Dynamic Processes Governing Lower-Tropospheric HDO/H_2O Ratios as Observed from Space and Ground
Abstract
The hydrological cycle and its response to environmental variability such as temperature changes is of prime importance for climate reconstruction and prediction. We retrieved deuterated water/water (HDO/H_2O) abundances using spaceborne absorption spectroscopy, providing an almost global perspective on the near-surface distribution of water vapor isotopologs. We observed an unexpectedly high HDO/H_2O seasonality in the inner Sahel region, pointing to a strong isotopic depletion in the subsiding branch of the Hadley circulation and its misrepresentation in general circulation models. An extension of the analysis at high latitudes using ground-based observations of δD and a model study shows that dynamic processes can entirely compensate for temperature effects on the isotopic composition of precipitation.
Additional Information
© 2009 American Association for the Advancement of Science. Received 19 March 2009; accepted 22 July 2009. We thank all the scientists and engineers involved in the ESA's ENVISAT/SCIAMACHY mission, especially J. P. Burrows and H. Bovensmann from the University of Bremen, and, apart from the ESA, the national space agencies of Germany [German Aerospace Center (DLR)], Netherlands [Netherlands Space Office (NSO)], and Belgium [Belgian User Support and Operations Center (BUSOC)]. The ground-based FTS activities at Kiruna and Izaña were supported by the Deutsche Forschungsgemeinschaft through project RISOTO. We are grateful to the Alfred Wegener Institute for providing the FTIR instrument and logistical support in Ny Ålesund. Financial support from the European Union project GEOMON for the FTS stations is acknowledged. We thank H. Sodemann for a valuable discussion on an earlier manuscript draft; R. Snel, R. van Hees, and P. van der Meer for their work on instrument calibration; and A. de Lange and P. Tol for proofreading and image creation, respectively. C.F. was supported by a VENI fellowship from the Dutch science foundation NWO.Attached Files
Supplemental Material - 1173791s1.mov
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Additional details
- Eprint ID
- 57375
- Resolver ID
- CaltechAUTHORS:20150508-102404837
- Deutsche Forschungsgemeinschaft (DFG)
- European Union Project GEOMON
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
- Created
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2015-05-08Created from EPrint's datestamp field
- Updated
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2020-03-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences