Next Article in Journal
Coastal Karst Groundwater in the Mediterranean: A Resource to Be Preferably Exploited Onshore, Not from Karst Submarine Springs
Next Article in Special Issue
Establishment of a Greek Food Database for Palaeodiet Reconstruction: Case Study of Human and Fauna Remains from Neolithic to Late Bronze Age from Greece
Previous Article in Journal
The Majella National Park: An Aspiring UNESCO Geopark
Previous Article in Special Issue
Pb Isotope Mapping of Paleoproterozoic Gneisses in the SW Grenville Province: Evidence for a Cryptic Continental Suture
Open AccessArticle

Controls on Deuterium Excess across Asia

Portland State University, Geology Department, 1721 SW Broadway, Portland, OR 97201, USA
Geosciences 2018, 8(7), 257; https://doi.org/10.3390/geosciences8070257
Received: 30 May 2018 / Revised: 28 June 2018 / Accepted: 2 July 2018 / Published: 10 July 2018
(This article belongs to the Special Issue Isotope Geochemistry)
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 (<10‰) throughout the relatively arid Tarim Basin, China; and (4) temporal changes in d-excess values of alpine glaciers do reflect spatio-temporal changes in moisture source, as these samples experience minimal variation in subcloud evaporation. View Full-Text
Keywords: stable isotope geochemistry; meteoric water; Central Asia; evaporation; hydrologic cycle; climate; paleoclimate stable isotope geochemistry; meteoric water; Central Asia; evaporation; hydrologic cycle; climate; paleoclimate
Show Figures

Figure 1

MDPI and ACS Style

Bershaw, J. Controls on Deuterium Excess across Asia. Geosciences 2018, 8, 257.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop