowered across much of Central Asia by the addition of other moisture sources, both oceanic and recycled continental; (3) subcloud evaporation of raindrops is lowering d-excess values of precipitation (
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DOI
10.3390/geosciences8070257
Persistent Identifier
https://archives.pdx.edu/ds/psu/25993
Citation Details
John Bershaw. (2018). Controls on Deuterium Excess across Asia. Geosciences, 8(7), 257.
Description
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).