Dynamic Processes Governing Lower-Tropospheric HDO/H2O Ratios as Observed from Space and Ground
Christian Frankenberg,1,*
Kei Yoshimura,2
Thorsten Warneke,3
Ilse Aben,1
André Butz,1
Nicholas Deutscher,4
David Griffith,4
Frank Hase,5
Justus Notholt,3
Matthias Schneider,5
Hans Schrijver,1
Thomas Röckmann6
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
and a model study shows that dynamic processes can entirely
compensate for temperature effects on the isotopic composition
of precipitation.
2 Scripps Institution of Oceanography, University of California, La Jolla, CA 92093, USA.
3 Institute of Environmental Physics, Otto-Hahn-Allee 1, Bremen, 28359, Germany.
4 School of Chemistry, University of Wollongong, Wollongong, Australia.
5 Institute for Meteorology and Climate Research, IMK-ASF Karlsruhe, Germany.
6 Institute for Marine and Atmospheric Research Utrecht, Princetonplein 5, Utrecht, 3584 CC, Netherlands.
* To whom correspondence should be addressed. E-mail: C.Frankenberg{at}sron.nl
